Guide: Porsche 911 SC - a Historical and Technical Appraisal

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BACKGROUND

By mid 1977, the 911 had been around for 13 years and Porsche did not expect to be building it for much longer. Instead, the company (which had been under the direction of Ernst Fuhrmann since 1972) thought the future lay with conventional front-engined models like the recently introduced 928 and 924.

However, the 911 was still an immensely popular machine and routinely outsold the 928 by around 20:1.

Over time, Porsche had broadened the 911’s appeal beyond the scope of enthusiastic drivers that were prepared to overlook its idiosyncrasies. Thanks to industry-leading reliability, iconic looks, superb build quality, spacious packaging, fuel efficient engines and easy operation, 911s were frequently purchased for business and family use by both men and women.

This unusual combination of attributes meant it occupied a unique position in the automotive world.

Another factor that had ensured the 911’s ongoing success was how Porsche handled draconian safety and emissions legislation introduced throughout the 1970s. Thanks to innovative impact bumpers and clean engines, Porsche had been able to continue selling good looking cars around the world.

By contrast, many high performance European machines were blighted with ugly safety equipment while a good number were frozen out of the lucrative US market altogether.

Despite the mid 1970s Oil Crisis and a worldwide economic slump, Porsche sales had remained strong and the firm emerged from a troubled few years in better shape than any of their rivals.

Throughout this time, 911 production had averaged around 10,000 units every year. Different engine options had been available along with a choice of Coupe and Targa body styles.

When the turbocharged 930 arrived in 1975, Porsche were also able to offer a 911 with supercar rivalling performance.

For the 1978 model year K-series 911 (production of which got underway in August 1977), Porsche introduced what was forecast to be the final iteration of the 911. As a result there was no major investment in new equipment.

CHASSIS

Unlike its predecessors, the new 911 SC (Super Carrera) was offered in just one state of tune.

It was based on many of the same components as the outgoing 911 3.0 Carrera.

At its core was the galvanised unitary steel bodyshell that had been introduced for the 1974 model year.

Updates included beefier anti-roll bars and a thicker rear torsion bar. For the first time, a brake servo was fitted which reduced pedal effort especially when cold.

Suspension was fully independent with torsion bars and telescopic shocks plus an anti-roll bar at either end. The front used a compact MacPherson strut arrangement with a single lower wishbone. At the rear, semi-trailing arms were installed.

Ventilated disc brakes were fitted all round.

The standard wheels were 15-inch Dunlop-shod ATS ‘Cookie Cutter’ rims that measured 6-inches wide at the front and 7-inches wide at the rear. Forged Fuchs alloys with Pirelli P7 tyres were optional.

An 80-litre fuel tank was located underneath the front lid.

ENGINE / TRANSMISSION

In the engine bay was a de-tuned version of the 3.0 Carrera power unit that had been on offer during the 1976 and 1977 model years. This was itself a normally aspirated version of the engine used in the turbocharged 930.

Designated Type 930/03, this all-alloy Flat 6 featured single overhead camshafts, two valves per cylinder and dry-sump lubrication.

New equipment included a crankshaft with larger main and con rod bearings, a cast aluminium crankcase (instead of magnesium), Nikasil barrels, an eleven-blade cooling fan and milder camshafts. Camshaft chain noise was reduced by fitting new chain guides. There was also new contactless ignition.

Displacement was unchanged at 2994cc thanks to a bore and stroke of 95mm and 70.4mm respectively.

Likewise, compression stayed at 8.5:1.

Fuel-injection was courtesy of the eponymous Bosch K-Jetronic and every 911 SC came with an air injection pump.

Peak power was 180bhp at 5500rpm. This was 15bhp up on the outgoing 911 S that had been available in the USA but 20bhp down on the 3.0 Carrera retailed in other markets. However, the torque rating was much improved with 195lb-ft at 4200rpm.

Transmission was via a Type 915/44 five-speed gearbox.

BODYWORK

Cosmetically, the 911 SC was practically identical to the 3.0 Carrera which had used flared rear fenders to accommodate its 7-inch wide rear wheels.

At this stage, chrome body trim for the headlight shrouds, window frames and door handles was still standard although the Black Look option was becoming increasingly popular.

Otherwise, the 911 SC was largely the same as every other post 1974 model year G-body 911 with an unmistakable silhouette recognised the world over.

Body panels were manufactured exclusively from steel with the exception of the aluminium bumpers.

INTERIOR

Little was changed inside where the dash, five-gauge instrument binnacle and steering wheel were carried over from previous iterations. Porsche also retained the existing high-backed seats and door panels.

Among the minor updates was a new 7000rpm rev counter.

Manual windows were still standard in many markets.

Upholstery options included pinstripe or tartan velour with matching door trim. Leather was available only as an optional extra.

OPTIONS

Other optional upgrades included air-conditioning, electric windows, an electric sunroof, sports seats, front and rear spoilers, Bilstein gas-filled dampers, a range of audio equipment and Martini decals. Also available were the aforementioned 16-inch Fuchs wheels with Pirelli P7 tyres along with the Black Pack.

Some importers bundled options together like in the UK where spoilers, Bilstein dampers, Fuchs alloys and sports seats were referred to as the Sport package.

WEIGHT / PERFORMANCE

The standard 911 SC Coupe weighed in at 1160kg and the Targa was 1210kg.

Porsche quoted a top speed of 140mph and 0-62mph time of 6.4 seconds. This compared to 149mph and 6.2 seconds for the outgoing Carrera 3.0.

USA VERSION

US variants were 30kg heavier owing to additional emissions equipment that included a two-way catalytic converter.

Instead of the Type 930/03 engine fitted to other derivatives, the US-spec. 911 SC was supplied with either a Type 930/04 engine or Type 930/06 engine if destined for sale in California.

Japanese market 911 SCs came with their own special motor designated Type 930/05.

1978 EAST AFRICAN SAFARI RALLY

Having already won every other major rally, and to publicise the new 911 SC, in March 1978 Porsche took another crack at what was the most daunting contest on the World Championship calendar: the East African Safari.

For this latest attack (Porsche’s first works rally outing since the ‘74 Safari) a trio of suitably enhanced Martini-backed 911 SCs were prepared (covered in detail separately). Although disappointed not to win, second and fourth places for the lightly modified SC was a fine result and Porsche proved the only manufacturer to get all its cars to the finish.

END OF 1978 MODEL YEAR K-SERIES PRODUCTION

Production of the 1978 model year K-series 911 SC began in August 1977 and ran for twelve months. During this time 5178 Coupes and 4308 Targas were completed.

1979 MODEL YEAR L-SERIES

The 1979 model year L-series 911 SC followed from August 1978.

Aside from some new colours and revised gear ratios, no major changes were made although Porsche quietly introduced a tuning kit for SC owners that were unhappy with the loss of power compared to the 3.0 Carrera. Only available through Porsche’s Werk 1 facility in Zuffenhausen, the Tuning Kit involved installing larger bores and increasing the compression ratio but added 20% to the car’s price.

In total, 5705 Coupes and 5284 Targas were built during the 1979 model year.

1980 MODEL YEAR A-SERIES

For the 1980 model year, Porsche switched to a new 17 digit chassis numbering sequence to replace the existing 10 digit arrangement. Instead of O-series, these 1980 model year cars reverted to an A-series designation.

By this time, Porsche had decided not to discontinue the 911 and calls for more power led to the introduction of a 188bhp engine for markets outside of the USA and Japan.

The uprated Type 930/09 motor came with revised ignition, new camshaft timing and a new timing chain tensioner idler arm. Compression was increased from 8.5:1 to 8.6:1 and the front wing oil cooler was modified to improve heat dissipation. Peak output was 188bhp at 5500rpm but the torque rating was unchanged.

A-series 911 SCs bound for the USA stayed at 180bhp but now came with a three-way catalytic converter and Lambda sensor. To avoid any power loss, the compression ratio was increased to 9.3:1. This new Type 930/07 engine was legal in all 50 states.

Similarly equipped Japanese-spec. 911 SCs were supplied with a Type 930/08 engine.

As a result of dwindling demand, the Sportomatic transmission option was finally dropped.

Cosmetically, the 1980 model year SC came with the Black Look as standard. All cars now came with body coloured headlight shrouds as well.

Inside, the Turbo’s centre console was adopted throughout the range along with a small diameter steering wheel. The rear seat centres were now upholstered to match those in the front.

New options included an alarm and Boge dampers. There was also a new type of warped cheque-pattern seat centre known as Pascha trim which joined the existing pinstripe and tartan offerings.

UK cars came with a stereo and electric antenna as standard.

All cars destined for the USA were now equipped with electric windows and air-conditioning.

911 SC WEISSACH SPECIAL EDITION

Porsche also produced a batch of 400 Weissach Special Editions for the US market during the 1980 model year.

They came with fog lights, an electric sunroof, Bilstein dampers, Fuchs wheels with body coloured centres and the spoiler pack. The Weissach Special Edition was available in black or platinum metallic with a grey leather interior and burgundy piping.

1980 model year A-series 911 SC production totals were 4831 Coupes and 4272 Targas.

1981 MODEL YEAR B-SERIES

For the 1981 model year B-series 911 SC that was introduced in August 1980, Porsche further uprated the 911 SC with a new Type 930/10 engine that boasted an additional 16bhp.

Compression was increased from 8.6:1 to 9.8:1 and improved Bosch K-Jetronic offered better fuel efficiency.

Peak output was now 204bhp at 5900rpm and the torque rating was 197lb-ft at 4300rpm (up from 195lb-ft at 4200rpm).

Unfortunately, the Type 930/10 engine was not available in the USA or Japan.

Thicker anti-roll bars were fitted to all B-series 911 SCs along with rectangular side repeaters on the front fenders. The anti-corrosion warranty was increased to seven years. A new Sports seat design was added to the options list along with Berber tweed trim.

1981 model year production totalled 4876 Coupes and 3120 Targas.

1982 MODEL YEAR C-SERIES

The 1982 model year C-series 911 SC went into production during August 1981. The most significant universal change was an improved heating system that provided more heat at low engine speeds. The Turbo-spec. rear spoiler was switched to one with a slimmer profile.

911 SC FERRY PORSCHE SPECIAL EDITION

There was also another special edition, the Ferry Porsche, which was introduced to celebrate Porsche’s 50th anniversary as an auto maker. 200 were built, all of which were finished in Meteor Metallic Grey with burgundy leather and Turbo spoilers.

A prototype 911 SC Cabriolet was then previewed at the Geneva Motor Show in March 1982.

1982 model year production totalled 5892 Coupes and 4163 Targas. There were also four M439-optioned flat nosed Sonderwunsch examples (covered separately).

1983 MODEL YEAR D-SERIES

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The 1983 model year D-series 911 SC was the last before the 3.2-litre Carrera was introduced. Production started in August 1982.

There was a new exhaust silencer to meet tightening noise requirements while the rear seats could now be equipped with optional three-point safety belts.

More significantly, a 911 SC Cabriolet entered production in October 1982. It featured a reinforced bodyshell and manually operated triple layer hood that was quick and easy to use. Cabriolets came with leather seats and two wing mirrors as standard.

Right-hand drive SC Cabriolet’s were available from February 1983.

D-series production totals were 5761 Coupes, 2688 Targas and 4187 Cabriolets. There was also one Sonderwunsch Coupe.

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Blown Logic - a Historical & Technical Appraisal of the Porsche 911 3.0 Turbo (930)

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BACKGROUND

The 2.7-litre Carrera RS introduced for model year 1973 was Porsche’s first 911-based homologation special and spawned a series of dominant racing variants that annihilated the opposition.

Less expected than its on-track success, the 2.7 RS also became a commercial hit. Porsche had only planned to build 500 units to qualify for the FIA’s Group 4 class. However, over 1500 were eventually sold which also enabled the model to go racing in Group 3 which had a 1000-car stipulation.

For 1976, the FIA made several changes to the existing racing categories. Production requirements for the Group 4 Grand Touring class were reduced from 500 units in twelve months to 400 units in 24-months.

The existing Group 5 class for three-litre Sports Prototypes became Group 6.

As for Group 5, that became a Special Production Car class for more heavily modified versions of machines that had already been homologated in Groups 1 through 4. Major changes were permitted so long as the standard bonnet, roof and door profile of the base car was retained. This led to Group 5 sometimes being referred to as a Silhouette formula.

With Groups 4 and 5 in mind, Porsche created their second 911-based homologation special: the turbocharged 930.

By this time, the firm was already experienced in the art of forced induction - between 1972 and 1973 they had successfully campaigned the 917/10 and 917/30 Group 7 cars which were followed by the experimental 2.2-litre Carrera RSR Turbos of 1974.

Like the 2.7 Carrera RS, the 930 proved another big seller. It was actually so popular that Porsche quickly decided to make the 911 Turbo a permanent fixture in their model line up. Just as importantly, the Group 4 934 and Group 5 935 racing cars were enormously successful and dominated their respective categories for almost a decade.

The first (engine-less) 930 mock-up (chassis 9113300157) was displayed at the Frankfurt Motor Show in October 1973. At this stage, the silver and white-striped prototype retained many 3.0 Carrera RS features to include the bumpers, fenders, wheels and seats.

A narrow-bodied 911 2.7 Carrera Turbo prototype was built in early 1974 (chassis 9115600042). Having served as a development car, it was refurbished and gifted to Ferry Porsche’s sister, Louise, on her 70th birthday in August 1974.

The more-or-less production-ready 930 was unveiled at Frankfurt in October 1974. At this stage it famously featured cross-drilled and ventilated discs from the legendary 917, but for production Porsche simply imported the contemporary 911 arrangement for reasons of longevity.

930 production started in February 1975 on the H-series platform. It was an immediate success and demand outstripped supply.

The 400 cars required by Group 4 had been produced by the end of 1975 and homologation was approved on December 6th. By this time, the 1976 model year I-series 911 Turbo was in production.

CHASSIS

930s were based around the contemporary 911’s standard steel bodyshell.

Steering was non-assisted and an 80-litre fuel tank was imported from the regular 911 and similarly mounted under the front lid.

Suspension was lifted from the 1974 model year 3.0 Carrera RS. Up front were MacPherson struts with lower wishbones, longitudinal torsion bars and anti-dive geometry. The back end used semi-trailing arms with anti-squat.

Bilstein shocks were fitted all round and along with an anti-roll bar at either end.

Dual circuit brakes ran separate systems for each axle. Discs and calipers were sourced from the 2.7-litre Carrera. Disc diameter was 282.5mm front and 290mm rear.

Forged light alloy wheels were supplied by Fuchs with 15 x 7-inch rims at the front and 15 x 8s at the back. These were normally shod with Dunlop or Pirelli tyres (205/50 and 225/50 respectively).

Compared to the 1975 model year 911 2.7 Carrera, track was 60mm wider at the front and 108mm wider at the rear.

ENGINE / TRANSMISSION

The 930’s air-cooled all-alloy Flat-6 motor was developed from the 1974 3.0 Carrera RSR power unit.

As usual, it came with dry-sump lubrication and single overhead cam two-valve heads.

Designated Type 930/50, the new motor featured forged alloy pistons with Nikasil barrels along with a lightweight aluminium crankcase.

Displacement was 2994cc thanks to a bore and stroke of 95mm and 70.4mm respectively with the former having been taken out by 5mm over the existing 2.7-litre engine.

A single KKK 3 LDZ turbo ran at 0.8 bar. The compression ratio was dropped to 6.5:1 in order to limit full boost compression to 11.7:1.

Fuel-injection was via Bosch’s familiar K-Jetronic system.

Peak output was 260bhp at 5500rpm and 253lb-ft at 4000rpm.

For comparison, the most potent normally aspirated 911 of the time (the 911 2.7 Carrera) pumped out 210bhp at 6300rpm / 188lb-ft at 5100rpm.

A new Type 930/30 aluminium-cased four-speed gearbox was installed as Porsche were concerned about stripping gears in the regular 915 ‘box. They deemed the level of torque so great that a five-speed unit was unnecessary.

BODYWORK

The 930 was initially only available as a Coupe.

It most obviously differed from normally aspirated 911s by way of its dramatically flared wheelarches and some special new aero.

To keep the front end pinned, a matt black wraparound chin spoiler was installed.

Integrated with the engine cover was a Tea Tray rear spoiler from the 3.0 Carrera RS adapted to incorporate an additional cooling slot.

Down each flank were the 911’s fattest fenders yet. By the time production got fully underway, a satin black shark fin-style stone guard was added to protect the rear arches from road rash.

Satin black window frames were standard with traditional bright metal work a no-cost option.

Steel body panels were used throughout.

Although the 911 Turbo may have lacked the visual drama of a Ferrari Berlinetta Boxer or Lamborghini Countach, for many customers that was a large part of its appeal. Uniquely among its peers, the 930 packed a supercar punch in a relatively discrete package that was genuinely practical enough for prolonged everyday use.

INTERIOR

The familiar 911 cockpit was equipped to a very high standard. Despite being a homologation special, the emphasis was on luxury.

930s came with half leather sports seats that featured new tartan fabric centres plus door panels trimmed to match.

A small diameter three-spoke steering wheel was upholstered in leather and extra sound insulation was fitted along with deep pile carpet.

An 8000rpm rev counter replaced the 7000rpm tach fitted to regular 911s. A boost gauge was not yet fitted to production cars. Off to the left of the rev counter were combined read outs for oil pressure / oil temperature and oil level / fuel. To the right was a 300kmh / 180mph speedo and a clock.

Standard equipment included electric windows, a four-speaker stereo with front fender-mounted electric antenna, a rear wiper, headlight washers and fog lights.

OPTIONS

Via the options list, customers could add a ZF limited-slip differential, rear fog lights, air-conditioning, an electric sunroof and a centre console.

Further customisation was available by special request - a perfect illustration of how Porsche’s customer racing department could create a VIP Spezial was chassis 9305700208 ordered by Austrian conductor, Herbert von Karajan.

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A serial Porsche owner, von Karajan’s silver 930 (an H-series 1975 MY car from the first year of production) was equipped with a tuned engine, a roll cage, bright metal window frames and an elaborate Martini Turbo decal kit. It featured on the front cover of his best-selling Famous Overtures album and was later further uprated with Cibie spot lamps and racing-style seats.

WEIGHT / PERFORMANCE

The 930 weighed in at 1195kg, had a top speed of 154mph and could sprint from 0-62mph in 5.7 seconds.

It catapulted Porsche into elite performance car territory, but the 930 was considerably less expensive than most of its rivals.

1975 MODEL YEAR H-SERIES

284 H-series 1975 model year 930s were built during the first months of production (February 1975 to August 1975). All were left-hand drive.

1976 MODEL YEAR I-SERIES

1976 model year production began in September 1975.

Boost pressure was increased from 0.8 to 1.0 bar and the turbo was enhanced with a by-pass valve to bring the power in more progressively.

Pirelli’s new low profile P7 tyres were now fitted as standard.

Also noteworthy was a new six-year anti-corrosion warranty that far-exceeded the guarantee given by any other high performance manufacturer at the time.

There were changes to the options list too: 16-inch diameter wheels became available (with a 4.222 final drive ratio) as did right-hand drive, a full leather interior and a cool Turbo-branded decal kit.

A mid year update (which came on stream during the spring of 1976) saw the rear spoiler’s supplementary cooling slot made into a much larger grille.

USA VERSION

North American customers were supplied with a US-legal 930 for the first time during the 1976 model year. These cars featured a revised Type 930/51 engine with additional emissions equipment that cost 15bhp. Peak power was now 245bhp at an unchanged 5500rpm.

Like other US-bound 911s of the era, the 930 (branded in the US as the Turbo Carrera) typically came with tailored sugar scoop headlights, extended amber front signals, red instead of amber rear signals and beefier rear bumperettes.

1977 MODEL YEAR J-SERIES

For the 1977 model year J-series (production of which began in September 1976), Porsche introduced further updates.

A Hydrovac brake servo was installed on left-hand drive 930s to allow easier depression of the brake pedal.

Thicker 20mm anti-roll bars were fitted (up from 18mm).

16-inch Fuchs alloys and centre console became standard.

A boost gauge was added (within the tach), twin fuel pumps were fitted, the synchromesh on first and second gear was revised and the differential assembly strengthened.

The engine type number was changed from 930/50 to 930/52 and, in the case of US-market cars, from 930/51 to 930/53.

An optional Martini stripe kit was also introduced. It came after a unique ‘Martini Turbo’ was produced for the British Motor Show in October 1976. This show car also had special Fuhrmann orthopaedic seats trimmed in Martini colours. These Fuhrmann seats became an expensive but rarely seen option.

END OF PRODUCTION

The 1977 model year 930s were the last 3-litre cars built.

For the 1978 model year, an uprated 3.3-litre engine was introduced.

By the time production ended in August 1977, a total of 2880 three-litre 930s had been completed.

1623 of these were the 260bhp variants and the remaining 1257 were 245bhp US-bound derivatives.

Production tallies are as follows:

1975 model year H-series, Type 930/50 engine, 284 examples built, VIN range 9305700001 to 0284
1976 model year I-series, Type 930/50 engine, 644 examples built, VIN range 9306700001 to 0644
1976 model year I-series USA version, Type 930/51 engine, 530 examples built, VIN range 9306800001 to 0530
1977 model year J-series, Type 930/52 engine, 695 examples built, VIN range 9307700001 to 0695
1977 model year J-series USA version, Type 930/53 engine, 727 examples built, VIN range 9307800001 to 0727

COMPETITION HISTORY

The 400 cars required for homologation had been produced by the end of 1975 and the 930 was approved for Group 4 / 5 on December 6th.

For the first time at World Championship level, 1976 saw production-based GT cars and purpose-built Sports Prototypes contest separate series. Porsche ran the Group 6 936 for what was dubbed the World Championship for Sports cars. The factory also ran works 935s in the production-based World Championship for Makes where cars from Groups 5 through 1 were permitted.

