Guide: Porsche 911 3.0 Turbo (930)
Background
The 2.7-litre Carrera RS introduced for the 1973 model year was Porsche’s first 911-based homologation special. It 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. This enabled the model to go racing in Group 3 with its 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.
At the same time, Group 5 was switched from a three-litre Prototype class to one for Special Production Cars.
The Group 5 Special Production Car class was for more heavily modified vehicles of the type 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 production car upon which they were based 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 were 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 commercial hit. It was actually so popular that Porsche made it 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.
Chassis
930s were based around the 911’s standard steel unibody chassis.
Suspension was lifted from the 1974 model year 3.0 Carrera RS. At the front it comprised 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 anti-roll bars 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.
The forged light alloy wheels were supplied by Fuchs. 15 x 7-inch rims were fitted at the front and 15 x 8s at the back. They were normally shod with Dunlop or Pirelli tyres.
Compared to the 1975 model year 911 2.7 Carrera, track was 60mm wider at the front and 108mm wider at the rear.
Engine & Gearbox
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 camshaft 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.
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.
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 massive rear spoiler.
A matt black chin spoiler was also installed along with an adhesive satin black stone guard in front of each rear wheel.
Satin black window frames were standard but chrome-plate was a no cost option.
The big arches and spoilers gave the 930 a purposeful new look. Although it lacked the visual drama of a Ferrari Berlinetta Boxer or Lamborghini Countach, for many customers, that was part of its appeal. The 930 packed a supercar punch in a relatively discrete package that was practical enough for 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 had half leather sports seats with tartan fabric centres and door panels trimmed to match.
The small diameter three-spoke steering wheel was trimmed 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 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
Customers could optionally specify a ZF limited-slip differential, rear fog lights, air-conditioning, a sunroof and a centre console.
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.
Launch & Prototypes
An engine-less 930 mock-up (chassis 911 330 0157) was displayed at the Frankfurt Motor Show in October 1973. However, this silver and white-striped prototype retained many 3.0 RS features including bumpers, fenders, wheels and seats.
A narrow-bodied 911 2.7 Carrera Turbo prototype was built in early 1974 (chassis 911 560 0042). After serving as a development car, it was refurbished and gifted to Ferry Porsche’s sister, Louise, on her 70th birthday in August 1974.
A more or less production-ready 930 was unveiled at Frankfurt in October 1974. It featured cross-drilled and ventilated discs from the 917. For production, Porsche switched to the regular Carrera 3.0 arrangement citing question marks over long-term reliability.
Production
930 production started in February 1975 (on the H-series platform). The model went on public sale shortly afterwards.
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 variant was in production.
Just 284 H-series 1975 model year 930s were built, all of which were left-hand drive.
Among the most famous of these was chassis 930 570 0208 ordered by Austrian conductor, Herbert von Karajan. A serial Porsche customer and marque VIP, von Karajan’s silver 930 came direct from the factory with a tuned engine, roll cage, chrome window frames and elaborate Martini Turbo graphics. It featured on the front cover of his best-selling Famous Overtures album and was later further uprated with Cibie spot lamps and racing seats.
1976 Model Year I-series
The 1976 model year 930 (production of which began in September 1975) was based on the revised I-series platform.
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.
The rear spoiler’s secondary engine cooling grille was made considerably larger.
Also noteworthy was a new six-year anti-corrosion warranty that far exceeded the guarantee given by any other high performance manufacturer of 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 Turbo decal kit.
USA Version
North American customers were supplied with a US-legal 930 for the first time. 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.
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). The 16-inch Fuchs alloys and centre console became standard.
The tachometer now housed a boost gauge, twin fuel pumps were fitted, the synchromesh on first and second gear was revised and the differential assembly was 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 followed a unique ‘Martini Turbo’ that was produced for the British Motor Show in October 1976. The 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.
1975 model year H-series, Type 930/50 engine, 284 examples built, VIN range 930 570 0001 to 0284
1976 model year I-series, Type 930/50 engine, 644 examples built, VIN range 930 670 0001 to 0644
1976 model year I-series USA version, Type 930/51 engine, 530 examples built, VIN range 930 680 0001 to 0530
1977 model year J-series, Type 930/52 engine, 695 examples built, VIN range 930 770 0001 to 0695
1977 model year J-series USA version, Type 930/53 engine, 727 examples built, VIN range 930 780 0001 to 0727
Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com