Porsche kept the 935 for works use in 1976 and won four out of seven World Championship events (the 6 Hour races at Mugello, Vallelunga, Watkins Glen and Dijon). Three wins went to the 3.5-litre BMW E9 CSL which meant Porsche took championship honours. Porsche also won Group 5 at the Le Mans 24 Hours with a fourth place finish overall.

Customer 935s were supplied for 1977 onwards and the BMW challenge for outright honours faded away as it looked to dominate the under 2-litre class Group 5 class with the E21 320. From this point, if the factory Porsche team didn’t win on its increasingly infrequent outings, a privateer car was normally able to pick up the win.

The 935 subsequently dominated all championships organised to Group 5 regulations: the World Sportscar Championship, IMSA, Germany’s domestic Deutsche Rennsport Meisterschaft, Trans-Am and of course, at Le Mans.

It was a similar story with the 934 although Porsche supplied these cars exclusively to customers and did not contest Group 4 in an official capacity. From 1976 until the end of that decade, the 934 out-scored any of its rivals in terms of major class wins by a quite enormous margin. Group 4 honours in all the aforementioned championships similarly fell the 934s way.

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 3.0 Carrera RS - a Historical & Technical Appraisal

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BACKGROUND

When Porsche created the hardcore 911 2.7 Carrera RS for the 1973 model year, many of the company’s senior managers were not convinced it would be easy to sell the 500 cars needed to qualify for Group 4 GT racing.

However, as it transpired the firm was inundated with orders from the moment the new car broke cover at the Paris Motor Show in October 1972.

Ultimately, demand proved sufficient that over 1500 examples of the high performance driver-focused model were sold within a matter of months.

Porsche’s decision to create the 2.7 Carrera RS was part of a wider move away from Prototype racing in favour of production-based Grand Touring machinery that more closely resembled the kind of vehicles customers could find at their local main dealer.

During the course of 1973, the Group 4 racing version of the 2.7 Carrera RS (the 2.8 Carrera RSR) became the dominant car in its class and routinely vanquished much bigger engined machinery from Ferrari, De Tomaso and Chevrolet. Like the RS, the RSR also proved a commercial hit and 49 were sold to customer teams and privateers.

Not willing to rest on their laurels, Porsche subsequently decided to build a pair of even more extreme 911s in anticipation of the 1974 season.

At the time, the FIA’s Evolution rule permitted manufacturers to create a further uprated version of the already homologated base car so long as a minimum of 50 units were completed. The Evolution base car could in turn then be used as the starting point for an even more radical competition version.

With this in mind, Porsche produced the legendary 911 3.0 Carrera RS which went on to spawn another utterly dominant RSR version.

The first 3.0 Carrera RS was completed in October 1973 and the FIA homologated the model on April 1st 1974 following the completion of 50 units.

Despite having been priced at nearly twice as much as the outgoing 2.7-litre version, Porsche had no trouble selling their latest Renn Sport 911 and 56 were eventually completed.

In addition to an array of performance upgrades, the 911 3.0 Carrera RS was most notably based on the significantly revised 1974 model year G-body platform with its impact-absorbing bumpers.

CHASSIS

Each 3.0 Carrera RS started life as a standard unitary steel 911 bodyshell without any rustproofing or sound deadening.

Suspension was fully independent with torsion bars and telescopic shocks. The front end used a compact MacPherson strut arrangement with a single lower wishbone while semi-trailing arms were installed at the rear. Gas-filled Bilstein dampers were fitted all round.

3.0 Carrera RS-specific equipment included RSR-style revised inner pivot points for the rear suspension, reinforced rear trailing arms with solid bushes and thicker adjustable anti-roll bars (19mm front and 26mm rear).

The brake system was uprated over the outgoing 2.7 with 917 / RSR-style cross drilled and ventilated 300mm discs and finned four-piston calipers.

Forged 15-inch diameter Fuch alloy wheels measured 8 and 9-inches wide front-to-rear respectively. They were originally shod with 215/60 and 235/60 VR 15 Pirelli CN 36 tyres. Compared to the 2.7 RS, track was 65mm wider up front and 58mm wider at the back.

An 80-litre fuel tank was housed underneath the front lid.

ENGINE / TRANSMISSION

In the engine bay was a dry-sumped Type 911/77 Flat 6 motor with cast-iron block and light alloy single overhead cam heads running two valves per cylinder.

Compared to the outgoing 2.7 RS, each cylinder bore was enlarged from 90mm to 95mm. Capacity went from 2687cc to 2993cc as a result (a gain of 306cc). Stroke travel was kept at 70.4mm which ensured the new engine was no less responsive than before.

Because the enlarged cylinder bores would not have left enough magnesium to safely run with circa 330bhp in RSR trim, Porsche elected to fit a stronger die-cast aluminium crankcase. Aluminium cylinders were Nikasil-plated.

Additional cooling came by way of a large engine oil radiator mounted under the front bumper.

Four-bearing camshafts from the new RSR were installed.

Mechanical fuel-injection was courtesy of the same Bosch K-Jetronic system used by the outgoing 2.7 RS.

With a compression ratio of 9.8:1 Porsche claimed peak output figures of 230bhp at 6200rpm and 203lb-ft at 5000rpm.

For comparison, the 2.7 RS had pumped out 210bhp at 6300rpm and 188lb-ft at 5100rpm.

Transmission was through a five-speed 915 gearbox, single-plate clutch and limited-slip differential with 80% locking factory. As per the RSR, a transmission oil cooler was installed complete with integrated pump built into the gearbox end cover.

BODYWORK

In order to comply with ever-tightening safety legislation emanating from the USA, Porsche added impact-absorbing bumpers to the 1974 model year 911 which was easily the new variant’s most distinctive feature.

While an undoubtedly far more elegant solution than the enormous appendages adopted by most high performance manufacturers of the time, the 911’s new bumpers added a significant amount of weight.

Because the 3.0 Carrera RS was not going to be offered in the United States, Porsche made the decision to ditch the G-body impact bumper assemblies in favour of flimsy lightweight single-piece items fashioned from fibreglass.

The redesigned front bumper housed a large rectangular intake for the engine oil cooler flanked by circular brake ducts on either side. The back bumper was adorned only with illumination lights for the licence plate and a pair of small rectangular reflectors slung out underneath.

Fibreglass was also used instead of steel for the front and rear lids, the latter of which came with a new ‘Tea Tray’ spoiler complete with integrated cooling grille and black thermoplastic shroud for the sides and trailing edge.

To save even more weight, thinner gauge steel was used for the doors, the sill covers were left off and ultra thin Glaverbel safety glass was installed at the sides and rear of the car.

Dramatically flared steel fenders were necessary, partly to cover the new wheels but also to enable the RSR version to run massively widened rims (Group 4 regulations dictated the competition version could be up to two-inches wider than the homologated base car).

Instead of chrome, a modern satin black finish was used for the window frames, door handles, exterior mirror and windscreen wipers.

‘Porsche’, ‘Carrera’ and ‘RS’ decals colour matched to the wheel centres were normally adhered to the front lid / bumper, down each flank and on the engine cover respectively.

INTERIOR

In a similar fashion to the M471 Sport-optioned 2.7 Carrera RS, the new three-litre 911 Renn Sport came with fabric Recaro bucket seats, thin felt carpet, rubber floor mats, basic door trim, manual window winders and a simple black headliner.

The rear seats, clock, glovebox door and even the passenger sun visor were deleted. No audio system was originally fitted.

Behind the new-for-1974 three-spoke steering wheel were dials for road and engine speed inboard of which were combination read outs for fuel / oil level and oil temperature / oil pressure. The vacant clock area was simply blanked off.

OPTIONS

Customers could have their 3.0 Carrera RS equipped with practically any of the optional extras offered on the rest of the 1974 model year 911 range. However, most were completed to the lightest possible specification with optimum performance in mind.

The exceptions were the odd examples equipped with electric windows, fully carpeted interiors, rear seats and sunroofs. One car (chassis 9114609027) even came came with a full M472 Touring specification interior.

Some buyers requested equipment like the clock be re-instated and other cars were configured with a two-speaker audio system.

Competition upgrades included a racing rear spoiler without the thermoplastic shroud (not legal for road use), spot lights and a rollcage.

WEIGHT / PERFORMANCE

A typical 3.0 Carrera RS weighed in at between 900kg and 920kg.

Top speed was 152mph and 0-62mph took just 5.3 seconds.

PRODUCTION

3.0 Carrera RS production ran from October 1973 to June 1974.

56 were built in total, six of which were right-hand drive.

The six right-hand drive cars comprised five new examples and the original prototype which was subsequently converted from left-hand drive on behalf of Porsche’s Australian importer.

Afterwards, the Renn Sport moniker was not used on another Porsche road car until its revival for the 964-based 911 Carrera RS of 1991.

COMPETITION HISTORY

Thanks to its 2.7-litre forebear which was produced in sufficient numbers to meet the 1000-car Group 3 production requirement, the 3.0 Carrera RS established an enviable competition record in both circuit racing, hillclimbs and even rallying.

Meanwhile, the Group 4 RSR version went on to become the dominant normally aspirated GT car for the rest of the 1970s and continued to enjoy great success even after the turbocharged 934 arrived during 1976.

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 2.8 / 3.0 Carrera RSR / 73 - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<911 2.8 CARRERA RSR PORTAL
<<<911 2.8 CARRERA RSR FOR SALE

BACKGROUND

Since the late 1950s, Porsche had primarily focused its factory motor sport programmes on Sports and Prototype racing cars. During this period there had been the odd works foray with enhanced 911s, but for the most part the company’s attention had been on purpose-built as opposed to production-based machinery.

That all changed when Ernst Fuhrmann was appointed Porsche Chairman in 1972.

Fuhrmann quickly decided the company should focus more on the 911. As a result, the 1973 season would mark the swansong for the legendary 917 and begin a new era for the 911.

In order to have the most potent 911 racer at its disposal for 1973, Porsche created the 2.7-litre Carrera RS to serve as the base car for a further uprated RSR competition variant.

To homologate the RSR into the premier Group 4 Grand Touring category, a minium of 500 Carrera RS road cars would have to be built within a twelve month timeframe.

Porsche launched the Carrera RS at the Paris Motor Show in October 1972. Following production of the first 500 cars, Group 4 homologation was approved on March 1st 1973.

That season, the resultant 911 Carrera RSR would be campaigned by the factory-supported Martini International, Penske and Brumos teams who normally ran tricked out R-numbered machines often equipped with prototype features. These experimental works cars are covered separately.

Additionally, an off-the-shelf Group 4 911 RSR was placed on sale to anyone with enough cash to buy one (at a price 60% igher than a 2.7 Carrera RS). Nevertheless, uptake was impressive and 49 of these 2.8 / 3.0 Carrera RSR / 73 Customer cars were built during a brief seven month production run starting January 1973.

Buyers could race their RSR in a variety of competitions to include the World Sportscar Championship, the IMSA GT Championship, Trans-Am, the European GT Championship and the Deutsche Rennsport Meisterschaft (DRM). They would go up against a formidable line up of existing Group 4 cars to include the Ferrari 365 GTB/4C, De Tomaso Pantera Gr.4 and Chevrolet Corvette.

CHASSIS

Each RSR was built on a unitary steel bodyshell without any rustproofing or sound deadening. Like the RS, a lightweight floorpan was fitted and the suspension mounts were reinforced.

Additional upgrades on the RSR included solid drivetrain mountings and a front strut brace.

Like every 911 from this era, suspension was via torsion bars and telescopic shocks. The front end used a compact MacPherson strut arrangement with a single lower wishbone. At the rear, semi-trailing arms were installed.

Compared to the RS, the RSR was enhanced with any array of new parts to include stiffer Bilstein dampers and thicker adjustable anti-roll bars. Hard plastic bushings were used for many of the suspension mounts. A needle-type bearing was adopted for the front axle control arm and rear axle strut connection.

To alter the rear trailing arm’s axis of rotation and keep the contact patch of the tyres as flat as possible, the rear axle link was shortened and the pivot point on the cross tube was moved backwards.

The brake system was also suitably uprated, most notably with cross drilled and ventilated 300mm discs and finned four-piston calipers imported from the 917. Brake balance was fully adjustable.

To reduce the dynamic radial variation during dive under braking, the steering knuckle of the front axle was moved upwards on the damper tube.

To achieve an improved adhesion between the hub and rim when braking, Porsche fitted reinforced hubs with a larger diameter, five-screwed driving pins and a central nut with a larger friction surface.

Dunlop shod 15-inch diameter Fuchs alloy wheels measured 9 and 11-inches across (up from 6 and 7-inches respectively). Also present were wheel hub spacers and larger wheel bearings.

Customers could choose from one of five different fuel cells for their RSR. The 62-litre steel tank or 85-litre plastic tank both retained the standard fuel filler cap on the left-hand front fender. Plastic tanks of 100 or 110-litres, or the expensive FIA spec. 120-litre tank, all came with a quick fuel filler cap mounted in a front lid cutaway.

The two battery boxes housed in the front fenders could be removed to improve brake cooling. When this option was taken up, a single battery was mounted in the concealed smuggler’s box.

ENGINE / TRANSMISSION

In the engine bay was a Type 911/72 engine developed from the Type 911/83 motor fitted to the RS base car.

As usual, the new engine was a dry-sumped, air-cooled, all-alloy Flat 6 with single overhead camshaft valve gear.

Thanks to a 2mm bore increase (92mm instead of 90mm), displacement was increased from 2687cc to 2806cc (a gain of 119cc). Stroke length was kept at 70.4mm.

The 2mm bore increase was made possible thanks to cylinder heads that were further apart and Nikasil cylinder linings with aluminium rather than magnesium castings. New forged pistons enabled the compression ratio to be hiked from 8.5:1 to 10.3:1. Connecting rods were specially balanced.

In addition, the RSR motor featured a huge array of hot parts to include four bearing racing camshafts with uprated housings, throttle bodies with intake funnels, rocker arms without adjusting screws, Marelli (later Bosch) twin plug ignition, bigger inlet and exhaust valves, ported cylinder heads, ST valve timing, new Bosch mechanical fuel-injection with an uprated space cam to increase fuel flow, a smaller engine fan and a dual pipe straight through competition exhaust.

The original magnesium alloy crankcase was replaced by a heavier but stronger item fashioned from Silumin alloy.

The crankshaft was imported from the RS albeit lightened, crack-tested and polished and with a new crankshaft damper.

Peak output was 308bhp at 8000rpm and 217lb-ft at 6200rpm.

For comparison, the 2.7 RS pumped out 210bhp at 6300rpm and 188lb-ft at 5100rpm.

Porsche secretly began running a three-litre engine in their R-numbered RSRs in mid April of 1973.

2940cc engines with around 315bhp subsequently began appearing in Customer RSRs from early July.

Later, the proper three-litre Type 911/74 motor also came on stream. It was bored out by an additional 3mm (to 95mm) which gave a displacement of 2993cc and a power output of circa 330bhp.

The existing five-speed 915 gearbox was retained, albeit now with its own oil cooler and an additional pump for pressure lubrication. There was also a lightweight flywheel and a steel disc clutch spring instead of a rubber torsion damper. An uprated limited-slip differential with 80% locking factor was fitted as standard.

BODYWORK

Like the 2.7 RS, the RSR came with body panels that were considerably lighter than on series production 911s.

Thinner steel was for the front and rear wings, the front lid and the roof. The engine cover was fibreglass and featured an integrated Ducktail spoiler. Below was a single piece fibreglass bumper.

A fibreglass single piece bumper was also fitted up front and came with a large rectangular intake to feed an oil cooler. A chin spoiler was soon added as well.

All four wheelarches were more dramatically flared than on the RS.

Rubber retaining straps were added to the front lid.

Like the M471 Sport-optioned RS, thin Glaverbel glass was installed. The rear quarter windows did not open.

‘Carrera’ decals colour matched to the wheel centres were normally adhered down each flank and a matching ‘Porsche’ script was added across the engine lid.

INTERIOR

The RSR’s cockpit was based on that of the M491-optioned RS Sport.

Fabric Recaro buckets were fitted – the driver got a proper racing seat with a six-point harness while the simple passenger-side item was imported from the RS Sport. A fire extinguisher and roll cage were fitted as standard.

Thin black felt was glued in place instead of proper carpet and there was a simple black fabric headliner.

Door trim panels were the same simplified type fitted to the RS Sport and the windows were manually operated.

There were no rear seats and, to save even more weight, even the clock and passenger-side sun vistor were left off.

Instrumentation comprised a 10,000rpm tachometer mounted centrally flanked to the right by a 300kph speedometer, both of which were unique to the RSR. Off to the left were combined read outs for oil pressure / oil temperature and fuel / oil level.

WEIGHT / PERFORMANCE

Porsche managed to trim away 60kg from the 2.7-litre RS H in its transition to RSR trim which put it right on the 900kg Group 4 weight limit. The RSR was also 75kg lighter than an M471 Sport-optioned 2.7-litre RS (975kg) and 175kg less than the M472 Touring version (1075kg).

Depending on gear ratios, 0-62mph could be dispatched in as little as 4.4 seconds. Similarly, top speed could run to 175mph. For comparison, the 2.7 RS had a 153mph top speed and 0-62mph times of 5.4 / 5.7 seconds for the Sport / Touring.

PRODUCTION

Porsche built 49 examples of the RSR Customer / 73 between January and August of 1973.

All 49 were left-hand drive.

The RSR Customer / 73 was replaced by 1974 version based on the revised G Body version.

COMPETITION HISTORY

All but a handful of these cars were pressed into competition duty and the RSR quickly established itself as the dominant Group 4 machine of its era despite a smaller engine than most of its rivals.

Astonishingly, even they were up against Group 5 Prototypes from the likes of Ferrari, Matra and Mirage , two of the R-numbered works RSRs won World Sportscar Championship races outright in 1973: Brumos took victory at the Daytona 24 Hours and Martini International won the Targa Florio.

With eight wins against Ferrari’s two, Porsche easily secured the FIA World Sportscar Championship Cup for GT Cars with 140 points to 40 for the Italians. Chevrolet placed third on 38.

The two American rounds of the 1973 World Sportscar Championship (the Daytona 24 Hours and Watkins Glen 6 Hours) also formed part of that year’s IMSA GT Champiosnhip. Peter Gregg was crowned the ‘73 champion with five wins from ten rounds. His team-mate Hurley Haywood was third (three wins, 75 points) and fellow RSR driver Michael Keyser took the runner up spot for Toad Hall Racing (one win, 126 points).

Despite just two wins out of six for the 911 RSR in Trans-Am, Peter Gregg took the Drivers’ title. He accrued 56 points thanks to one win and three second place finishes. Al Holbert was runner up on 49 points in an R-numbered RSR purchased from Peter Gregg (Brumos).

Back across the Atlantic, the European GT Championship returned for a second season and attracted a fleet of RSRs plus factory-supported De Tomaso Panteras at several rounds. Porsche drivers Claude Ballot-Lena and Claude Schickentanze were tied on 164 points at the end of the year but the Frenchman was crowned champion thanks to his three wins compared to two for Schickentanz.

In the domestic DRM series the privateer Porsche drivers were up against works Group 2 outfits from Ford (Capri RS2600 Lightweight) and BMW Motorsport (E9 CSL). Nevertheless, the new 911 RSR still managed to bag a couple of outright wins but best placed Porsche driver in the final standings was Gunther Steckkonig (fifth on 99).

Text copyright: Supercar Nostalgia
Photo copyright: Supercar Nostalgia & Porsche - https://www.porsche.com

Guide: Ruf Turbo 3.3 - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<TUNER PORTAL

BACKGROUND

Following the premature death of his father in 1974, 24 year old Alois Ruf took the reins of his family’s garage in Pfaffenhausen, Bavaria.

Alois Ruf Snr. had founded Auto Ruf back in 1939. Initially the company focused on general automotive servicing and in 1949 a petrol station was added to the forecourt.

The mid 1950s saw Auto Ruf expand into the tour bus market with the company’s own coachbuilt designs assembled mostly on Mercedes-Benz underpinnings.

Ruf’s association with Porsche began in earnest following the launch of the 911 in 1963. Before long, Alois Ruf had convinced his father to focus on the service and repair of Porsche’s new six cylinder model. This in turn evolved into tuning of 911s as the market for customised cars began to grow during the late 1960s.

In early 1975, work began on the company’s first prototype to coincide with early deliveries of Porsche’s new forced induction 930 (the 911 Turbo).

Starting with a standard three-litre 260bhp four-speed 930, Ruf added lightweight bumpers inspired by the seminal 911 3.0 Carrera RS of 1974. Like the RS, a front-mounted oil cooler was fitted. Inside, the cockpit was kitted out with extended hand-stitched leather supplied by the Roser company in Stuttgart.

Even from this early stage, it was clear that Ruf’s approach to personalisation was more understated than certain other tuners as the company sought to strike the perfect balance between elegance and sportiness.

Over the next 18 months, Ruf set about developing a further enhanced 911 Turbo with a bigger engine and uprated gearbox. The resultant Ruf Turbo 3.3 arrived in early 1977. It boasted an engine bored out by 249cc to 3.3-litres which yielded 43bhp more than the standard car. Even more significantly, the Ruf Turbo 3.3 came with a five instead of four-speed gearbox which transformed the 930’s performance.

Despite having been priced at a circa 50% premium over a standard 930, orders for complete Ruf cars began to come in at the rate of around five per year. Each vehicle was built with a mix of genuine Porsche and special Ruf parts and given a new chassis number.

ENGINE / TRANSMISSION

Although its handsomely configured body and high end interior were undoubtedly important attributes, what really set the Ruf Turbo 3.3 apart was its trick engine and gearbox combination.

Production of the standard 930 had begun in February 1975 with each car powered by an air-cooled all-alloy three-litre Flat 6 with dry-sump lubrication, single overhead camshafts and two valves per cylinder. Forged alloy pistons were fitted along with Nikasil-lined barrels and a lightweight aluminium crankcase.

From the factory, the single KKK 3 LDZ turbo ran at 0.8 bar with a water-to-air intercooler and 6.5:1 compression ratio. Fuel-injection was via the familiar Bosch K-Jetronic system.

Although Porsche would go on to release an enlarged 3299cc engine in September 1977, for now the crankshaft used on the factory 3.3-litre engine did not exist. Accordingly, Ruf increased the displacement of its 3.3-litre motor by enlarging the cylinder bores from 95mm to 98.9mm while stroke was kept at 70.4mm. This gave an overall displacement of 3243cc compared to 2994cc for the standard 930.

Housed behind the rectangular RS-style radiator in the front bumper assembly were a trio of oil coolers for the engine, gearbox and air-conditioning systems.

A dual instead of single outlet free flow exhaust was added to more quickly discharge gasses.

The turbocharger, compression ratio and fuel-injection system were carried over with their factory settings.

In this configuration, the Ruf Turbo 3.3 pumped out 303bhp compared to 260bhp at an identical 5500rpm to the regular 930.

The torque rating went from 253lb-ft to 303lb-ft, once again at an unchanged 4000rpm.

For the 915-based five-speed gearbox, Ruf used parts from the Porsche 934 / 935 racing catalogue so it could be adapted for the torque of the turbocharged engine. Upgrades included a specially treated gear spray lubrication, a thermostatically controlled oil cooling system (via the front mounted cooler), a short throw shifter, new pressure plate, new clutch disc and new clutch cable.

Shorter ratios were used on first through third gears with standard ratios on fourth and fifth.

A limited-slip differential with 60% locking factor was fitted as standard.

Ruf created space for the extended transmission housing by doing away with the vibration damper between the engine and transmission which was something the factory did not want to do for reasons of comfort. This inevitably resulted in more cockpit noise, especially at lower speeds, but was a small price to pay for the much-improved performance.

CHASSIS

The starting point for each Turbo 3.3 was a standard steel 930-type monocoque bodyshell.

To this, Ruf added uprated gas-filled Bilstein dampers and dropped the ride height. Suspension settings were typically mid-way between production and competition specification. Wheel spacers were added to provide a slightly wider track.

Standard 16-inch diameter Fuchs wheels were normally retained (7-inches wide front and 8-inches wide rear). Pirelli P7s were Ruf’s preferred rubber.

Otherwise, the rest of the specification was carried over from the regular 930.

The front suspension layout comprised MacPherson struts with lower wishbones, longitudinal torsion bars and anti-dive geometry. Out back were semi-trailing arms with anti-squat. Anti-roll bars were fitted at either end.

Dual circuit brakes ran separate systems for each axle. Discs and calipers were sourced from the 2.7-litre Carrera with 282.5mm and 290mm discs installed front to rear respectively.

Underneath the front lid was a standard 80-litre fuel tank.

BODYWORK

Cosmetically, Ruf normally added simplified fibreglass bumpers in the style of the legendary 911 3.0 Carrera RS which saved a considerable amount of weight compared to the original steel impact-absorbing units.

The front bumper assembly housed a large rectangular intake that fed fresh air to the aforementioned engine, transmission and air-conditioning oil coolers. Circular brake ducts were cut away from either side and the 930’s fog lights were discarded.

The rest of the specification was pure 930, a design characterised by its massively flared fenders compared to a normally aspirated 911 of the period.

OEM body panels were fashioned entirely from steel.

Further customisation could be carried out via Ruf’s long list of optional extras.

INTERIOR

Although the 930 had been conceived as a homologation special to pave the way for Porsche’s turbocharged 934 and 935 racing cars, it was pitched as a high end model unlike the pared down Carrera RS models from the early 1970s.

This very much suited Ruf’s clientele who typically wanted their cars equipped to an even more luxurious specification and routinely selected from the wide array of cockpit options on offer.

930s automatically left the factory with half leather sports seats that featured tartan fabric centres and door panels trimmed to match.

A small diameter leather-rimmed three-spoke steering wheel, extra sound insulation and deep pile carpet were other special 930 items.

An 8000rpm rev counter replaced the 7000rpm tach fitted to regular 911s, but a boost gauge was not initially fitted to production cars. Off to the left of the rev counter were combined read outs for oil pressure / oil temperature and oil level / fuel. To the right was a 300kmh / 180mph speedo and a clock.

Standard equipment included electric windows, a four-speaker stereo with front fender-mounted electric antenna, a rear wiper, headlight washers and fog lights.

OPTIONS

Ruf offered the Turbo 3.3 in both narrow or wide-bodied configurations.

Other options included body coloured trim (for the window frames, door handles, door frames and decorative strips), body coloured wheel centres, heated exterior mirrors and custom damper settings. The standard impact-absorbing bumpers could be retained if desired.

It was inside that Ruf’s customers were really able to go to town.

Upholstery could be specified in full leather (in mono or two-tone) or leather with fabric inlays. The extended leather package included a perforated headliner, a hand-stitched leather dashboard, leather armrests plus all metal and plastic parts covered in matching hide.

Ruf could also install Recaro sports seats, central locking, interior footwell lighting, additional instrumentation, a centre console and an array of high end audio systems.

WEIGHT / PERFORMANCE

Thanks to the removal of the heavy impact-absorbing bumper assemblies in exchange for lightweight fibreglass RS-style items, a Ruf Turbo 3.3 sans air-conditioning and elaborate audio system tipped the scales at 95kg less than a standard 930 (1100kg as opposed to 1195kg).

In narrow body trim, top speed was 176mph which dropped to 165mph for the wide-body version. For comparison, the standard 930 had a 154mph top speed.

Because the five-speed gearbox reduced the wide spread of power delivery over the standard four-speed version, acceleration times were much-improved and it was considerably easier to keep the engine on boost.

In terms of the benchmark 0-62mph time, the Ruf car posted a figure of just 5.2 seconds compared to 5.7 seconds for the production 930.

PRODUCTION CHANGES

Although Porsche introduced their own 3.3-litre 930 in September 1977, Ruf still did good business uprating existing three-litre cars for their customers. There was also plenty of demand for factory 3.3-litre 930s with Ruf’s five-speed gearbox.

In 1978, Ruf began to offer their turbocharged model with similar style bumpers to the new SCR. The impact absorbing elements were retained at either end while up front were the aforementioned RS-style intakes complete with a jutting chin spoiler. Koni dampers were also added to the options list along with a four outlet exhaust.

In 1981, Ruf moved on to a dog-leg gearbox based on the four-speed unit from the 930 to which an additional gear was added. Cabriolet and Targa body styles were now offered as well.

That year, Ruf received certification from the German Federal Motor Vehicles Bureau as manufacturer in its own right. This was done because Porsche insisted Ruf be responsible for the safety of its cars that were operating at performance levels well above the originals.

END OF PRODUCTION

1983 saw Ruf replace the Turbo 3.3 with their new 374bhp BTR.

By this time it is believed that around 15-25 turbocharged cars had been converted by Ruf to varying specifications.

Text copyright: Supercar Nostalgia
Photo copyright: Ruf - https://www.ruf-automobile.de/en/ & Auto Motor und Sport - https://www.auto-motor-und-sport.de/

Guide: Porsche 911 2.8 / 3.0 Carrera RSR / 73 Werks - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<911 2.8 / 3.0 CARRERA RSR ‘WERKS’ PORTAL
<<<911 2.8 CARRERA RSR FOR SALE

BACKGROUND

Having been appointed Porsche chairman in August 1972, Dr Ernst Fuhrmann immediately decided the 917 programme had become excessively expensive and too detached from the firm’s road car offerings.

Fuhrmann felt the company should re-focus its competition programme to vehicles that more closely aligned with those available in Porsche showrooms.

Accordingly, the 917 project would be wound down at the end of 1973; as a result, the new and astonishingly powerful 917/30 was given just one season in the limelight.

Thereafter, attention would turn exclusively to the 911 that, in motor sport terms, had always played second fiddle to the factory’s Sports Prototypes.

Since 1970, the premier category for production-based GT racing cars was Group 4. To qualify for Group 4, a manufacturer first had to produce 500 identical road-going base cars upon which a more extreme competition variant could be derived.

Porsche had already built small numbers of ST 911s for the Group 4 era, but works participation had been fleeting and limited to a handful of key events such as the Monte Carlo Rally and Tour de France.

As had been the case with the ST, Porsche could have used the standard road-going 911 to homologate a racing variant. However, to give the firm every chance of success, they conceived the fabled 2.7-litre Carrera RS homologation special which was launched at the Paris Motor Show in October 1972.

In turn, the 2.7 Carrera RS spawned a racing variant that was sold to customers: the 2.8 Carrera RSR.

Alongside the 2.8 Carrera RSR, which was available to anyone with sufficient funds, the works equipe (and a couple of Porsche’s trusted satellite teams in the USA) campaigned a small series of increasingly experimental RSRs designed to push the 911 concept to its absolute limit.

These tricked out factory specials gradually began to incorporate features not permitted on the 2.8 Carrera RSR which ultimately forced them into the Group 5 category for purpose-built Sports Prototypes such as those from Ferrari, Matra, Mirage and Alfa Romeo.

EARLY PROTOTYPES

The RSR story began with a pair of cars that the factory rebuilt with new bodyshells and re-numbered.

Chassis 9112300769 was originally delivered to privateer driver, Sobieslaw Zasada, for 1972. Zasada had only used the car in a couple of events before he crashed it heavily on the Polish Rally in July of that year. Zasada returned the car to Porsche and took delivery of a replacement. Meanwhile, the factory rebuilt 9112300769 around a new shell and re-numbered it as 9113600001 (‘0001’).

Chassis 9112300841 was an unused bodyshell that the factory renumbered as 9113600002 (‘0002’).

These two cars subsequently served as development mules for the forthcoming Carrera RSR.

1972 ZELTWEG 1000KM

As racing was the primary consideration, one of the prototypes was quickly wheeled out to assess its capabilities on track.

In late June, 0002 was trucked to Austria for the Zeltweg 1000km (the penultimate round of that year’s World Sportscar Championship).

The Indian Red car was allocated to factory drivers, Gunter Steckkonig and Bjorn Waldegaard. To avoid attracting too much attention it was discretely entered under the auspices of long-standing Porsche customer, Paul Ernst Strahle.

As the car had not yet been homologated into Group 4, 0002 had to run in the three-litre Group 5 Sports category. However, this enabled Porsche to try out several experimental features of the type that would be adopted for 1973.

Listed in the race entry as a 911 S 2.7, chassis 0002 was fitted with an engine said to be “somewhere between 2.7 and 3-litres” and with an output of “around 290bhp”.

Other special equipment included the same cross-drilled and ventilated anti-lock brakes introduced on the Martini 917 of Helmut Marko / Gerard Larrousse at the same race a year earlier.

The front suspension had also been modified and the rear wheels were widened to 11-inches (up from 9-inches on the ‘72 911 ST).

Externally, 0002 stood out on account of its custom front apron, flared fenders and a distinctive boxed-in Ducktail rear spoiler which also incorporated an adjustable trailing flap.

0002 qualified 18th on the grid, one place ahead of the fastest bona fide Group 4 GT entry: the 5.7-litre V8-powered De Tomaso Pantera Gr.4 of Alex Janda and Hans Schulze-Schwering.

In the race, 0002 proved significantly quicker than the 285bhp Kremer Racing 911 ST of John Fitzpatrick and Erwin Kremer. Steckkonig and Waldegaard ultimately claimed tenth place overall and finished ten laps clear of their closest GT class contender.

FURTHER DEVELOPMENT

After the Zeltweg race, 0002 returned to Germany where, alongside 0001, it resumed its role as a development mule.

In early November 1972, Porsche completed the first brace of their special R-numbered RSRs: 9113600019 (also known as R1) and 9113600020 (R2). They were subsequently followed by another six R-numbered examples that would be campaigned throughout 1973 (R3 through R8).

These tricked out factory specials were continually developed during the ‘73 season and equipped with all the latest competition parts from the Weissach racing department.

CHASSIS

Each RSR was built on a unitary steel bodyshell without any rustproofing or sound deadening material. Like the RS, a lightweight floorpan was fitted and the suspension mounts were reinforced.

Additional upgrades fitted to the RSR included solid drivetrain mountings and a front strut brace.

As ususal, suspension was via torsion bars and telescopic shocks. The front end used a compact MacPherson strut arrangement with a single lower wishbone. At the rear, semi-trailing arms were installed.

Compared to the RS, the RSR was enhanced with any array of new parts to include stiffer Bilstein dampers and thicker adjustable anti-roll bars. Hard plastic bushings were used for many of the suspension mounts. A needle-type bearing design was adopted for the front axle control arm and the rear axle strut connection.

To alter the rear trailing arm’s axis of rotation and keep the contact patch of the tyres as flat as possible, the rear axle link was shortened and the pivot point on the cross tube was moved backwards.

The brake system was also suitably uprated, most notably with cross drilled and ventilated discs and finned four-piston calipers imported from the 917. Brake balance was fully adjustable.

To reduce the dynamic radial variation during dive under braking, the steering knuckle of the front axle was moved upwards on the damper tube.

To achieve an improved adhesion between the hub and rim when braking, Porsche fitted reinforced hubs with a larger diameter plus five-screwed driving pins and a central nut with a larger friction surface.

Dunlop shod 15-inch diameter Fuchs alloy wheels of 9 and 11-inches were used (up from 6 and 7-inches respectively). Also present were wheel hub spacers and larger wheel bearings.

Customers could choose from one of five different fuel cells for their RSR. A 62-litre steel tank or 85-litre plastic tank both retained the standard fuel filler cap on the left-hand front fender. Plastic tanks of 100 or 110-litres, or the expensive FIA spec. 120-litre tank, all came with a quick fuel filler cap mounted in a front lid cutaway.

The two battery boxes housed in the front fenders could be removed to improve brake cooling. When this option was taken up, a single battery was mounted in the concealed smuggler’s box.

ENGINE / TRANSMISSION

Three different engines were used by the factory during the 1973 season. Each was developed out of the Type 911/83 motor fitted to the RS base car and was a dry-sumped, air-cooled, all-alloy Flat 6 with single overhead camshaft valve gear.

First to arrive was the Type 911/72 power unit which, thanks to a 2mm bore increase (92mm instead of 90mm), displaced 2806cc as opposed to 2687cc (a gain of 119cc). Stroke length was kept at 70.4mm.

The 2mm bore increase was made possible thanks to cylinder heads that were further apart and Nikasil cylinder linings with aluminium rather than magnesium castings. New forged pistons enabled the compression ratio to be hiked from 8.5:1 to 10.3:1. The connecting rods were specially balanced.

In addition, the RSR motor featured a huge array of hot parts to include four bearing racing camshafts with uprated housings, throttle bodies with intake funnels, rocker arms without adjusting screws, Marelli (later Bosch) twin plug ignition, bigger inlet and exhaust valves, ported cylinder heads, ST valve timing, new Bosch mechanical fuel-injection with an uprated space cam to increase fuel flow, a smaller engine fan and a dual pipe straight through competition exhaust system.

The original magnesium alloy crankcase was replaced by a heavier but stronger item fashioned from Silumin alloy.

The crankshaft was imported from the RS albeit lightened, crack-tested and polished and with a new crankshaft damper.

Peak output was 308bhp at 8000rpm and 217lb-ft at 6200rpm.

For comparison, the 2.7 RS pumped out 210bhp at 6300rpm and 188lb-ft at 5100rpm.

By April of 1973, Porsche had developed a three-litre Type 911/74 motor that had been bored out by an additional 3mm (to 95mm) which gave a displacement of 2993cc. Power output was now 315bhp.

For the Le Mans 24 Hours in June, an even more highly tuned Type 911/75 motor was on stream with 330bhp.

The existing five-speed 915 gearbox was always retained, albeit now with its own oil cooler and an additional pump for pressure lubrication. There was also a lightweight flywheel and a steel disc clutch spring instead of a rubber torsion damper. An uprated limited-slip differential with 80% locking factor was fitted as standard.

BODYWORK

Like the 2.7 RS, the RSR came with body panels that were considerably lighter than on series production 911s.

Thinner steel was used for the front and rear wings, the front lid and the roof. The engine cover was fibreglass and featured an integrated Ducktail spoiler. Below was a single piece fibreglass bumper.

A fibreglass single piece apron was also fitted up front and came with a large rectangular intake to feed an oil cooler. A chin spoiler was soon added as well.

All four wheelarches were more dramatically flared than on the RS.

Rubber retaining straps were added to the front lid.

Like the M471 Sport-optioned RS, thin Glaverbel glass was installed. The rear quarter windows did not open.

‘Carrera’ decals were adhered down each flank and a matching ‘Porsche’ script was added across the engine lid.

INTERIOR

The RSR’s cockpit was based on that of the M491-optioned RS Sport.

Fabric Recaro buckets were fitted – the driver got a proper racing seat with a six-point harness while the simple passenger-side item was imported from the RS Sport. A fire extinguisher and roll cage were fitted as standard.

Thin black felt was glued in place instead of proper carpet and there was a simple black headliner.

Door trim panels were the same basic type fitted to the RS Sport and the windows were manually operated.

There were no rear seats and to save even more weight the clock and passenger-side sun visor were absent.

Instrumentation comprised a 10,000rpm tachometer mounted centrally flanked to the right by a 300kph speedometer (both of which were unique to the RSR). Off to the left were combined read outs for oil pressure / oil temperature and fuel / oil level.

WEIGHT / PERFORMANCE

The first RSRs weighed in at the homologated 900kg. However, by the end of the season this had come down to around 830kg thanks to the use of titaniuam and fibreglass parts.

Depending on gear ratios, 0-62mph could be hit in a little over 4 seconds. With the tallest ratio installed, a top speed in excess of 180mph was possible.

1972 TOUR DE CORSE

Ahead of the ‘73 season, a series of tests were carried out at Paul Ricard. Chassis R1 and R2 were also wheeled out for a preparatory outing on the 1972 Tour de Corse. At this stage, the suspension was still to more or less RS specification.

The 687km Tour de Corse was round 23 of the 1972 European Rally Championship. It took place over November 4th and 5th and comprised 24 stages, all of which were on tarmac.

R1 arrived in Corsica with a 2.8-litre engine and was allocated to Bjorn Waldegaard / Hans Thorszelius.

R2 had a 3-litre engine and was used by Gerard Larrousse / Christian Delferier.

For this event, both were finished in a white and red striped Marlboro livery and appeared under a Porsche KG entry.

Significantly, the 1972 Tour de Corse marked the debut for Lancia’s prototype Stratos (which was similarly backed by Marlboro). Also in attendance was the works Alpine Renault team with no less than five A110 1800s.

Unfortunately, neither Porsche made it to the end: Larrousse went out with transmission failure while Waldegard crashed out having set a blistering early pace.

Victory went to the works Alpine A110 of Jean-Claude Andruet and Michele Espinosi-Petit who led from start to finish.

1973 SEASON

Porsche retained 0001, 0002, R1 and R2 for the 1973 season. New cars numbered R3 through R8 were also built up.

The un-raced 0001 continued to act as a test mule prior to being sold off in February ‘74 (by which time it was surplus to requirements).

0002 (as raced at Zeltweg) was rebuilt as a Martini team car then used for promotion and development purposes. It was also drafted in to compete at one event (the ‘73 Targa Florio) after another RSR (chassis R8) was destroyed in practice.

R1 did not appear again following Waldegaard’s accident on the ‘72 Tour de Corse but was used for testing.

R2 was also used for R&D and then rebuilt as a Martini team car for 1973.

Group 4 homologation was approved on March 1st.

European legs of the 1973 World Sportscar Championship would be managed by the works Martini Racing team while, in the USA, that responsibility fell to Brumos and Penske Racing.

1973 DAYTONA 24 HOURS

The 1973 World Sportscar Championship kicked off with the Daytona 24 Hours that took place over the weekend of February 3rd and 4th.

A pair of the new works-supported RSRs were in attendance: R3 was entered for Mark Donohue / George Follmer and appeared in a dark blue and yellow livery (the colours of Penske Racing’s sponsor, the Sun Oil Company). R4 was on hand for Peter Gregg / Hurley Haywood and was painted in the Brumos colours of white with thick red and blue stripes.

As the RSR had not yet been homologated into the Group 4 GT category, both cars ran in the Group 5 Prototype class where they would be up against Gulf-backed M6 Mirages, a lone Matra MS670, Scuderia Filipinetti’s Gitanes-backed Lola T282 and a couple of old Porsche 908s. Unfortunately, a lack of prize money meant Ferrari stayed at home with their latest iteration of the 312 PB.

Gregg / Haywood qualified eighth in the Brumos RSR and Donohue / Follmer lined up twelfth in their Penske machine.

Although Donohue had to make an unscheduled stop to address an out-of-balance wheel, both cars ran strongly in the early stages with the Brumos machine fifth and the Penske entry sixth.

The first of the more highly fancied entries to drop out was the much delayed Bell / Ganley Mirage which disappeared after 179 laps with clutch trouble.

Shortly after the five hour mark, the Matra of Cevert / Beltoise took lead from the Hailwood / Watson Mirage which came in for a clutch change. At the same time, the Joest Porsche 908/03 of Joest / Casoni (which should have been promoted to second) came in for a 90 minute stop to rectify a leaking fuel tank.

This meant the two 911s suddenly found themselves in second and third, twelve laps behind the Matra which was being very steadily driven at around same pace as the Porsches.

Later in the evening, Donohue briefly moved the Penske RSR into second while Haywood was black flagged in the Brumos entry for a faulty headlight. However, when the Penske car came in for fuel, the Brumos 911 re-took second spot. At this stage (around one third distance), the two Porsches were nine laps behind the Matra which had made a leisurely stop for fresh tyres and brake pads.

It looked like Matra had the race pretty much sewn up, but shortly after midnight, Francois Cevert rolled to a halt with a connecting rod sticking out the side of the block. This left Penske and Brumos holding the first two positions in the so far faultless Carreras. Third placed Arturo Merzario was 18 laps behind in his Group 4 Ferrari 365 GTB/4C.

By this time, the Bell / Ganley Mirage had been retired following a second clutch repair which meant the team’s hopes rested with Hailwood / Watson. The Joest 908/03 was also out with gearbox issues.

At around 5am, the Penske machine pitted with a three-quarter lap lead over Brumos, but soon after it rejoined an ominous trail of smoke began to emerge. The blue Porsche was quickly brought back into the pits where it was diagnosed with a holed piston and retired.

By 9am, the 53 car field that started the race was down to just 17 runners. R4 had by this time developed a large crack in its windscreen, however, with a 35 lap lead, the eight minute stop to fit new glass proved inconsequential.

Peter Gregg and Hurley Haywood ultimately went on to win by 22 laps.

After its historic victory, R4 was retired from competition duty. Penske sold R3 to Al Holbert who used it to contest the 1973 Trans-Am series.

Brumos went on to race a customer RSR in the IMSA and Trans-Am series for the rest of 1973 (chassis 9113600727).

1973 MARTINI PRESS CONFERENCE

On March 5th, Martini Racing held its annual Press Conference at the Pavilion d’Armenonville in the Bois de Boulogne. The event, hosted by Count Rossi, marked the announcement of ex-John Wyer Automotive Engineering manager, David Yorke, as team boss.

Resplendent in its new Martini colour scheme, chassis 0002 was presented alongside one of the team’s 917s from 1971. A two-car programme was announced for the European legs of the ‘73 World Championship.

1973 VALLELUNGA 6 HOURS

Round two of the 1973 World Sportscar Championship was the Vallelunga 6 Hours on March 25th.

As expected, Martini Racing arrived with two works-supported cars: chassis R5 for Gijs van Lennep / Hebert Muller and R6 for George Follmer / Willi Kauhsen. With Group 4 homologation having been approved, both cars ran in the GT class which meant they did not have the benefit of some of the improved suspension and engine parts seen at Daytona.

The Martini squad would be up against very limited opposition in the shape of a solitary customer RSR run by Porsche Club Romand, a pair of Panteras and a Porsche 914/6.

None of the works drivers were particularly happy with the way the cars were handling, but new uprights and other suspension upgrades were in the pipeline once these parts had been homologated on April 1st.

A timing error saw van Lennep / Muller given a bogus qualifying time which meant it lined up in 15th having supposedly gone nearly six seconds quicker than Follmer / Kauhsen who started 21st. The only other GT class car to qualify was the customer RSR of Cheneviere / Zbinden in 20th.

While the customer RSR retired shortly before mid distance with a faulty clutch pedal, the Martini cars had a race long battle with one another. This was eventually decided in favour of Follmer / Kauhsen when the van Lennep / Muller entry had to make a last minute stop to change a front tyre which let the sister car through.

Follmer / Kauhsen finished seventh overall and van Lennep / Muller were eighth. As the only GT cars still running, Martini Racing claimed first and second in class.

Outright victory went to the Mastra MS670B of Pescarolo / Larrousse / Cevert.

1973 LE MANS TEST

Next up for Martini Racing was the annual Le Mans Test which took place over the weekend of March 31st / April 1st.

The two factory Porsches went extremely well with Muller posting fourth fastest time in R6 and van Lennep going fifth quickest in R2. Both cars ran in the Group 5 category as they arrived with several as-yet un-homologated parts. Impressively, Muller’s best lap was over seven seconds quicker than the Greder Racing Team Chevrolet Corvette that had topped the Grand Touring category.

The Matra MS670B of Beltoise / Larrousse went fastest overall. Ferrari were prevented from attending owing to a strike at the factory.

1973 LE MANS 4 HOURS

In an attempt to attract participants to the test and help justify opening the track, the Le Mans governing body organised a four hour race for Sunday afternoon.

Not all the teams that attended the test took part; the fastest car in qualifying had been the Archambaud Racing Lola T292 of Larrousse / Bayard, but as a result of subsequent engine trouble it had to start at the back of the field.

This left van Lennep / Muller on pole in R2 while Manfred Schurti / Helmuth Koiningg were just behind in R6.

Both Martini Porsches were overtaken by the fast-starting Lola during the early stages of the race and van Lennep had a good battle with Henri Greder’s Corvette until both cars pitted for a driver change. Soon afterwards the engine in the Larrousse / Bayard Lola overheated and it was pushed into retirement.

Muller thus inherited a lead he would retain until then end. R2 took the win from the Touroul / Rouget Porsche 910 while Andruet / Wollek secured the final podium spot in their Pozzi Ferrari 365 GTB/4C. Schurti / Koinigg took fourth after a steady run in R6.

1973 DIJON 1000KM

Martini Racing returned to World Sportscar Championship action with a single car entry for van Lennep / Muller the Dijon 1000km on April 15th (chassis R5).

Three other GT cars completed the small but high quality entry: a pair of customer RSRs from Kremer and Porsche Club Romand plus a De Tomaso Pantera from Ecurie Franco Britannic.

Unlike the customer versions, R5 appeared at Dijon with modified suspension to include titanium springs plus a newly homologated trailing link set up that helped keep all four wheels planted firmly on the ground.

In R5’s engine bay was rumoured to be a three-litre power unit, but Porsche were highly secretive on the subject. Kremer’s John Fitzpatrick claimed there was no way his car had the same motor as the Martini entry and this was born out in qualifying when R5 went 2.3 seconds quicker than the best customer RSR.

Muller / Van Lennep started from 15th, Cheneviere / Zbinden were 16th for Porsche Club Romand, Fitzpatrick / Keller lined up 18th for Kremer and the Pantera qualified 19th.

In the race, the only trouble for the Martini car was an unscheduled rear tyre change after excessive oversteer had worn it flat. Muller / van Lennep finished three laps ahead of the Kremer RSR in ninth overall.

Pescarolo / Larrousse took the outright win for Matra ahead of the Ickx / Redman Ferrari.

1973 MONZA 1000KM

Ten days later, round four of the World Championship took place with a 1000km race at Monza (April 25th).

After suspicions at Dijon, Porsche confirmed both their cars in attendance were running engines that had been bored out to three-litres. They also featured the same rear suspension upgrades used in France which was a point of consternation for one of the Italian competitors who claimed the changes in question had not been homologated.

The organisers ultimately decided to put the Martini Porsches in the Group 5 Prototype class and they were forced to re-qualify on the second day of practice.

As a result, the Martini crew decided to take advantage of the unrestricted modifcations permitted in Group 5 and hurriedly riveted additional aluminium spoiler panels in place either side of the original Ducktail. These extra winglets subsequently became known as Mary Stuart collars.

The two cars taken to Italy were R6 for van Lennep / Muller and R8 for Follmer / Schurti.

Follmer / Schurti qualified fastest of the production-based cars in 24th while van Lennep / Muller lined up 34th.

Unfortunately, neither of the Martini entries finished the race. Follmer was an early retirement after just 19 laps when he brought R8 into the pits having over-revved the engine during a missed gear change. The sister car of van Lennep / Muller went out on the 62nd of 174 laps with a blown piston.

Victory in the Group 5 class went to the Ferrari 312 PB of Ickx / Redman and the GT category was won by the customer RSR of Schickentanz / Kremer which finished eighth overall.

1973 SPA 1000KM

Round five of the ‘73 World Sportscar Championship was the Spa 1000km which took place on May 6th.

Martini Racing took two cars to Belgium: R5 was entered for the Group 4 GT category and originally allocated to van Lennep / Muller while the big-winged R6 would run in the Group 5 Prototype class for Follmer / Joest.

However, mid-way through practice, Muller and van Lennep decided they wanted to race the Group 5 car which meant Follmer / Joest were relegated to the Group 4 entry.

An unhappy Follmer did subsequently manage to get R5 round with third quickest time in the GT class (20th overall – behind a pair of Kremer customer RSRs), but he said the car’s handling scared him to death.

Muller and van Lennep qualified 13th in the Group 5 Martini entry and had a solid run to finish fifth overall. The M6 Mirages of Bell / Hailwood and Hailwood / Ganley finished first and second followed by the Matra MS670B of Pescarolo / Larrousse / Amon.

In the Group 4 category, Fommer and Joest took a lucky win after the Schickentanz / Fitzpatrick customer RSR went out with a blown engine just before the end. Follmer had actually been leading the GT class when he handed over to Joest, but the German driver proceed to lose nine seconds per lap which meant Follmer was third when he got back in for his second stint. The Martini car had looked to have no chance of a win until Kremer’s lead RSR blew up.

1973 TARGA FLORIO

May 13th saw the final running of the Targa Florio at World Sportscar Championship level. In future, the epic contest which took place around a spectacular 72km Sicilian road course was deemed too unsafe for the World Championship organisers.

Martini Racing took four cars to Italy in the hope of scoring a major upset on a track that was arguably better suited to the 911 than top flight Prototype racing cars. All of the Martini 911s ran in the Group 5 class with the latest pistons installed. Also running in the same category was a Marlboro-backed works Stratos prototype.

R6 was allocated to the number one pairing of Muller / van Lennep, R2 to Leo Kinnunen / Claude Haldi and R8 to Gunther Steckkonig / Giulio Pucci. Chassis 0002 went along as a spare in the event of any mishaps around the unforgiving circuit.

Just such an incident occurred during the Friday evening practice session when Pucci lost it in a big way at the top of Campofelice and slammed sideways into a tree. Fortunately, the impact was on the passenger side of the car, otherwise Pucci would almost certainly have been killed.

With its bodyshell crumpled beyond repair, R8 was written off.

In its place, 0002 was hastily prepared which included the installation of R8’s engine.

Muller / van Lennep went fifth quickest in practice behind the 312 PB Ferraris and 33/TT/3 Alfa Romeos. The Stratos of Munari / Andruet posted sixth quickest time while Steckkonig / Pucci had gone eighth quickest and Kinnunen / Haldi 15th. One of the two Group 5 Alfas failed to start after the car driven by Clay Regazzoni somersaulted down the mountainside and landed upside down in a field, miraculously without injury to the driver.

The race got underway shortly after 9am with cars sent off in 30 second intervals.

At the end of lap one, Muller was fourth behind the two Ferraris and sole remaining Alfa. However, lap two saw the Ferraris of Merzario and Ickx drop out with transmission failure and crash damage respectively. At this point, it looked like Alfa Romeo had the race in the bag if Stommelen and de Adamich could keep their car on the road.

However, after Stommelen handed over to de Adamich at the end of lap three, a local driver in a Lancia Fulvia failed to see the fast approaching Alfa and forced it off the tarmac. With his suspension too deranged to continue, de Adamich was faced with a long walk back to the pits.

This left Muller and van Lennep at the head of the field with a decent-sized gap over the Stratos which had been delayed by stops for attention to a broken seat.

The Porsche drivers completed the remaining 500km at a steady pace to win by a little over six minutes from the Lancia. Kinnunen / Haldi were another twelve minutes down the road in third and Steckkonig / Pucci claimed sixth following a couple of minor delays.

1973 NURBURGRING 1000KM

Martini Racing reverted to a two-car entry for Porsche’s home race: the Nurburgring 1000km on May 27th (round seven).

On this occasion, chassis R7 was entered for Muller / van Lennep to contest the Group 5 class while R5 ran in the Group 4 category with Follmer / Kauhsen.

R7 was a brand new RSR with a re-shaped back end designed to take massive new centre-lock wheels with titanium hubs. The rear wheels went up to 15-inches wide while the fronts came in at 10.5-inches. Thanks to an all-fibreglass body, R7 was now considerably lighter than a Group 4 RSR.

Muller / van Lennep put R7 15th on the grid while Follmer / Kauhsen lined up 16th. However, R5’s lap was widely thought to be the result of a timing error as it went over eleven seconds quicker than the next best GT car (a customer RSR run by Kremer).

The 44 lap race got underway at 11am. Gijs van Lennep initially dropped behind a series of Group 2 saloon cars but had managed to repass them all by lap three.

Meanwhile, Follmer had established a healthy GT class lead in R5, but his race ended abruptly on lap seven when the car suddenly went sideways without warning at the Adenau Bridge. R5 planted itself firmly into the barrier and sustained quite serious damage to the chassis.

By this time, van Lennep had moved R7 into seventh.

Subsequent retirements for the de Adamich / Stommelen Alfa Romeo 33/TT/12 and the Cevert / Beltoise Matra MS670B saw the RSR rise to fifth by the time the chequered flag fell.

Victory went to the Ferrari 312 PB of Ickx / Redman with the sister car of Pace / Merzario second.

1973 LE MANS 24 HOURS

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Undoubtedly the biggest sports car race of 1973 was the Le Mans 24 Hours which took place over the weekend of June 9th and 10th. For this event, round eight of the World Championship, there were three factory RSRs on hand.

One was the lightweight wide-bodied R7 (for Muller / van Lennep) as raced at the Nurburgring two weeks earlier. Chassis R6 (for Joest / Haldi) arrived at la Sarthe in a similar configuration to R7 having been comprehensively uprated since its last appearance (when it won the Targa Florio). Both cars ran in the Group 5 class with new 12-inch rears wheels and the latest 330bhp Type 911/75 engines.

The other works-assisted RSR was chassis R2 which contested the Group 4 Grand Touring category. This yellow and green car appeared under a Porsche Sonauto BP Racing banner for Peter Gregg / Guy Chasseuil. Sonauto was Porsche’s French distributor.

Muller / van Lennep qualified 18th with the sister car of Joest / Haldi just behind in 19th.

The Group 4 entry of Gregg / Chasseuil started from 36th which was second fastest of the under three-litre GT cars behind the customer RSR of Loos / Barth (which started 32nd).

A 4pm rolling start saw most of the field blast away without incident. However, Joest’s Group 5 RSR seemed to be making very slow progress and R6 was brought into the pits at the end of its opening tour for attention to the gearbox.

At the three hour mark, van Lennep was in a battle for seventh position with the two-litre Group 5 Chevron B23 of Pierre Maublanc. Joest had got the sister Martini car back up to 30th following its lengthy stop while Peter Gregg had moved the yellow and green Sonauto entry up to 15th.

By midnight, the 55 car field was much depleted. The Martini RSR of Muller / van Lennep was going like a train in eighth and the Sonauto machine of Gregg / Chasseuil had moved into eleventh. Unfortunately, the other Martini entry of Joest / Haldi had retired shortly before 10pm owing to a broken fuel system.

At mid-distance (4am) things were looking good for the two remaining factory 911s with Muller / van Lennep now up to fifth and Gregg / Chasseuil just three places behind in eighth.

The Sonauto Porsche’s progress was delayed between 5am and 6am after it picked up a puncture on the Mulsanne Straight which caused some damage to the front suspension and brakes. Up until this point it had been battling with one of the NART Ferrari 365 GTB/4Cs and a Kremer customer RSR for the class lead. Chassis R2 rejoined the race down in 15th position.

Thereafter, the sole Martini picked up just one position; R7 moved into fourth shortly after 9am and held station until the chequered flag. The Sonauto machine did run as high as twelfth, but had dropped back to 14th at the end. This was nevertheless good enough for third in the three-litre GT category while the Martini machine was fourth in the three-litre Group 5 class.

Victory went to the Matra MS670B of Pesarolo / Larrousse with the sister car of Jabouille / Jaussaud third. The runner up spot went to Merzario / Pace in a Ferrari 312 PB.

1973 ZELTWEG 1000KM

The penultimate World Championship event of 1973 (round nine) was the Zeltweg 1000km on June 24th.

Since Le Mans, Porsche had developed a revised rear body section with a large faired-in spoiler that extended well beyond the rear bumper and featured two vertical stabilising fins. A new flat front apron had also been created.

R6 arrived in Austria with this new arrangement (for van Lennep / Muller) while R7 (for Koinigg / Schurti) adopted the new flat-face front apron but was otherwise in the same trim seen at Le Mans two weeks prior.

Neither Muller or van Lennep had even tested the new bodywork before heading to Austria and first practice took place in extremely wet conditions. Somewhat inevitably, Muller went off while navigating the flat-out right hander at the end of the main straight; a deep patch of water sent the Porsche spinning along the barrier, denting the front and back ends of the car around wheel height.

Fortunately, the new tail was untouched and the damage was not too serious. R6 was repaired overnight and qualified tenth during the dry second session. The sister car of Koinigg / Schurti lined up twelfth.

Both cars ran like clockwork in what proved an uneventful race for Porsche. They quickly moved up to seventh (Muller / van Lennep) and eighth (Koinigg / Schurti) but both cars had dropped down a position by the chequered flag as the Scuderia Bresica Corse Alfa 33/TT/3 of Pasotti / Facetti made up for lost time.

At the sharp end, Pescarolo / Larrousse took another win for Matra.

1973 WATKINS GLEN 6 HOURS

Round ten of the ‘73 World Sportscar Championship and the season finale played out with a six hour race at Watkins Glen on July 21st.

Following the Zeltweg contest, Muller and van Lennep had stayed on for two additional days of testing at the Austrian track, during which time the long tail RSR’s two vertical stabilising fins had been connected with an adjustable central plane which much improved handling and downforce.

Both R6 and R7 arrived in the US sporting this latest bodywork; R6 would run in the blue and yellow Penske colours (for Donohue / Follmer) while R7 appeared in the white, red and blue livery of Brumos (for Gregg / Haywood).

Also in attendance was chassis R3 which Al Holbert had been campaigning in the Trans-Am series. Still in its original blue and yellow colour scheme, Holbert would share his privately owned car with John McComb.

R3 ran in the GT class while R6 and R7 contested the three-litre Prototype category.

The two Group 5 cars qualified tenth (Penske) and eleventh (Brumos) while Holbert’s machine was 19th (fourth quickest of the Group 4 machinery).

Holbert / McComb retired from proceedings at two thirds distance with suspension trouble.

By contrast, the Group 5 pairing moved up to sixth and seventh off the line and continued to run reliably throughout the race. Gregg got ahead of Donohue on lap three and the two cars proceeded to run nose to tail seemingly in a race of their own.

This latest until quarter distance when Gregg limped into the pits with a broken driveshaft which took ten minutes to fix. Meanwhile, Donohue’s Penske RSR ran like clockwork and even began to harry a couple of the purpose-built Group 5 Prototpes.

Chassis R6 ultimately came home in sixth behind the race-winning Matra of Larrousse / Pescarolo, a brace of Ferraris and the two Mirages.

After its ten minute delay, the Brumos RSR also ran reliably to claim seventh, ten laps behind its long tailed sister car.

1973 WATKINS GLEN CAN-AM

The next day (July 22nd), Watkins Glen hosted a 60 lap Can-Am race (round three of the 1973 series). Rounds one and two had been won by the Porsche 917/10s of Charlie Kemp and George Follmer as Mark Donohue’s much-fancied 917/30 had experienced trouble of one kind or another.

Chassis R7 was the only GT-style car entered for the Watkins Glen Can-Am race which comprised two 30 lap heats with the winner decided on aggregate. Against a field of super lightweight Group 7 cars, Peter Gregg managed to out-qualify a couple of two-year old privateer McLaren M8Fs to line up 19th on the 21 car grid. He went on to finish a creditable ninth overall as Mark Donohue stormed to a maiden victory in his Penske 917/30.

1973 TRANS-AM CHAMPIONSHIP

Following its retirement after a strong showing at Daytona back in February, Roger Penske had sold chassis R3 to Porsche dealer Al Holbert who ran the car in the 1973 Trans-Am Championship under the Holbert’s Porsche-Audi Inc. banner.

For 1973, the Trans-Am series comprised six races ranging in distance from just under 200 miles to just over 300 miles.

Holbert’s chief opposition came in the shape of Peter Gregg who ran a tricked out customer RSR that incorporated several parts from his Daytona winning example.

Holbert finished as runner up to Gregg at the season-opening Road Atlanta 500 and was third at Lime Rock for round two. He then teamed up with Mark Donohue for round three at Watkins Glen, but they finished a distant eighth.

The final three rounds saw Holbert pick up a fourth at Sanair, third at Road America and fourth in the season-ending Edmonton event where he shared R3 with Milt Minter. However, although R3 was classified fourth at Edmonton, the car met a spectacular end when Minter crashed on the third turn of the final lap. R3 barrel rolled and landed on its roof in what was a major accident.

Fortunately, Milt Minter was released after a few days in hospital with neck and back injuries.

The same could not be said of R3 which Al Holbert had to rebuild around the bodyshell of a 911 T for the 1974 season.

Al Holbert finished his 1973 Trans-Am campaign as runner up to Peter Gregg with 49 points compared to 56.

Text copyright: Supercar Nostalgia
Photo copyright: Supercar Nostalgia & Porsche - https://www.porsche.com

Guide: Porsche 911 2.7 & 3.0 Carrera I & J-series (1976 & 77 Model Year) - a Historical & Technical Appraisal

<<<PORSCHE PORTAL

BACKGROUND

Although the second generation 911 was launched just a few weeks before the onset of a global energy crisis, Porsche’s heavily revised model enabled the firm to weather the economic storm better than most high end manufacturers.

Prior to this, safety and emissions legislation had been rapidly tightening since the late 1960s, particularly in the USA.

When oil prices rose exponentially between 1974 and 1975, the cost of fuel suddenly became a major issue as well. The days of cheap petrol had come to an end and demand for gas guzzlers evaporated practically overnight.

Auto makers reliant on big V8 and V12 engines saw their sales figures plummet.

Because the 911’s Flat 6 engine was comparatively fuel efficient, Porsche survived relatively unscathed. The improved safety features introduced for the 1974 model year also meant the 911 could be sold into the USA without the need for the kind of ugly exterior appendages that blighted cars like the Ferrari 308.

However, building US-compliant engines was still a challenge, even for Porsche.

The flagship 911 Carrera was locked out of the American market as it couldn’t meet emissions requirements while lesser variants had to be equipped with power-sapping air pumps and (for California) thermal reactors.

At the time, Porsche had a policy of introducing major updates every two years.

For the 1974 and 1975 model years, Porsche had offered the entry level 911, the mid-range 911 S and the flagship 911 Carrera. All came with 2.7-litre engines.

In addition to these normally aspirated variants, a turbocharged 911 (the 930) was constructed from February 1975.

Production of the 1976 model year I-series 911 began in August 1975 at which point the range of normally aspirated 911s was reduced to just two: the 2.7-litre 911 Lux (marketed as the 911 S in the USA) and the 911 3.0 Carrera, which came with a new three-litre engine.

Both variants could be ordered as either a Coupe or Targa.

1976 MODEL YEAR I-SERIES UPDATES

Universal upgrades for the 1976 model year included a new body coloured driver’s side electric door mirror, improved door locks, redesigned door trim, a cast front suspension cross-member and more sound insulation. Perhaps most importantly, bodyshells were now zinc-coated to better prevent corrosion.

ENGINE / TRANSMISSION

As usual, Porsche’s air-cooled all-alloy Flat 6 motors incorporated dry-sump lubrication and a single overhead camshaft for each bank of cylinders.

Both the 2.7 and 3.0-litre engines came with a more efficient five-blade cooling fan, a larger capacity oil pump, Bosch K-Jetronic fuel-injection with automatic cold start enrichment and die-cast aluminium lower valve covers (instead of magnesium).

2.7-LITRE ENGINE

The 2.7-litre 911 Lux / 911 S engine was uprated with four journal camshafts from the 930.

Power was 165bhp at 5800rpm (10bhp down on the 1974 and 1975 model year 911 S). The torque rating was unchanged: 173lb-ft at 4000rpm.

Displacement remained 2687cc thanks to a bore and stroke of 90mm and 70.4mm respectively. Compression stayed at 8.5:1.

Engine type numbers were as follows:

911 Lux: type 911/81 (911/86 if fitted with Sportomatic) 165bhp at 5800rpm
911 S ‘49 State’: type 911/82 (911/89 if fitted with Sportomatic) 165bhp at 5800rpm
911 S ‘California’: type 911/84 (911/89 if fitted with Sportomatic) 165bhp at 5800rpm

3.0-LITRE ENGINE

The new 3.0 Carrera replaced the outgoing 2.7-litre Carrera as the most expensive normally aspirated 911 available. Like its predecessor, the three-litre Carrera was not US compliant.

The engine was essentially a normally aspirated version of the turbocharged 930 lump. Displacement of both motors was 2994cc as a result of bigger 95mm cylinder bores. Stroke was 70.4mm as per the 2.7.

Thanks to higher domed pistons, the compression ratio was increased from the 930’s 6.5:1 to 8.5:1. The two engines shared the same aluminium crankcase, Nikasil-lined cylinders and Bosch K-Jetronic fuel-injection.

Motors fitted to 911 3.0 Carreras were given type number 930/02 (or 930/12 if fitted with Sportomatic).

Peak output was 200bhp at 6000rpm (10bhp down on its predecessor). However, more importantly, the torque rating improved dramatically: an unchanged 188lb-ft was now on stream at 4200rpm instead of 5100rpm.

GEARBOX

A four speed Type 915/16 gearbox was standard throughput the range.

The five-speed Type 915/06 was an optional extra.

Another option was a clutchless manual Sportomatic transmission. As the existing four-speed Sportomatic gearbox had reached the limit of its torque capacity, a new three-speed unit was developed for these 1976 model year 911s.

CHASSIS / BODYWORK

Aside from the aforementioned zinc coating and cast front suspension cross-member (as used on the 930), the 911’s unitary steel bodyshell was unchanged.

Suspension was fully independent with torsion bars and telescopic shocks plus an anti-roll bar at either end. The front used a compact MacPherson strut arrangement with a single lower wishbone. At the rear, semi-trailing arms were installed.

Thicker torsion bars were fitted to the 3.0 Carrera as standard.

Brakes were four-wheel ventilated discs. Beefier A-type calipers were added to the 911 Lux / 911 S compared to its predecessor.

The standard wheels were 6 x 15-inch ATS ‘Cookie Cutter’ rims for the 911 Lux / 911 S while the 3.0 Carrera had 7-inch rims at the rear. In some markets, the 3.0 Carrera automatically came with Fuchs alloys.

An 80-litre fuel tank was once again located underneath the front lid but now came with lead lining to better prevent corrosion.

The 3.0 Carrera was equipped with wider rear fenders.

The impact-absorbing bumpers introduced for 1974 had proven a remarkable success. An elegant solution to tightening safety legislation, they also enabled Porsche to sell the 911 internationally with relatively few cosmetic differences from country to country.

INTERIOR

Aside from redesigned door panels with new fluted centres, no major changes were made inside.

The 911’s classic five-gauge instrument binnacle was retained. Directly behind the steering wheel was a rev counter. To the left were combined gauges for oil pressure / oil temperature and oil level / fuel. To the right was a speedometer and a clock.

Manual windows and a four-spoke steering wheel were standard.

The high-backed seats with integrated headrests introduced for the 1974 model year were retained.

OPTIONS

A comprehensive list of optional extras was available.

In addition to a five-speed manual or three-speed Sportomatic gearbox, buyers could specify Bilstein shocks, Fuchs alloy wheels, front and rear spoilers (Carrera only), a limited-slip differential, metallic paint, fog lights, headlight washers and automatic heating control.

There was also the Black Look chrome delete package and body coloured headlight surrounds, both of which were standard on the 3.0 Carrera.

Other extras included sill decals, leather upholstery, air-conditioning, tinted glass, electric windows, a heated rear window, an electric sunroof, a rear wiper and a choice of audio systems.

Wider Fuchs wheels ( 7-inch front and 8-inch rear) could also be specified on the 3.0 Carrera.

WEIGHT / PERFORMANCE

The 3.0 Carrera Coupe weighed 1120kg. It had a top speed of 149mph and 0-62mph time of 6.2 seconds.

The 2.7 S / Lux Coupe also weighed 1120kg. This version had a 135mph top speed and 0-62mph time of 7.2 seconds.

Targas weighed 50kg more and US variants all came with an additional 25kg of safety / emissions equipment.

END OF 1976 MODEL YEAR I-SERIES PRODUCTION

Production of the I-series 911 lasted until July 1976 by which time just over 9400 had been completed. This was split as follows:

911 Lux Coupe: 1868 / 911 Lux Targa: 1576
911 S Coupe: 2209 / 911 S Targa: 2179
911 Carrera 3.0 Coupe: 1093 / 911 Carrera 3.0 Targa: 479

1977 MODEL YEAR J-SERIES

The 1977 model year J-series 911s would be the last before a new SC ‘Super Carrera’ was introduced.

Production started in August 1976 and universal upgrades included Dilavar cylinder head studs, camber adjustments and further uprated K-Jetronic.

Inside, face-level vents were added in the centre of the dash, better quality carpet was fitted and more sound insulation installed. New door locks that disappeared into the door tops could be raised or lowered via a recessed circular knob on the door panel.

Targas now came with a matt black instead of stainless steel roll hoop.

Two new options were added: pinstripe fabric upholstery (only available on the 3.0 Carrera) and a Comfort Pack (available on both variants). The Comfort Pack comprised softer Bilstein shocks, electric windows and 14-inch Fuchs alloy wheels with thicker sidewall tyres. In the USA, the Comfort Pack also included cruise control.

911 S SIGNATURE

Another limited edition 911 was offered for 1977. The 911 S Signature came with Metallic Platinum paint and matching Fuchs wheels, special beige and tweed upholstery and a three spoke sports steering wheel embossed with the signature of Ferry Porsche.

END OF 1977 MODEL YEAR J-SERIES PRODUCTION

Production figures for the 1977 model year J-series 911 totalled just over 12,000 units split as follows:

911 Lux Coupe: 2449 / 911 Lux Targa: 1724
911 S Coupe: 3771 / 911 S Targa: 2747
911 Carrera 3.0 Coupe: 1473 / 911 Carrera 3.0 Targa: 646

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 2.7 Carrera RS - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<911 2.7 CARRERA RS PORTAL
<<<911 2.7 CARRERA RS FOR SALE

BACKGROUND

Having been appointed Porsche Chairman in August 1972, Dr Ernst Fuhrmann quickly decided the company’s racing programme should focus more on the 911 as opposed to purpose-built sports prototypes.

Consequently, 1973 would mark the end for the legendary 917 which had variously dominated the Group 5 and Group 7 racing classes since 1970.

With this in mind, Fuhrmann sanctioned a last hurrah for the 917 in the shape of the extreme 917/30 which pounded the Can-Am and Interserie opposition throughout 1973. Meanwhile, a new era began for the 911.

Back in 1970, the FIA had revamped the structure of its racing regulations and created a new category for modified production-based GT cars: Group 4.

Prior to 1970, the sole Grand Touring class (Group 3) had required qualifying machinery to compete in more-or-less standard trim. Group 4 on the other hand now permitted modifications like bigger engines and wider wheels which resulted in one of the most spectacular eras GT racing had ever seen.

For the 1970, ‘71 and ‘72 seasons, Porsche built a handful of highly tuned 911 ST variants for factory use and special customers. However, development of the ST had become increasingly restricted by the production 911 on which it was based. Additionally, only around half-a-dozen examples were typically built in any given year; these were not the kind of cars that could be ordered through a visit to your local Porsche dealer.

That was to change for the 1973 season when Porsche’s Carrera RS-based RSR was made available to anyone with deep enough pockets to buy one. It would take the fight to the De Tomaso Pantera GT4, Ferrari 365 GTB/4C and Chevrolet Corvette which had thus far proved the fastest Group 4 cars available.

Whereas the De Tomaso, Ferrari and Chevrolet challengers were derived from series production models that just happened to satisfy the minimum Group 4 build requirement of 500 vehicles, Porsche took a different approach. They created a hot 911 that bristled with special features and only planned to assemble the 500 cars required by the rules – a true homologation special.

The resultant 911 2.7 Carrera RS was introduced at the Paris Motor Show in October 1972. In addition to its enlarged 2.7-litre engine, the Carrera RS came with an enhanced bodyshell, uprated suspension, wider rear wheels, custom body panels and a stripped-out interior. Saving weight was of vital importance as the competition variant (the RSR) had to tip the scales at the same figure as the homologated road car.

Manufactured on the F-series 911 platform from November 1972 until July 1973, the 2.7 Carrera RS ultimately proved far more popular than anticipated. The bean counters at Porsche initially thought the company would struggle to sell the 500 cars required for homologation, however, demand for the RS proved so strong that over 1500 were eventually completed.

During a brief nine month lifespan, the 2.7 Carrera RS was Porsche’s flagship offering. Other 911s available for the 1973 model year included the 2.4-litre 911 S (190bhp), the mid-range 911 E (165bhp) and the entry-level 911 T (130bhp).

While the 911 T, E and S were all available in Coupe and Targa body styles, the Carrera RS was manufactured exclusively as a Coupe.

It was not originally compliant for sale in the US market on emissions grounds.

CHASSIS

To save weight, the Carrera RS used a unitary steel bodyshell without the usual rustproofing and sound deadening. A lightweight floorpan was fitted and the suspension mounts were reinforced.

As usual, suspension was fully independent with torsion bars and telescopic shocks. The front end used a compact MacPherson strut arrangement with a single lower wishbone. At the rear, semi-trailing arms were installed.

Specific to the Carrera RS was a light alloy front suspension support and strengthened rear suspension arms around the wheel bearings.

Unlike the 911 2.4 S (which used Koni dampers), the Carrera RS came with lighter and stiffer gas-filled Bilstein items. Thicker anti-roll bars were installed at either end.

Ventilated disc brakes were lifted direct from the 911 S. They had a 282mm diameter at the front and 290mm diameter at the rear.

The 15-inch diameter Fuchs forged alloy wheels were 6-inches wide at the front and 7-inches wide at the rear (compared to 6-inches all round on the 911 S). Spacers of 7mm were added at the back to increase track.

Initially Pirelli and later Dunlop tyres were fitted.

An 80-litre fuel tank imported from the regular 911 was located underneath the front lid.

ENGINE / TRANSMISSION

Porsche developed a special Type 911/83 engine for the Carrera RS. At 2.7-litres it was easily the biggest yet fitted to a production 911.

In typical fashion, the new engine was a dry-sumped, air-cooled, all-alloy Flat 6 with single overhead camshaft valve gear.

Nickel-silicon carbide plating was used for the cylinders which enabled bore to be taken from 84mm to 90mm. Stroke remained at 70.4mm for an overall displacement of 2687cc (a 346cc gain over the 2.4-litre motor).

The 8.5:1 compression ratio and mechanical Bosh fuel-injection were carried over from the contemporary 911 S.

Peak output was 210bhp at 6300rpm and 188lb-ft at 5100rpm.

For comparison, the engine in the 2.4-litre 911 S pumped out 190bhp at 6500rpm and 216lb-ft at 5200rpm.

Porsche fitted the Carrera RS with the five-speed Type 915 gearbox that had been introduced for the 1972 model year. Uniquely, longer ratios were added on fourth and fifth along with a heavier clutch spring.

BODYWORK

Body panels were considerably lighter than any other production 911.

Thinner steel was used for the front and rear fenders, the front lid and the roof.

The engine cover was either fibreglass or steel according to which variant was ordered (M471 Sport or M472 Touring respectively).

Both types came with a distinctive Ducktail rear spoiler.

To equalise downforce, a chin spoiler was added to the new fibreglass front apron.

All four wheelarches were subtly flared.

Carrera decals colour matched to the wheel centre inlays were normally adhered down each flank. A matching Porsche script was added across the engine lid.

INTERIOR

Inside, the 2.7 Carrera RS adopted its basic architecture from the regular 911.

Behind the familiar steering wheel with its distinctive arced spokes was a five gauge dash in the centre of which was an 8000rpm rev counter. Off to the right was a 250kmh / 150mph speedometer and either a blanking plate or clock (depending on whether the car was to Sport or Touring trim). To the left were combined read outs for oil pressure / oil temperature and oil level / fuel.

The dash itself was fashioned from soft-touch black vinyl to match the door panels and rear sidewalls.

OPTIONS

Customers could upgrade their car with an array of optional extras to include a limited-slip differential, spot lights, a rear wiper, a heated rear window, tinted glass, head rests, an electric sunroof, a radio, an electric antenna, a rear nudge bar, front lid / engine cover retaining straps and a front bumper assembly with provision for a transmission oil cooler.

Decals and wheel centres could be ordered in one of four colours: black, blue, red or green. The decals could also be deleted at no cost.

In addition, buyers had to select from one of two trim levels when placing their order: Sport (option code M471) or Touring (option code M472).

CARRERA RS SPORT (M471)

M471 Sport versions came with a fibreglass engine cover, single-piece glassfibre bumpers, thinner Glaverbel glass, minimal underseal and adhesive instead of metal badges.

Interiors were equipped with fabric Recaro single-piece bucket seats, a small diameter steering wheel, thin felt carpet, rubber floor mats, reduced sound insulation, basic door trim (without armrests, grab handles or storage bins), manual window winders, fixed rear quarter windows and a simple black headliner.

Rear seats, a clock and passenger sun visor were not fitted.

CARRERA RS TOURING (M472)

The M472 Touring version came with a Comfort pack which increased the price by nearly 10% but proved extremely popular (86% of buyers chose it).

The Touring effectively came with a 911 S cabin equipped plus the normally optional Recaro two-piece sports seats trimmed with vinyl bolsters and fabric centres. The cockpit was fully upholstered; it had rear seats, a larger diameter steering wheel, conventional door trim (with grab handles, arm rests and storage bins), electric windows, a passenger sun visor, opening rear quarter windows, a better quality headliner, thicker carpet and a full complement of sound deadening.

Touring bodyshells were also properly undersealed unlike the Sport which only had its inner wheelarches coated.

Touring variants had bumpers with chrome and rubber trim inserts from the 911 S in addition to that car’s bright metal sill covers. The single-piece fibreglass rear bumper used by the Sport made way for a multi-piece steel bumper which closely resembled the regular 911 item. Fibreglass was switched to steel when it came to the engine cover. Adhesive badges became metal.

WEIGHT / PERFORMANCE

The 975kg M471 Carrera RS Sport had a 0-62mph time of 5.4 seconds.

The 1075kg M472 Carrera RS Touring had a 0-62mph time of 5.7 seconds.

Both variants had an identical 153mph top speed.

For comparison, a standard 1973 model year 911 2.4 S Coupe weighed 1050kg, had a 0-62mph time of 6.6 seconds and a top speed of 144mph.

PRODUCTION CHANGES

In order to get the 2.7 Carrera RS certified at the lightest possible weight, the first 17 production cars were built as bare bones Carrera RS H variants (H in reference to Homologation).

These early cars tipped the scales at 960kg which was 15kg less than the M471 Sport. The 15kg weight saving was thanks primarily to a lighter passenger seat, narrower wheels, no glovebox door and more basic upholstery. Most of them also came with ‘negative’ decals with coloured lettering whereas production versions used a ‘positive’ design with transparent lettering over a coloured background.

Against expectations, the 911 Carrera RS proved so popular that the entire 500-car production run quickly sold out.

Group 4 homologation was approved on March 1st 1973.

Second and third batches of 500 cars were quickly sanctioned which meant Porsche also hit the 1000-car homologation requirement for Group 3 (approved on July 2nd 1973).

Unlike Group 4 (which permitted significant modifications to the base car), Group 3 was a category for more-or-less standard machinery with just essential safety gear added.

By April 1973, Porsche was beginning to run short of some of the lightweight parts developed for the Carrera RS. As a result, later cars often came with heavier panels, steel front support bars, standard Sekurit glass and a Silumin alloy crankcase (instead of magnesium). Most examples were fully undersealed by this point as well.

WORLD SPEED RECORD ATTEMPT

On July 28th 1973, Porsche in collaboration with Martini and Continental (who wanted to promote their new TS range of tyres) embarked upon a couple of speed record attempts with the Carrera RS at the Ehra-Lessien test track in Germany.

Driving an M471 Sport-optioned example (albeit equipped with a 2.8 RSR engine), Fritz Huschke von Hanstein (Porsche’s public relations manager) set new Class A records for 10km and 10 miles runs from a standing start attaining speeds of 153.051mph and 160.484mph respectively.

END OF PRODUCTION

2.7 Carrera RS production ran from October 1972 until July 1973.

1525 were produced in total. This figure comprised:

17 to Carrera RS H trim (all of which were left-hand drive).

200 to M471 Sport specification (of which 17 were right-hand drive).

1308 to M472 Touring specification (of which 100 were right-hand drive).

For 1974, the 2.7 Carrera RS was replaced by the even more extreme 3.0 Carrera RS which was based on the heavily revised G body platform.

COMPETITION RECORD

The RSR racer homologated by the 2.7 RS for 1973 went on to have an enormously successful season. That year it won every major series contested to include the World Sportscar Championship GT Cup, the European GT Championship, IMSA and Trans-Am.

Using the 2.7 Carrera RS, Porsche also made the decision to attack the 1973 East African Safari Rally, a gruelling 5300km event through Kenya and Tanzania that was considered the ultimate test of a machine’s toughness.

Three M471 Sport-optioned examples of the Carrera RS were prepared: two official works entries and another on a preparation and service basis for a privateer effort.

Unfortunately, none made it to the finish. The works Sobieslaw Zasada / Marien Bien entry went out with gearbox trouble shortly after having been rolled while the Bill Fritschy / Kim Mandeville machine campaigned under a Chipstead of Kensington entry dropped out shortly afterwards with its own transmission woes.

The other works car, allocated to Bjorn Waldegaard / Hans Throszelius, retired just before the finish after a broken oil pipe resulted in a cooked engine.

After a preparatory outing on the 1973 1000 Lakes Rally in Finland (where Leo Kinnunen and Atso Aho finished third in Waldegaard’s uprated Safari car), Porsche made a second attempt on the Safari Rally in 1974.

The company returned with the same three cars used in 1973, but now much-improved in every key area. On this occasion, Bjorn Waldegaard and Hans Throszelius finished the 5500km event second overall while the other two cars failed to finish (both with engine trouble).

Outside of these factory efforts, privateers went on to achieve great success with the 911 Carrera RS in Group 3 trim and the car proved enormously effective in practically all disciplines of motor sport to include circuit racing, hillclimbs and rallying throughout much of the 1970s.

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 2.7 G & H-series (1974 & 75 Model Year) - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<911 2.7 G AND H-SERIES FOR SALE

BACKGROUND

Porsche’s decision to replace the four cylinder 356 with the more expensive six cylinder 911 proved a great success; in the 911’s first nine years of production, nearly 83,000 were sold compared to 78,000 356s over a 17 year period.

Between 1964 and 1973, the first generation F-body 911 had been considerably improved. During this time, the engines used in series production variants grew from two to 2.4-litres.

For 1973, Porsche had also launched the venerable 2.7-litre Carrera RS; a limited production homologation special that spawned a successful RSR racing variant.

By the early 1970s, complying with tightening US safety and emission legislation was becoming a real headache for most high performance European manufacturers.

Fortunately, Porsche were in a financial position that enabled them to engineer a second generation 911. The resultant G-body platform would stay in production for the next 15 years and see the firm through some challenging times.

Production of the second generation 911 started in August 1973. The 1974 model year G-series derivative replaced the outgoing 1973 model year F-series.

Visually, the new 911 was given a major facelift and all three production variants now came with fuel-injected 2.7-litre engines. The entry level 911 had 150bhp, the mid-range 911 S offered 175bhp and the flagship 911 Carrera came with 210bhp.

Once again, customers were given the choice of either Coupe or Targa body styles.

In addition to the series production variants, Porsche also offered a G-series 911 Carrera RS complete with trick three-litre engine. These cars (covered separately) were built in tiny numbers to homologate an even more extreme 911 RSR racing car for the 1974 season.

CHASSIS

Although it looked quite different from the outside, the steel bodyshell used from the 1974 model year on actually changed relatively little. This was yet another testament to the original 911’s fundamentally good design.

As before, suspension was fully independent with torsion bars and telescopic shocks. The front end used a compact MacPherson strut arrangement with a single lower wishbone. At the rear, semi-trailing arms were installed.

For this latest application, the steel trailing arms were switched to lighter and stronger forged aluminium.

Thicker anti-roll bars were fitted than before: 16mm on the 911 and 911 S and 20mm / 18mm front to back on the 911 Carrera.

The top-of-the-range Carrera also came with gas-filled Bilstein shocks and bigger brake calipers. In addition, the first 200 or so featured flared rear wheelarches as per the 1973 RS.

Brakes were four-wheel ventilated discs and three different wheel styles were initially used. Standard equipment on the 911 and 911 S were 5.5 x 15-inch steel wheels with chromed hub caps. The Carrera used 16-inch Fuchs rims (6-inches wide front and 7-inches wide back).

6 x 15-inch ATS ‘Cookie Cutter’ rims were an option on the 911 and S.

A new 80-litre fuel tank shaped to accommodate the space saver wheel was installed under the front lid.

ENGINE / TRANSMISSION

Porsche’s new 2.7-litre engines were derived from that of the 1973 Carrera RS.

Compared to the 2.4-litre engines found in the outgoing line up, bore was taken out from 84mm to 90mm. Stroke remained unchanged at 70.4mm for a displacement of 2687cc.

Initially the same Nikasil-coated barrels from the Carrera RS were used, but they soon made way for Alusil components (a new aluminium silicon alloy).

These air-cooled, all-alloy Flat 6 motors ran a single overhead camshaft per bank and dry-sump lubrication.

They were available in three states of tune:

911: engine type 911/92, 150bhp at 5700rpm / 173lb-ft at 3800rpm, 8.0:1 compression ratio, Bosch K-Jetronic fuel-injection

911 S: engine type 911/93, 175bhp at 5800rpm / 173lb-ft at 4000rpm, 8.5:1 compression ratio, Bosch K-Jetronic fuel-injection

911 Carrera: engine type 911/83, 210bhp at 6300rpm / 188lb-ft at 5100rpm, 8.5:1 compression ratio, Bosch mechanical fuel-injection

The 911 and 911 S were both 10bhp up on the 911 T and 911 E that they replaced.

The engine in the 911 Carrera was identical to the unit found in the 1973 Carrera RS homologation special. It used mechanical fuel-injection instead of Bosch K-Jetronic.

A four speed Type 915/16 gearbox was standard throughput the range.

The five-speed Type 915/06 was an optional extra.

Both four and five-speed units came with longer ratios than before along with a 30% lighter clutch.

BODYWORK

Key to the second generation 911 was its new impact-absorbing bumpers.

Most manufacturers simply added ugly deformable black rubber appendages to their cars. By contrast, Porsche created a more elegant solution.

A body coloured bumper complete with black neoprene rubbing strip and matching bellows was mounted on collapsible steel tubes (or hydraulic shocks for US-bound examples).

New fenders, front lids and engine covers were required to accommodate the bumpers but the 911’s unmistakable profile remained.

Down each flank, a new body coloured side sill with integrated jacking point was mounted beneath a black rubbing strip.

The tail lights were carried over but now came with a neat red Porsche-branded reflector that linked them together.

Window frames and door handles were plated metal on the 911 and 911 S. Sometimes the side sills and headlights bezels were finished to match.

By contrast, the flagship 911 Carrera came with Porsche’s ‘Black Look’ which was an option on other variants. The ‘Black Look’ came with anodised black metal for the window frames, door handles and the rollover hoop on Targas.

Targas came with a removable roof panel that could be stowed under the front lid.

INTERIOR

Although the cockpit of this latest variant retained the same basic layout as before, there were myriad quality improvements.

New high-backed seats came with integrated headrests and inertia-reel seat belts. The brake pedal was lengthened for a lighter action and velour carpet was fitted throughout the range.

The 911’s familiar five gauge instrument layout was retained but the dash now came with soft-touch knobs, side window demisting vents, an electric tachometer and quartz clock.

Redesigned door panels featured an armrest that doubled up as a storage bin.

Manual windows and a four-spoke steering wheel were standard on the 911 and 911 S.

The 911 Carrera came with electric windows and a small diameter three-spoke steering wheel. It also featured opening rear quarter windows which were optional on the other models.

OPTIONS

Porsche offered a comprehensive list of extras to include: Koni dampers, bigger anti-roll bars, an oil cooler, a five-speed gearbox, metallic paint, fog lights, headlight washers, Black Look chrome delete, Porsche or Carrera wheelbase decals and the RS-style ‘Ducktail’ rear spoiler (outlawed in Germany on safety grounds).

Comfort options included full leather upholstery, Recaro sports seats, air-conditioning, tinted glass, a radio, electric antenna, heated rear window, rear wiper, electric windows, electric sunroof and electric mirrors.

Another optional extra available on the entry level 911 and 911 S was four-speed Sportomatic transmission which offered clutchless manual gear changing. When specified, engine type numbers became 911/97 for the 911 and 911/98 for the 911 S.

Sportomatic was not available on the flagship 911 Carrera.

USA VERSION / 911 2.7 CARRERA

The 911 Carrera was banned from the USA in its normal 210bhp configuration as the mechanical fuel-injection and radical valve timing did not meet Federal standards.

Instead, Porsche fitted US-bound Carreras with the 175bhp engine from the 911 S.

Changes made to American-spec. 911s over their rest of the world counterparts included extra sidelights, red tail lights and bumpers mounted on hydraulic shocks.

WEIGHT / PERFORMANCE

Thanks to some clever engineering, the weight of these second generation 911s was initially only 25kg up on the outgoing 2.4-litre variants.

In standard trim, they typically weighed in at around 1075kg (Coupe) and 1125kg (Targa).

Performance figures were as follows:

911: 131mph top speed, 0-62mph in 7.6 seconds
911 S: 139mph top speed, 0-62mph in 6.6 seconds
911 Carrera: 149mph top speed, 0-62mph in 6.1 seconds

OIL CRISIS

Production started in August 1973 but within a few months, the world was in the midst of an energy crisis.

Arab OPEC members announced an embargo on oil sales to the USA, UK, Canada, Japan and the Netherlands in response to the USA's support for Israel in the Yom Kippur War. Egypt and Syria, with the support of other Arab nations, had begun a military campaign to regain Arab territories lost during the 1967 Six Day War (when Egypt, Syria and Jordan had been the aggressors).

Oil prices rose exponentially and remained at elevated levels for the next two years.

Demand for gas guzzlers evaporated practically overnight. However, Porsche weathered the storm in remarkable fashion and sales figures were only slightly down on the previous year.

By contrast, some lower volume manufacturers went bankrupt and others struggled to survive.

END OF 1974 MODEL YEAR G-SERIES PRODUCTION

Just under 11,500 G-series 911s were constructed for the 1974 model year with production split as follows:

911 Coupe: 4014 / 911 Targa: 3110
911 S Coupe: 1359 / 911 S Targa: 898
911 Carrera Coupe: 1564 / 911 Targa: 433

1975 MODEL YEAR H-SERIES

In August 1974, Porsche began production of the 1975 model year H-series 911.

Universal upgrades included extra sound insulation and an additional heater fan.

Steel wheels were deleted from the range and 911 Carreras now came with body coloured headlight surrounds as standard.

The Ducktail rear spoiler option was dropped in favour of a new 3.0 Carrera RS-style Whale Tail. When this was specified, a discrete matt black chin spoiler was added at the front of the car.

The spoiler option pack was made standard on US-bound 911 Carreras which still came with the 175bhp 911 S engine rather than the rest of world 210bhp unit.

Although specifications remained the same, 911 and 911 S engines were given the following new type numbers for 1975.

911: from type 911/92 to 911/41 (from 911/97 to 911/46 if fitted with Sportomatic)

911 S: from type 911/93 to 911/42 (from 911/98 to 911/47 if fitted with Sportomatic)

Porsche dropped the entry level 911 from the US market and now offered American customers two types of de-tuned 911 S engine (which were also fitted to US-bound 911 Carreras):

911 S ‘49 State’: type 911/43 (911/48 if fitted with Sportomatic) 165bhp at 5800rpm, air pump fitted

911 S ‘California’: type 911/44 (911/49 if fitted with Sportomatic) 160bhp at 5800rpm, air pump fitted plus thermal reactors and exhaust gas re-circulation equipment.

911 / 911 S 25TH ANNIVERSARY

Porsche offered the 911 and 911 S in a special 25th Anniversary edition during the 1975 model year.

These very high specification cars came with Diamond Silver Metallic paint, Black-Look chrome delete, Fuchs wheels, a five-speed gearbox, special silver and black tweed trim, a three-spoke steering wheel from the Carrera, a numbered plaque on the passenger side of the dash, a thicker rear anti-roll bar, heated rear window, headlamp washers and a Blaupunkt Bamberg radio with electric antenna.

1063 were built.

END OF 1975 MODEL YEAR H-SERIES PRODUCTION

Production of the H-series 1975 model year 911 ended in July 1975.

From February of 1975, Porsche had also begun to build the 911 Turbo (930).

Normally aspirated production was down slightly on the previous year with just under 8000 units completed split as follows:

911 Coupe: 1238 / 911 Targa: 998
911 S Coupe: 2695 / 911 S Targa: 1783
911 Carrera Coupe: 518 / 911 Carrera Targa: 197 / 911 Carrera USA: 395

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 3.3 Turbo (930) - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<911 3.3 TURBO (930) FOR SALE

BACKGROUND

The turbocharged 930 produced from early 1975 was Porsche’s flagship 911 and arguably the most capable supercar of its time.

Performance-wise, the 930 was on a par with anything Ferrari and Lamborghini had to offer. Unlike its Italian rivals though, the turbocharged 911 was practical enough for everyday use and offered bulletproof reliability.

However, the 930 was not without a dark side. Infamous lift-off oversteer led to it being dubbed the Widowmaker, but tales of high-speed death and destruction did little to diminish the car’s ongoing popularity. Indeed, sales massively exceeded expectations.

Porsche had conceptualised the 930 as a limited run of 400 cars that would be built to secure homologation into the Group 4 and 5 racing categories. As had been the case with the firm’s previous homologation special (the 911 2.7 Carrera RS of 1972-1973), demand far exceeded the number required by the FIA.

Unlike the 2.7 Carrera RS, the 930 became a permanent fixture in the Porsche line up.

Upon its 1975 launch, the turbocharged 911 became Porsche’s alternative to the Ferrari 365 GT4 BB and Lamborghini Countach. By late 1977, Ferrari had switched to the torquier 512 BB and, while Lamborghini were on the brink of administration, the wild new Countach S was unveiled in early 1978.

To keep up with the competition, Porsche offered a further uprated 930 from September 1977 (for the 1978 model year).

ENGINE / TRANSMISSION

At the heart of the revised model was its new Type 930/60 motor - another air-cooled all-alloy Flat 6 with two valves per cylinder, single overhead camshafts and dry-sump lubrication.

For this latest application, displacement was increased from 2994cc to 3299cc. Each cylinder had been bored to 97mm (up from 95mm) while stroke was extended from 70.4mm to 74.4mm.

Compression was also increased (from 6.5 to 7.0:1) and a larger but lighter KKK K27 turbo replaced the old 3 LDZ type.

One of the most important upgrades was the addition of an air-to-air instead of water-to-air intercooler. This dramatically reduced charge air temperature.

Other upgrades included enlarged main bearings and beefier big ends.

Fuel-injection and ignition was via the latest Bosch K-Jetronic.

Output figures for the 3.3-litre engine were a considerable improvement. Power went from 260bhp to 300bhp at an unchanged 5500rpm. The torque rating jumped from 253lb-ft to 303lb-ft at an unchanged 4000rpm.

One universal upgrade made across the 911 range for the 1978 model year was a bulky new Porsche-designed rubber-centre clutch that resulted in engines being mounted 30mm further back in the chassis.

The aluminium-cased four-speed gearbox was given new ratios and re-designated Type 930/34.

CHASSIS

Porsche’s steel unibody chassis was unchanged as was the existing fully independent suspension layout.

At the front, Porsche employed a MacPherson strut arrangement with lower wishbones, longitudinal torsion bars and anti-dive geometry. The back end used semi-trailing arms with anti-squat.

Bilstein shocks were fitted all round along with anti-roll bars at either end.

Arguably the biggest criticism aimed at the three-litre 930 was its stopping power. The original Turbo had an arrangement lifted direct from the 2.7-litre Carrera, but this latest 930 was enhanced with 917-derived cross-drilled and ventilated discs with aluminium hubs and finned four piston alloy calipers.

Disc diameter went from 282.5mm to 304mm at the front and 290mm to 309mm at the rear. Disc thickness was also increased.

Right-hand drive 911 Turbos were finally fitted with the Hydrovac brake servo that had been present on left-hand drive examples since late 1976.

Forged light alloy wheels were supplied by Fuchs. They measured 16 x 7-inches at the front and 16 x 8 at the rear. Dunlop or Pirelli tyres were usually issued.

BODYWORK

The only cosmetic change made to these 3.3-litre Turbos was a new rear spoiler which was positioned on a boxier housing to accommodate the bulky air-to-air intercooler.

The main body of the spoiler was also reconfigured. It now featured a flattened top with myriad cooling vents and a thicker rubber surround than before.

That no other visual updates were deemed necessary at a time of rapid design evolution was a testament to the 911’s classic good looks.

INTERIOR

The same was true inside. By this time, the half leather seats with tartan fabric centres and matching door panels were seen less and less as full leather upholstery generally took over.

The familiar five gauge instrument binnacle featured a central tachometer with integrated boost indicator flanked to the right by a speedometer and clock. To the left was a combined oil pressure / oil temperature gauge and a read out for oil level / fuel.

Standard equipment included electric windows, a four-speaker stereo with front wing-mounted electric antenna, a rear wiper, headlight washers and front fog lights.

OPTIONS

Customers could optionally specify a ZF limited-slip differential, rear fog lights, air-conditioning, an electric sunroof and a central console.

At this stage, the 930 was only available as a Coupe.

WEIGHT / PERFORMANCE

Compared to the outgoing variant, the 3.3-litre Turbo was 7mph faster (161mph) and 0.6 of a second quicker from 0-62mph (5.1 seconds).

Weight went from 1195kg to 1300kg.

USA VERSION

As usual, tighter safety and emissions legislation in the USA meant those cars sent across the Atlantic came with several modifications.

All 930 motors were fitted with an air pump to reduce exhaust emissions regardless of destination. However, the ‘49 US-state’ Type 930/61 engine additionally came with thermal reactors while California-bound Turbos used Type 930/63 units further burdened by a vacuum control.

Output of both versions was 265bhp at an unchanged 5500rpm. The torque rating was also slightly lower: 291lb-ft instead of 303lb-ft at an unchanged 4000rpm.

Cosmetic changes to these US-spec. derivatives included amber running lights, red rear indicators and thicker body coloured headlight shrouds. Weight was unaffected but performance figures were slightly inferior.

1978 MODEL YEAR I-SERIES PRODUCTION

Production of the 3.3-litre 930 began in September 1977.

In total, 1757 were built on the 1978 model year I-series platform.

1979 MODEL YEAR J-SERIES

The 1979 model year L-series followed in September 1978.

All cars now came with the extended centre console as standard.

Chequered Pascha upholstery was added to the options list.

US-bound 930s were uprated with air-conditioning at no cost.

In total, 2552 examples were completed.

1980 MODEL YEAR A-SERIES

Instead of 1980 model year 911s adopting the expected K-series moniker, Porsche started from scratch to reflect a new 17 instead of 10-digit chassis numbering system.

These latest A-series 930s came with dual instead of single exhausts and a brass tube oil cooler.

Significantly, the cost of compliance meat Porsche stopped supplying the 930 in the USA and Japan. This had a dramatic affect on sales and just 840 A-series 911 Turbos were manufactured which was less than a third of the previous year’s total.

1981 MODEL YEAR B-SERIES

Production then dropped to 761 units for the 1981 model year B-series derivative which came with seamless steel tubes instead of braided fuel lines and improved diaphragm clutch springs.

A new sports seat with bigger bolsters was added to the options list.

1982 MODEL YEAR C-SERIES

The only significant change made for the 1982 model year C-series 930 was the addition of a new high powered alternator with integrated voltage regulation.

Production rose for the first time in two years and 1027 were built.

1983 MODEL YEAR D-SERIES

For the 1983 model year D-series 930, a series of key developments were introduced.

Porsche’s revised Type 930/66 engine was no larger or more powerful than before but did offer some useful extra torque (up to 318lb-ft from 303lb-ft at an unchanged 4000rpm).

With the aim of reducing emissions, a new exhaust system now featured the wastegate exhaust flowing direct to the atmosphere. The Bosch K-Jetronic came with a new warm-up regulator.

1080 of these D-series derivatives were built, another slight increase on the year before.

1984 MODEL YEAR E-SERIES

Further developments were introduced for the 1984 model year E-series 930.

Changes included a brake wear indicator on the dash, a three-speed heater, a new type of upholstery with Porsche script and revised pressure-fed timing chain tensioners.

Only 881 were assembled, the lowest figure for any full year of production.

1985 MODEL YEAR F-SERIES

Industrial action resulted in the 1985 model year F-series 930 not entering production until October 1984 (instead of September).

The F-series came with thicker anti-roll bars, an enlarged 85-litre fuel tank and bigger brake master cylinder.

Inside, re-designed high-backed seats were heated and electrically operated. Central locking became standard and the radio antenna was integrated to the windscreen.

A short shift gear lever was added along with a new four-spoke steering wheel.

The door handles and storage bin lid were now upholstered with leather.

Sports seats became a no-cost option.

1148 of these 1985 model year 911 Turbos were manufactured, a 34% rise on the previous year.

1986 MODEL YEAR G-SERIES

Production of the 1986 model year G-series 930 got underway in September 1985.

It featured new Bosch LE-Jetronic fuel-injection, 9-inch wide rear wheels (up from 8-inches), a subtly reworked dash fascia, sun visors with covered vanity mirrors and front seats mounted a little lower than before.

Thanks to the arrival of a new emissions friendly Type 930/68 engine, the 911 Turbo was re-introduced to the US market after a five year absence.

Equipped with a three-way catalytic converter, Lambda oxygen sensors and DME engine management, the US-spec. Type 930/68 motor produced 282bhp at 5500rpm and 288lb-ft at 4000rpm.

With the 930 now available in the US again, production surged to 2670 units, over half of which were sent across the Atlantic.

1987 MODEL YEAR H-SERIES

For the 1987 model year, Porsche began to offer the 930 in Targa and Cabriolet body styles as well as the original Coupe format.

At the same time, an 'Exclusive' options programme was officially introduced that enabled customers to specify all kinds of high end modifications.

This most famously included option M505: the Turbo S Flachbau (covered separately).

In addition to Flat Nose bodywork, the M505 package included side skirts, vented rear wheelarches, a deep front spoiler with supplementary oil cooler, a 330bhp engine, four-outlet exhaust and various interior upgrades. These features could also be specified with normal 911 headlights and cars equipped as such are sometimes referred to as Turbo S variants.

Other updates introduced for the 1987 model year included a modified tail reflector strip that incorporated the fog and reverse lights which had previously been located underneath the back bumper.

Inside, fully electric seats were made standard.

The brakes were improved with bevelled vents to assist cooling.

After record sales the previous year, 1987 was even better. 3094 Turbos were sold in various configurations.

1988 MODEL YEAR I-SERIES

This figure dipped to 2784 during the 1988 model year when little was changed in the transition from H to I-series. A passenger door mirror and eight-speaker stereo were made standard but more significant changes were on the way.

1989 MODEL YEAR J-SERIES

For the 930’s final year in production (1989), Porsche switched from the four-speed Type 915 gearbox to the five-speed G50 unit.

An alarm was added along with a smaller rear anti-roll bar (this having been offset by more prominent torsion bars and stiffer shocks).

These 1989 model year J-series 930s were undoubtedly the best of the bunch. 2524 were sold in various configurations.

END OF PRODUCTION

The 1989 figure took total 911 Turbo sales between 1975 and 1989 to just under 20,000 units.

A replacement (the 965) was launched at the Geneva Motor Show in March 1990. It entered production that September for the 1991 model year.

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 2.4 E & F-series - a Historical & Technical Appraisal

<<<PORSCHE PORTAL

BACKGROUND

When Porsche introduced the 2.2-litre 911 in September 1969, many felt the model had reached the limit of its potential.

Rumours swirled that an entirely new replacement was on the cards; a big front engined Gran Turismo with a conventional water-cooled engine that would take the firm further upmarket.

Porsche were actively considering such a machine and gave it the green light in 1971, but the resultant 928 never matched the commercial appeal of the iconic 911.

Thankfully, development continued on the 911 and, in September 1971, Porsche unveiled their latest iteration: the 2.4-litre E-series.

These 2.4-litre derivatives were manufactured for the 1972 and 1973 model years. With their powerful, torquey engines and new Type 915 gearboxes, they widely came to be regarded as the best F-body 911s prior to the advent of the heavier impact bumper G-body introduced for the 1974 model year.

2.4-litre 911s were offered in three states of tune and two alternative body styles (Coupe and Targa). There was the entry level 911 T, the mid-range 911 E and the flagship 911 S. Each variant came with progressively more power than the last.

CHASSIS

For this latest application, the 911’s unitary steel bodyshell was little unchanged.

Suspension was fully independent with torsion bars and telescopic shocks. The front end used a compact MacPherson strut arrangement with a single lower wishbone while at the rear, semi-trailing arms were installed.

The wheelbase was extended by 3mm thanks to altered rear suspension mounting points (an attempt to eliminate compound movement of the strut). The change had the happy side effect of facilitating extra suspension travel which further improved ride quality.

The rear semi-trailing arms were revised to allow their removal without having to drop the engine out of the car.

Boge’s hydro-pneumatic shocks previously used on the 911 E were made optional as this variant reverted to the same suspension set up as the 911 T. The 911 S still came with Koni dampers.

The 15-inch Fuchs alloys that were standard on all 2.2-litre 911s were now optional on the 911 T and 911 E. Standard equipment for the 911 T was pressed steel 5.5-inch rims while the 911 E came with new 6-inch wide ATS cookie cutter alloys. 6-inch Fuchs forged alloys were fitted to the 911 S and, in some markets, they were an automatic upgrade for other variants as well.

Front and rear anti-roll bars were fitted as standard to the 911 S which now came with a secondary oil cooler fitted in the right-hand front fender.

ENGINE / TRANSMISSION

The bigger 2.4-litre engines not only gave more power and torque, they also helped Porsche comply with increasingly stringent emissions legislation. Furthermore, the 2.4 lump enabled the use of lower compression ratios as fuel quality was dropping in lots of markets.

Thanks to a 4.4mm lengthening of the stroke (from 66mm to 70.4mm), displacement rose from 2195cc to 2341cc. Bore dimensions were unchanged at 84mm.

These engines featured new camshafts, shorter and lighter con rods, reduced height piston crowns cooled by individual oil jet sprays, improved porting, larger big ends, full crankshaft counter-balancing, a crankcase stiffened around the main bearings and a new forged crankshaft.

Specifications for the three variants were as follows:

911 T: Type 911/57, 130bhp at 5600rpm / 196lb-ft at 4000rpm, 7.5:1 compression, two Zenith 40 TIN carburettors.

911 E: Type 911/52, 165bhp at 6200rpm / 206lb-ft at 4500rpm, 8.0:1 compression, Bosch mechanical fuel-injection.

911 S: Type 911/53, 190bhp at 6500rpm / 216lb-ft at 5200rpm, 8.5:1 compression, Bosch mechanical fuel-injection.

While the 911 E and 911 S did not require any compliance modifications, 911 Ts destined for the USA, Australia, Japan and Canada used Bosch mechanical fuel-injection instead of Zenith carburettors. These Type 911/51 engines produced 140bhp at 5600rpm and 200lb-ft at 4000rpm (10bhp and 4lb-ft more than the rest of the world offering).

All 2.4-litre 911s came with a new Type 915 gearbox that afforded greater torque capacity than the outgoing 901 unit albeit at the expense of an additional 9kg.

The 915 gearbox had a conventional gate pattern instead of the old dogleg first.

It was offered with both four-speeds (911 T) and five-speeds (911 E and 911 S).

The four-speed semi-automatic Sportomatic option was still available and given a new type number (925). Engines equipped as such came with the following type numbers: 911/67 (911 T), 911/62 (911 E) and 911/63 (911 S). The fuel-injected 911 T with Sportomatic was engine type 911/61.

BODYWORK

Cosmetically, E-series 911s came with a distinctive oil filler cap positioned behind the right-hand door which was opened by a button on the adjacent door pillar.

Other universal changes included a black instead of aluminium engine grille and gunmetal model script rather than anodised gold.

A bigger driver’s side wing mirror was also fitted (a passenger mirror was still an optional extra).

The 911 S now came with a new front spoiler said to reduce front-end lift by 40%. This handsome appendage was optional on the 911 E and 911 T.

INTERIOR

Only minor alteration were made inside.

The old basket-weave dash insert was dropped in favour of plain vinyl that matched the rest of the upholstery.

Also gone was the 911 logo previously mounted on the passenger side of the dash.

Wrinkled black seat hinges replaced chrome.

The 911 S came with door sill kick plates (optional on other variants).

All US-spec. cars came fitted with inertia reel seat belts.

Aside from sharing its leather steering wheel with the 911 S, the 911 E interior was now based on the 911 T.

OPTIONS

Customers could enhance their cars by choosing from the huge numbers of optional extras available. These included sports seats, air-conditioning, full or half leather upholstery, a limited-slip differential, electric windows, fog lights, spot lights, an electric sunroof, Fuchs wheels and head rests.

A new 85-litre fuel tank with space saver tyre was offered for the first time while the 911 S could still be specified with an enormous 110-litre fuel cell.

Various radio options were offered along with a Comfort pack for the interior and an ‘S’ kit that added the front spoiler, wheels and sill plates from the 911 S to the 911 E or T.

WEIGHT / PERFORMANCE

Standard Coupes weighed 1050kg and Targas were 1100kg.

Performance figures were:

911 T: 126mph top speed and 0-62mph in 8.8 seconds.
911 E: 138mph top speed and 0-62mph in 7.8 seconds.
911 S: 144mph top speed and 0-62mph in 6.6 seconds.

END OF 1972 MODEL YEAR E-SERIES PRODUCTION

Production began in August 1971 and continued for twelve months during which time just under 13,000 were built. This figure was split as follows:

911 T Coupe: 4894 / 911 T Targa: 3344
911 E Coupe: 1124 / 911 E Targa: 861
911 S Coupe: 1750 / 911 S Targa: 989

1973 MODEL YEAR F-SERIES

Porsche’s 1973 model F-series 911s were produced from August 1972 and ushered in another round of upgrades.

The oil filler located behind the right-hand door was dropped after owners and petrol station attendants repeatedly mistook it for the fuel filler.

The horn grilles and supplementary light surrounds at either end were now finished in black instead of chrome.

A rear wiper was fitted across the range.

Airflow to the oil cooler was improved by modifying the baffles.

For the first time, Targas, were available in right-hand drive.

US-bound machinery came with black rubber overrider pads as dictated by ever-tightening American safety legislation.

In January 1973, the fuel-injected US-spec. 911 T switched to a Bosch K-Jetronic Continuous Injection System and new camshafts were fitted with reduced valve opening timing.

END OF 1973 MODEL YEAR F-SERIES PRODUCTION

Production of the F-series 911 continued until July 1973 and just over 13,000 were built in the following configurations:

911 T Coupe: 5071 / 911 T Targa: 3594
911 E Coupe: 1366 / 911 E Targa: 1055
911 S Coupe: 1430 / 911 S Targa: 925

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 2.2 C & D-series - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<911 2.2 C & D-SERIES FOR SALE

BACKGROUND

Porsche’s first 21 years as an auto manufacturer had seen the firm grow at an exponential rate.

From the trickle of hand-built Volkswagen-based 356s that emerged out of a cramped converted sawmill in the backwaters of Austria, the company had returned to Germany where workshop space was leased until there was enough money for a brand new factory.

The expectation had been that maybe a few hundred 356s would satisfy demand. By the time production stopped in 1965, nearly 80,000 had been delivered.

The move further upmarket with the larger six cylinder 911 was a gamble but ultimately paid off; it was not just a critically acclaimed commercial success, but quickly came to be regarded as an icon of 20th century automotive design.

After four years in production, Porsche released a 911 with a larger 2.2-litre engine. The original two-litre unit had served the firm well, but the move to a bigger displacement for the 1970 model year meant more power, improved torque and, most importantly, better performance.

For most of the 1960s, Porsche had the mid-range GT market pretty much sewn up. However, the 911’s enormous commercial success did not go unnoticed over at Ferrari, Lamborghini and Maserati. All three Italian firms had entry level 2+2 models in the pipeline and were determined to attract customers that would otherwise have purchased a 911.

With competition hotting up, the C-series 911 entered production in August 1969.

These 2.2-litre 911s were manufactured for the 1970 and 1971 model years during which time, Porsche joined the big league by taking back-to-back wins at the Le Mans 24 Hours with their Flat 12-engined 917s.

Although it had been Ford that first broke Ferrari’s dominance at Le Mans, sports car racing throughout the 1970s and 1980s would be dominated by Porsche.

This latest 911 was once again available as either a Coupe or Targa and customers could choose from engines in three alternative states of tune: there was the entry level 125bhp 911 T, the more luxurious 155bhp 911 E or the flagship 180bhp 911 S.

ENGINE / TRANSMISSION

The familiar all-alloy air-cooled Flat 6 with its single overhead camshafts and dry-sump lubrication was bored from 80mm to 84mm. Stroke stayed at 66mm for a displacement of 2195cc (a gain of 204cc over the outgoing unit).

Porsche’s engineers fitted bigger valves, new head gaskets and more cooling fins on the cylinder barrels which had modified ends to clear the longer bolts required by stronger con rods.

Engine type numbers were given a 911 instead of 901 prefix and specifications were as follows:

911 T: Type 911/03, 125bhp at 5800rpm / 177lb-ft at 4200rpm, 8.6:1 compression, two Zenith 40 TIN carburettors.

911 E: Type 911/01, 155bhp at 6200rpm / 191lb-ft at 4500rpm, 9.1:1 compression, Bosch mechanical fuel-injection.

911 S: Type 911/02, 180bhp at 6500rpm / 199lb-ft at 5200rpm, 9.8:1 compression, Bosch mechanical fuel-injection.

Cheaper Zenith carburettors replaced the Webers on the new 911 T which also now came with the CD ignition fitted to the rest of the range. Compression was unchanged. Output rose by 15bhp and 21lb-ft at the same engine speeds as before.

The 911 T was the only 2.2-litre derivative that had a specific US-market version as the 911 E and 911 S could be exported to the States without needing any compliance modifications. Output was unaffected but the emissions-equipped 911 T engine was given a new type number (911/07).

The new 911 E came with softer cams to make it more appealing to the general public. Compression was once again unchanged. Output was 15bhp higher and this was developed at 300rpm less than before. The torque rating was up by 16lb-ft at an identical engine speed to its predecessor.

The new 911 S had its compression ratio reduced from 9.9 to 9.8:1. It developed 10bhp more than its predecessor at 300rpm less. Peak torque was up by 16lb-ft at 300rpm less than before.

Whereas the 911 E and 911 S came with a five-speed gearbox, the 911 T had only four-speeds.

All variants came with a thicker diameter clutch and redesigned diaphragm to make pedal operation easier.

Like the engines, gearbox type numbers were changed from 901 to 911.

Porsche’s four-speed Sportomatic semi-automatic gearbox was available on the 911 T and 911 E but not the 911 S. Cars equipped as such had different engine type numbers: 911/06 for the 911 T (911/08 if US-bound) and 911/04 for the 911 E.

CHASSIS

The unitary steel bodyshell shared by all varieties of 911 was now coated with a Tectyl oil-based anti-corrosion fluid.

Suspension was fully independent with torsion bars and telescopic shocks fitted all round. The front end used a compact MacPherson strut arrangement with a single lower wishbone while at the rear, semi-trailing arms were installed.

For these 1970 model year C-series derivatives, the front suspension mounting points were moved 14mm forward to reduce front wheel castor and lighten the steering at low speeds.

Front torsion bar adjustment was made easier on the 911 T and 911 S.

The E kept its hydro-pneumatic struts.

Ventilated disc brakes were now fitted across the board but, to keep costs down, iron rather than alloy calipers were used on the 911 T.

Also standard were 6 x 15-inch Fuchs forged alloy wheels although 911 Ts destined for certain markets did still come with steel rims.

A bigger 62-litre fuel tank was installed underneath the front lid. This was vented on US-bound 911s so fuel vapour could escape.

BODYWORK

Cosmetically, no major changes were made.

Upgrades included new door handles with an opening trigger behind the catch and improved Bosch H1 headlights. A 2.2 decal was applied to the base of the rear screen.

To save weight, aluminium was used instead of steel for the engine cover and the central part of the front bumper on 911 E and 911 S variants. The E and S also had anodised gold badging at the back compared to bare aluminium for the 911 T.

C-series 911 Targas benefited from improved roof seals.

INTERIOR

Relatively little was changed inside.

The door panels now came with a large storage bin underneath the arm rest and recessed pull-type door release catches were fitted instead of an exposed button.

The steering column mounted stalks were revised and an intermittent function was added to the windscreen wipers.

Ignition keys now came with a plastic handle to replace the all-metal keys of early cars.

Otherwise, the 911s basic cockpit architecture was retained.

Vinyl upholstery was standard but full or half leather with fabric inserts could also be specified.

OPTIONS

New options introduced for the C-series 911 included electric windows and a ZF limited-slip differential.

Other desirable options included front head rests, a rear wiper, an electric sunroof, tinted glass, spot lamps, fog lights, Koni shock absorbers and a choice of radios.

Uniquely, the 911 S could be ordered with a long-range 110-litre fuel tank that left little space for anything else underneath the front lid.

END OF 1970 MODEL YEAR C-SERIES PRODUCTION

C-series production started in August 1969 and continued until July 1970. Build totals during that time were as follows:

911 T Coupe: 6544 / 911 T Targa: 2545
911 E Coupe: 1971 / 911 E Targa: 933
911 S Coupe: 1744 / 911 S Targa: 729

1971 MODEL YEAR D-SERIES

The subsequent 1971 model year D-series 911 came with another series of updates.

In the fight against corrosion, bodyshells were now galvanised with a zinc coating applied to exposed underbody areas.

Crankcase squirters were introduced to improve piston cooling. There was also a new type of sealed chain tensioner while minor detail alterations were made to the fuel-injection system.

Inside, a new twist and pull type knob was fitted to the glovebox and a ‘1969 & 1970 World Championship of Makes’ decal was applied to the driver’s side rear window.

US-spec. derivatives now came with a fuel evaporative control system to prevent the release of vapour into the atmosphere.

A heated front windscreen was added to the options list.

END OF 1971 MODEL YEAR D-SERIES PRODUCTION

D-series production ended in August 1971 to make way for the new 2.4-litre E-series variant.

Build totals were as follows:

911 T Coupe: 2517 / 911 T Targa: 3476
911 E Coupe: 1088 / 911 E Targa: 935
911 S Coupe: 1430 / 911 S Targa: 788

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: Porsche 911 2.2 Carrera RSR Turbo - a Historical & Technical Appraisal

<<<PORSCHE PORTAL
<<<911 2.2 CARRERA RSR TURBO PORTAL

BACKGROUND

In early February 1974, Porsche announced they had discontinued their Group 7 racing programme with the 917. Cost had a part to play, but the new company Chairman, Ernst Fuhrmann, also held a desire to focus on racing cars that bore a greater resemblance to production models.

With some of the most powerful turbocharged engines ever seen, Group 7 Porsche 917s had toppled the formidable McLaren team to win the Can-Am Championship in 1972 and 1973. On European soil, they also secured the Interserie titles of 1972 and 1973.

These 917s were almost always run by Porsche satellite teams such as those of Roger Penske, Vasek Polak, Brumos and Willi Kauhsen. However, the works team did not sit idly by. Under the Martini Racing banner, Porsche successfully campaigned an experimental batch of 911 Carrera RSRs in the 1973 World Sportscar Championship.

With attention no longer being diverted elsewhere, for 1974, the works 911 programme was stepped up a gear.

The result was the first turbocharged 911: the Carrera RSR Turbo.

It would pave the way for a production 911 Turbo (the 930) which would in turn be used to homologate a racing variant (the 935) for the FIA’s hotly anticipated Group 5 Silhouette regulations set to be introduced for 1975. A less highly tuned Group 4 iteration (the 934) would also be built.

The RSR Turbo was a rolling laboratory for turbo technology and looked about as far removed from the road-going 911 as one could imagine.

Built for the existing Group 5 Prototype class, it was not constrained by production-based regulations and was thus able to run with super wide wheels and enormous spoilers.

However, as a Group 5 entry, it would be up against conventional Prototypes from Matra (MS670), Alfa Romeo (33/TT/12) and Mirage (GR7) which meant class wins were unlikely.

Meanwhile, the Group 4 category was left to Porsche’s customer teams in 1974. For this, Porsche supplied the 911 3.0 Carrera RSR to anyone with sufficient funds.

Unlike the customer 1974 RSR, the works RSR Turbo was modified almost completely out of recognition. Little other than the floor pan, roof and basic mechanical bits such as crankcase and gearbox remained in what was a foretaste of the incoming Silhouette formula where radically modified machines retained not much more than the original engine block, engine position and silhouette of the base model.

CHASSIS

The RSR Turbo’s galvanised steel bodyshell most notably featured a new bolted aluminium rear spaceframe to support the engine, transmission and rear suspension.

New coil sprung suspension replaced the standard torsion bar arrangement and allowed Porsche to remove the heavy duty crossmember that normally anchored the suspension and supported the engine.

The suspension was specially fabricated with improved geometry. Titanium coil springs and Bilstein gas-filled dampers were fitted all round along with adjustable anti-roll bars at either end. The lower front wishbones had anti-dive built into the pick-up points.

Cross-drilled and ventilated discs with four piston calipers and titanium hubs were lifted from the 917. Brake balance was cockpit-adjustable for both axles.

The magnesium centre-lock wheels had a 10.5-inch diameter and were shod with Dunlop Racing tyres. They measured 15-inches wide at the front and an extraordinary 17-inches wide at the rear.

ENGINE / TRANSMISSION

As Group 5 had a three-litre engine limit and turbo boost multiplier of 1.4, Porsche needed an engine with a maximum displacement of 2150cc. They settled on 2143cc thanks to a special motor that was de-bored to 83mm and de-stroked to 66mm.

This Type 911/76 engine used the most exotic components available to ensure it was light, powerful and reliable.

Nikasil-lined cylinders and heads were fitted along with four instead of three bearing camshafts. There were also new pistons, titanium connecting rods, titanium inlet valves, Nimonic steel exhaust valves and magnesium crankcases.

For maximum durability, a standard forged steel crankshaft from the old two-litre 911 was employed and the compression ratio was set at a conservative 6.5:1.

The turbocharger was supplied by KKK (Kuhnle, Koppe and Kausch AG). It was centrally mounted at the rear of the engine on an aluminium crossmember that formed part of the rear subframe. Exhaust gasses were diverted away from the turbo by a Garrett wastegate. Boost was adjustable via a dash-mounted switch in the cockpit.

Bosch supplied the K-Jetronic mechanical fuel-injection, twin plug ignition and single distributor. Oil pumps from the Porsche 908 were installed.

Output was initially quoted as 450bhp at 8000rpm but progress was rapid in this regard. By the middle of 1974, a Type 911/78 engine was available which produced 500bhp at 7600rpm and 405lb-ft at 5400rpm.

Despite such prodigious numbers, Porsche opted to stick with the five-speed Type 915 gearbox as fitted to the standard 1974 RSR. They knew it would be at the limit of its torque capacity but had no realistic alternative.

Other special equipment included a ZF limited-slip differential and titanium driveshafts.

BODYWORK

Visually this was the most extreme 911 yet.

Dramatic wheelarch extensions were stretched over the enormous new rims while at the rear, a custom engine lid was used to mount an elaborate F1-style spoiler on two swept pylons. The engine cover was home to a gigantic NACA duct, airflow to which was smoothed by a flush rear window instead of the standard recessed item.

By deleting the spare wheel and moving the fuel tank from underneath the front lid to inside the passenger compartment, Porsche were able to integrate a new front apron with large brake cooling ducts alongside an enormous radiator intake.

Wafer thin fibreglass was used to fabricate the front and rear deck lids, the fenders, doors and aprons.

INTERIOR

In addition to the aluminium-encased fuel tank mounted behind the front seats, the RSR Turbo came with a rudimentary new crackle-black dash and a lightweight aluminium rollcage.

WEIGHT / PERFORMANCE

Weight was initially around 820kg which had been further reduced towards 750kg by the summer of 1974.

Top speed was 193mph and 0-62mph took 3.2 seconds. With a 30/70 front-to-rear weight bias and old-school turbo delivery, the RSR was a real handful to drive.

PRODUCTION

Porsche constructed four RSR Turbos, three of which were built from scratch (R9, R12 and R13) plus one mule (R5, ’The Tank’) which was assembled from a works 1973 RSR with a standard chassis.

All four were painted silver and emblazoned with Martini graphics.

1974 LE MANS TEST

The new Porsche was first seen in public at the annual Le Mans Test on March 24th 1974. Two cars were taken: R9 for Gijs van Lennep / Herbert Muller and R12 for Helmuth Koinigg. Both R9 and R12 ran without the air-to-air intercooler which added 50bhp.

All three drivers found the handling less than perfect with too much downforce on the front wheels. Koinigg nevertheless posted sixth fastest time with van Lennep / Muller back in seventh.

Just behind the RSR Turbos in eighth spot was the brand new Ligier JS2 Maserati which was similarly a GT-based Group 5 Prototype.

Fastest overall was the Alfa Romeo 33/TT/12 of Arturo Merzario.

1974 LE MANS 4 HOURS

The Le Mans Test weekend closed with a four hour race.

Grid slots were dictated by test times but, because of absentees for the race, Koinigg (who was joined by Manfred Schurti) started fourth and van Lennep / Muller lined up fifth.

Neither of the RSR Turbos finished.

First to go was the Koinigg / Schurti machine which retired with a broken rocker arm after four laps.

Van Lennep / Muller went out after 30 laps with turbo problems.

1974 MONZA 1000KM

The RSR Turbos were then present for the opening round of the 1974 World Sportscar Championship on April 25th: the Monza 1000km.

Two of the cars were taken to Italy: R12 for van Lennep / Muller to race and R9 as a spare. The engine in R12 reportedly had around 480bhp.

Both practice days were wet which meant the Porsche was unable to use all of its power. As a result, Muller and van Lennep only qualified twelfth fastest, two spots behind the solitary works Ligier.

Race day also started cold and wet but, once proceedings got underway, the track quickly dried out.

The RSR Turbo ran like a train; it proved fast and reliable except for an extended stop when the driver’s door wouldn’t shut.

R12 eventually finished fifth overall, nine laps behind the winning Alfa Romeo Tipo 33/TT/12 of Arturo Merzario / Mario Andretti. Alfa took a famous 1-2-3 on home soil after both Matras retired from the lead.

Shortly before the end of the race, Swiss privateer, Silvio Moser, crashed into a stationary car that had been abandoned earlier on. Moser’s Lola T294 was split in two between the engine and rear bulkhead. Moser suffered serious injuries including a cracked skull and a broken leg.

Silvio Moser died on May 26th without ever regaining consciousness.

1974 SPA 1000KM

Just a few days after the race at Monza, the World Championship moved on to Belgium for the Spa 1000km (May 5th).

Alfa Romeo decided not to attend owing to a combination of the dangerous 14km track and poor starting money.

Ligier arrived with a brace of JS2s boasting further uprated Maserati engines. Porsche ran just the one RSR Turbo for Muller / van Lennep (R12).

Conditions were cold but dry.

One of the JS2s was damaged beyond repair after a crash in practice while the remaining example outqualified the RSR Turbo again. The Ligier would start fifth and the Porsche sixth.

There was a high attrition rate in the race but Muller and van Lennep soldiered on to finish third.

The car’s only problem had been the need for two new left rear tyres after the rear body panels started to rub onto the tyre’s outer edge. Once again, the turbo engine proved a model of reliability.

Victory went to the Jacky Ickx / Jean-Pierre Jarier Matra MS670C with Derek Bell / Mike Hailwood second in the Gulf-backed Mirage GR7. The solitary Ligier only lasted six laps before it blew a head gasket.

1974 NURBURGRING 1000KM

Two weeks after Spa, the next round of the 1974 World Sportscar Championship took place: the Nurburgring 1000km (May 19th). Although dubbed a 1000km race, the event was actually shortened to 750km in light of the Oil Crisis.

Porsche raced two RSR Turbos as they would do for the subsequent three events (Imola, Le Mans and Zeltweg). Muller / van Lennep were in the car they shared at Monza and Spa (R12) while the spare (R9) was prepared for Helmuth Koinigg and Manfred Schurti.

Ligier stayed away from the Nurburgring in preparation for Le Mans while Matra, Alfa Romeo and Mirage were all out in force.

During the Saturday practice session, van Lennep got it all wrong as he passed another car over the crest of Pflanzgarten. The Porsche landed sideways and before van Lennep could do anything about it, the back shot around and side swiped the barrier.

R12 was badly damaged and the mechanics had to work frantically through the night to fix it.

The circuit layout was not well suited to the RSR Turbos which were difficult to keep on boost.

Muller / van Lennep qualified twelfth fastest and Schurti / Koinigg were 14th. However, this was still appreciably quicker than the best standard 911 RSR (that of the Georg Loos team, which started 25th).

The race began under clear blue skies with Muller pushing and shoving right from the start. This continued throughout the race and both RSR Turbos tangled with various cars over the next few hours. Rivals suggested the big rear wing must have obscured the Porsche driver’s vision.

By the end, the Martini cars looked decidedly second hand. The Muller / van Lennep machine was delayed by a long session in the pits but still managed to place sixth while the Schurti / Koinigg entry finished seventh.

Jean-Pierre Jarier and Jean-Pierre Beltoise won in a Matra MS670C with Alfa Romeos second and third.

1974 IMOLA 1000KM

On June 2nd, the new Imola circuit in Italy played host to round four of the 1974 World Sportscar Championship.

Porsche entered two RSR Turbos: R9 for Muller / van Lennep and R5 for Schurti / Koinigg.

Nicknamed ‘The Tank’, R5 was one of Porsche’s works 1973 911 RSRs and had a standard chassis instead of the semi-spaceframe type used by the proper RSR Turbos.

Instead of the usual turbocharged engine, the one fitted to R5 (Type 911/78) had been modified so that the cooling fan lay flat on top of the engine like a Porsche 917. Trialled in an attempt to reduce cylinder head temperatures, it apparently gave a few extra horsepower too. The idea was to test the system at Imola with a view to running it at Le Mans.

During practice, the Schurti / Koinigg ‘Tank’ had a coming together with a Jolly Club 911 and, as a result, only qualified 23rd.

By contrast, Muller and van Lennep started sixth and the solitary Ligier JS2 was twelfth.

More problems for the Schurti / Koinigg ‘Tank’ followed when, on Saturday morning, it stopped after a few laps of unofficial practice with oil pouring from the base of its new fan housing. The Porsche mechanics set about curing the leak although, by the time the other cars lined up for the race, they were still working in the pits.

Schurti eventually got going but, soon after joining the race, he was back in the pits for another 45 minutes to have the turbo rebuilt as one of the fan blades had broken. The turbo eventually expired for good after 133 laps and R5 was not raced again.

In the sister car, van Lennep’s pace had started to slow and when he finally pitted, it was found that half the rubber was missing from the centre of his right rear tyre. The melting track surface had caused the tyres to severely blister.

R9 later started to lose gears and Muller eventually stopped with a box full of neutrals at half distance.

The Imola 1000km was won by Matra with Alfa Romeo second and third.

1974 LE MANS 24 HOURS

Off the back of a double DNF in Italy, Porsche entered two RSR Turbos for the Le Mans 24 Hours which was held over June 15th and 16th.

A brand new example (R13) was on hand for Muller / van Lennep and, following the test at Imola, this machine used the new Type 911/78 engine with its flat-mounted fan. The sister car (R12) was entered for Schurti / Koinigg.

Cast aluminium instead of magnesium crankcases were used on both cars in the interest of durability.

Also present in the Group 5 Prototype class at Le Mans were four Matras, two Mirages, a brace of Ligier JS2s and several privateer Porsche 908s. Alfa Romeo were absent.

After some early niggles, Muller qualified the new car seventh. Schurti / Koinigg were sandwiched between the two Ligiers in eleventh.

Like practice, race day was warm and sunny.

The RSR Turbos ran sixth and seventh in the opening stages before being split by one of the Ligiers.

After two hours, the Muller / van Lennep example was up to fifth despite time lost blocked in the pits.

By 8pm, the RSR Turbos were running third and fourth where they remained until 11pm when the Schurti / Koinigg entry retired in a ploom of smoke when its engine blew at full revs down the Mulsanne Straight.

Shortly before midnight, the first and second-placed Matra team were in trouble too. Bob Wollek brought the second place MS670B into the pits with a blown engine and it was out.

The solitary RSR Turbo was thus promoted to second and, by 4am, was seven laps behind the lead Matra. A lengthy stop for a replacement suspension coil cost the Porsche time. Then at 8am, the Matra’s engine started to misfire which took several stops to remedy.

Both cars needed much work over the remainder of the race but ultimately held position. The Porsche had gearbox and steering trouble while the Matra needed a late gearbox rebuild.

At times it looked like either car could win it. However, the MS670C of Henri Pescarolo and Gerard Larrousse eventually took a popular victory by six laps.

1974 ZELTWEG 1000KM

After its stellar performance at Le Mans, R13 was rested for the Zeltweg 1000km in Austria two weeks later (June 30th). Porsche instead took R9 for Muller / van Lennep and R12 for Koinigg / Schurti.

Alfa Romeo, Matra and Mirage were all present along with a brace of JS2s from Ligier.

The RSR Turbos qualified seventh (Muller / van Lennep) and eighth (Schurti / Koinigg) while the Ligiers started tenth and 13th.

The French cars initially got the jump off the grid but were quickly overhauled by the now superior RSR Turbos.

There was soon drama in the Porsche pits when Koinigg came in ten laps after he had blasted by van Lennep. Koinigg said that the gearbox was not working properly but, when the mechanics checked it, they could find no fault and so he was sent out again. However, R12 didn’t make it out of the pits before the car lost all power. It transpired Koinigg had turned up the boost to pass van Lennep and blown the turbo.

Later, Muller was hampered by a broken throttle linkage which he fixed out on the circuit. R9 then fired back up and went on to claim sixth overall behind two Matras, two Alfas and a Mirage.

Pescarolo and Larrousse made it five wins on the bounce for Matra.

1974 WATKINS GLEN 6 HOURS

Another two-week gap followed and then the teams had to be in the USA for the Watkins Glen 6 Hours on July 13th.

Mirage and Ligier skipped this event while Porsche reduced their effort to a single car for their last three races of the season.

R13 was used at Watkins Glen, Paul Ricard and Brands Hatch with Herbert Muller and Gijs van Lennep taking the wheel on each occasion.

Porsche missed the first day of Watkins Glen practice (Friday) after R13’s tail section and wheels went missing en route from New York to the circuit. When the parts turned up on Saturday, the car was found to have the wrong gear ratios and a faulty distributor.

Both were changed for the race which Muller and van Lennep started fourth behind a brace of Matra MS670Cs and a sole Alfa Romeo. The second Alfa had been severely damaged in practice.

The race took place in sunny conditions and, after two hours, the RSR Turbo was up to third.

It was then promoted to second less than an hour from the end when Mario Andretti’s Alfa Romeo dropped out. Here the Porsche stayed. Muller and van Lennep came home eleven laps behind the winning Matra MS670C of Jean-Pierre Jarier and Jean-Pierre Beltoise.

Alfa Romeo were not seen again in 1974.

1974 PAUL RICARD 1000KM

In the Paul Ricard 1000km event on August 15th, the Porsche squad had an unusually troubled race. R13 initially qualified eighth, well ahead of the Ligier JS2s in 17th and 18th.

However, van Lennep lost fifth gear in the first hour of the race and then the Porsche would not refuel properly. As the event wore on, R13 lost more gears and eventually crossed the line stuck in second. That it still placed seventh was a miracle.

Matra took another one-two with Mirage third.

1974 BRANDS HATCH 6 HOURS

Porsche did not plan to attend the Kyalami 6 Hours in early November so the Brands Hatch 6 Hours on September 29th would be the last appearance for the RSR Turbo.

With no Alfa Romeos or Ligiers present, the premier class was a little thin: just Porsche, Matra and Mirage.

New Dunlop tyres for the Porsche were thought to be good for a second a lap but the tight and twisty nature of the English circuit meant the RSR Turbo was difficult to keep on boost.

Muller and van Lennep started tenth behind a number of two-litre Group 5 Prototypes which were much better suited to the circuit.

The Porsche drivers steadily rose up the leaderboard and looked set to finish fourth with just 45 minutes to go. However, soon after Herbert Muller went out for his final stint, he went off track when lapping a slower vehicle. The Porsche’s front apron broke off in the process which resulted in a dramatic reduction in downforce.

Muller pitted next time round but a replacement part could not be fitted in time so he was told to finish the race. This was not so easy as, every time he snatched fifth gear, the rear downforce and acceleration lifted the front wheels clean off the track.

R13 eventually finished fifth while Matra took another one-two.

END OF THE 1974 SEASON

Thereafter, the RSR Turbos were retired from competition duty.

One week after the race at Brands Hatch, Helmuth Koinigg was killed racing for Surtees in the United States Grand Prix at Watkins Glen.

Although not gunning for the title, Porsche finished third in the 1974 World Sportscar Championship with 68 points. Alfa Romeo were fourth on 65. Matra were clear winners on 140 with Mirage second on 81.

Owing to a lack of manufacturer support, the FIA postponed the introduction of their Group 5 regulations until 1976.

Although they did not officially race in 1975, Porsche continued to develop their turbocharged 911s and also created a new top flight turbocharged Prototype for 1976: the 936.

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com

Guide: BB Porsche 911 & 911 Turbo (930) - a Historical & Technical Appraisal

<<<TUNER PORTAL
<<<PORSCHE PORTAL

BACKGROUND

BB was established in 1973 and initially based at an ex-BMW workshop in Frankfurt.

The firm’s custom body, paint, engine and interior programmes saw BB quickly establish itself as the premier destination for modified Porsches.

Founded by brothers Rainer and Dieter Buchmann, it was three years after the company was set up that it would come to international prominence.

The turbocharged Porsche 930 Coupe had been launched in February 1975, but Porsche did not intend to manufacture a Targa version principally because they believed demand for the Coupe would not greatly exceed the 400 units required for homologation into the Group 4 racing category.

BB 911-30 TURBO TARGA

Unexpectedly, the 930 was a commercial success and, in late 1976, BB launched their 911-30 Turbo Targa conversion.

The Turbo Targa programme cost DM68,000. It saw a donor 911 Targa (not included in the price) completely re-manufactured with genuine Turbo parts to include fenders, spoilers, suspension, brakes, fuel system and electrics.

The floorpan and roof were strengthened and a new Turbo engine and transmission were installed.

16-inch Fuchs wheels and Pirelli P7 tyres were also fitted.

What enhanced BB’s pioneering reputation were state-of-the-art electronic options and the enormous degree of personalisation afforded to customers - ticking every box could more than double the list price of a standard 930.

In many ways, BB’s bespoke tailoring programme picked up the slack left after the demise of traditional coachbuilders when inflexible mass production techniques meant truly individual creations all but disappeared.

Porsches that went through the BB workshop could be enhanced with a telephone mounted discreetly in the dash (DM18,000), Scheel sport seats (DM1000), electric windows (DM1800) and velvet upholstery (DM3000).

Combination Hi-Fis were also popular. The typical BB system used a Blaupunkt Berlin radio receiver, Uher cassette player, 16 Pioneer speakers and an amplifier (DM4400).

Fully equipped, the list price for a BB Turbo Targa conversion was in excess of DM100,000 plus of course the DM36,000 it cost for a brand new entry level 911 Targa donor.

Weight was 1335kg compared to 1210kg for the 930 Coupe.

Performance was only marginally affected: 0-62mph required 5.8 seconds and top speed was 153mph.

By the end of 1976, several Turbo Targas had been manufactured, one of which was the famous ‘Polaroid’ press car built as a rolling showcase for BB’s talents. This vehicle incorporated nearly all the available equipment and starred in the 1980 film “Car-Napping”.

Production continued throughout 1977 with more options becoming available. These included US-specification bumpers and a normally aspirated Super Carrera Targa that featured Turbo-style bodywork without the forced induction engine. Both were introduced in March 1977.

By June 1977, BB had completed a de-spoilered Turbo Targa and, in 1978, they offered the new 3.3-litre Turbo engine along with BBS rims.

BB 911-30-28 TURBO / TURBO TARGA

Once Porsche introduced the flat nose 935 racing car, it was inevitable that customers would start to request road-going 911s equipped with similar front-end styling. Alongside DP (who made lightweight shells for the Kremer racing team), BB were among the first companies to offer flat-nose bodywork.

Whereas DP housed the driving lights below the front bumper (just like the factory 935), BB installed retractable Porsche 928 units on the front wings. By doing so, they instantly created one of the most stunning custom cars of the late 1970s. The all-steel ‘28’ headlight conversion was available from May 1978 and in isolation cost DM7500.

By this time, the basic cost of a brand new Turbo Targa conversion with all bells and whistles including the latest 3.3-litre engine and 928 front styling was DM162,500. Included was a 370bhp motor with the boost turned up to 1.1bar.

Customers were of course able to select individual upgrades for their vehicles. BB now offered BBS alloy wheels with coloured centres and polished rims (DM3250), a large front oil cooler (DM4500) and limited-slip differential (DM850).

Interiors could be enhanced with leather-covered seats, dashboards and speakers plus velvet carpet throughout including the boot (DM3950). There was also an electric front seat option (DM2200) plus air-conditioning (DM2600) and a chilled bar mounted in the rear seat (DM1500).

Other enhancements included a Sony colour TV and amplifier (DM2650), Citizen 40-channel radio telephone with 150-watt amp (DM4000), a four speaker stereo (DM1300), digital clock and tachometer (DM1200) and an adjustable boost toggle with pressure display (DM2000).

Security-conscious buyers were able to specify an alarm (DM700), a safety deposit box connected to the alarm system (DM850) and even a concealed storage compartment for a pistol (DM380).

A rear wiper and heated electric mirrors were among the more prosaic upgrades available.

The first 911-30-28 Turbo Targa was ordered by Curacao casino owner, Ortega Ramirez, who requested BB install practically every conceivable option to his car. However, the further customisation afforded to this Midnight Black example (such as extensive gold plating plus monogrammed seats and floormats) forced the price up to an astonishing DM250,000.

The ‘28’ headlight conversion became one of BB’s most popular options and spawned a host of copycats from the many new firms that jumped on the super-tuning bandwagon. Even Porsche themselves offered a limited edition 965 Turbo S with 928-style headlights many years later.

More developments came on stream during the course of the next few months.

BB’s Targa version of the Porsche 928 debuted at the Frankfurt Motor Show in 1979.

At the same time, directionally slotted disc wheel trims designed to aid brake cooling were introduced. They were followed by a Wide Body option in 1980 which saw all four fenders and both doors re-shaped and made around 100mm wider on each side. When specified, re-profiled door skins housed a prominent Ferrari-style engine intake. The Targa roof option got a T-bar to increase rigidity.

DINFOS

Soon afterwards, BB’s state of the art digital information system (DINFOS) was launched. Functions such as engine revs, speed and oil and water temperatures were displayed on the fascia in red LEDs. A computer mounted on the centre console could record anything from acceleration time, fuel consumption, average speed, time spent waiting at traffic lights and more.

Famously, Walter Wolf had the last of his custom Lamborghini Countachs equipped with DINFOS.

By the early 1980s, BB began to focus increasingly on Mercedes-Benz. The firm also tried to break into the mainstream market with Volkswagen.

Precisely how many 911-based conversions were completed before BB went out of business in 1986 remains unknown.

The bulk of production was split between Europe and the Middle East.

Text copyright: Supercar Nostalgia
Photo Copyright: BB

Guide: Porsche 911 2.7 Carrera Turbo - a Historical & Technical Appraisal

<<<PORSCHE PORTAL

BACKGROUND

As the Porsche 911’s rivals were mostly larger-engined models, by the early 1970s it was obvious that more power would have to be extracted from the air-cooled Flat-6 engine if it was to remain competitive on road and track.

Substantially enlarging the engine was not an option as the 911’s layout already had its handling idiosyncrasies: to add more weight behind the rear axle would only exacerbate the issue.

Instead, the solution was turbocharging, something Porsche became an early proponent of in motor racing.

After dominating the Can-Am championship with the spectacular forced induction 917/10 and 917/30 between 1972 and 1973, Porsche switched focus and campaigned a batch of experimental 911 Carrera RSR Turbos throughout 1974.

These Martini-backed 2.2-litre test beds ran in the prototype class of the World Sportscar Championship which allowed the utmost freedom of development. The successful 1974 campaign provided Porsche with much of the knowledge they needed to release a forced induction road car into circulation.

The first road-going 911 Turbo was not the familiar 930 that entered production in February 1975. Nor was it the engine-less prototype that had appeared at the Paris Motor Show in October 1973.

Instead, it was a one-off narrow-bodied mule that was subsequently gifted to Ferry Porsche’s sister, Louise, on her 70th birthday in August 1974.

Built on chassis 9115600042, this 2.7 Carrera Turbo also pre-dated the prototype 930 that was shown in almost production-ready guise at the Frankfurt Motor Show in October 1974.

CHASSIS

It was based on a standard early 1975 model year Carrera 2.7 equipped with the usual all-round independent suspension, ventilated disc brakes and 15-inch Fuchs alloy wheels (6-inches wide at the front, 7 inches wide at the rear).

ENGINE / TRANSMISSION

Although precise details of the original 2.7-litre engine installed in the car were never publicly revealed, we do know this experimental unit had a single turbocharger and Bosch K-Jetronic with the CIS injection system as opposed to the MFI arrangement found on the stock 2.7 Carrera.

Displacement was unchanged from the normally aspirated version: 2687cc thanks to a bore and stroke of 90mm and 70.4mm respectively.

The compression ratio, power output and torque rating were never published but approximately 240bhp was quoted by factory insiders.

This was transmitted through a four-speed 915 gearbox with special ratios and a limited slip differential.

The combination of massive torque and the potential to strip gears meant a factory five-speed 911 Turbo wasn’t offered until the 1989 model year. By this time, the 915 ‘box had been replaced with Porsche’s uprated G50 unit.

BODYWORK

From the outside, nothing suggested the 2.7 Turbo was anything out of the ordinary. It used a standard narrow body pre-930 shell which was still badged as a Carrera.

The silver prototype came with headlight washers and a driver’s side door mirror.

WEIGHT / PERFORMANCE

Weight was 1084kg and, thanks to an excellent power-to-weight ratio, the car would have delivered similar performance to a normally aspirated 2.7 Carrera RS.

INTERIOR

Initially, the black interior only sported a non-standard 10,000rpm tachometer.

MODIFICATIONS

After chassis 5600042 had completed its development programme, Porsche carried out a number of modifications ahead of the car’s handover to Louise Piech.

The changes included new red leather upholstery with red and blue MacLaughlan tartan seat centres and matching door cards. Fresh red carpet and a black headliner were installed along with a Blaupunkt four-speaker stereo plus electric antenna and a voice recorder.

Outside, tartan side decals matched the seat centres.

Soon afterwards, front and rear spoilers were added whilst, for practicality, the experimental engine was replaced with a standard three-litre turbocharged motor from the 930.

SUBSEQUENT HISTORY

In this configuration, the car was presented to Louise Piech on August 28th 1974.

Chassis 5600042 was retained by the Porsche family and now resides in the factory museum.

Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com