Guide: Porsche 959
Background
Porsche’s 959 was the ultimate road-going evolution of the 1980s 911.
Conceived as a Group B homologation special, the first 959 prototype was unveiled at the Frankfurt Motor Show in September 1983.
Along with Groups A and C, Group B formed part of a new regularity framework introduced for the 1982 season.
Group B was designed to replace both the existing Group 4 and Group 5 categories and had a minimum production requirement of 200 cars over a twelve month period. Group B machinery would be eligible for both circuit racing and rallying.
By contrast, homologation into Group A required 5000 units. Qualifying cars were eligible for rallying and touring car racing.
Group C was for out-and-out prototypes. It had no minimum production requirement although a fuel efficiency limit of 600-litres per 1000 kilometres was introduced.
1982 was a crossover year during which machinery from the old categories could race alongside those from the new classes. From 1983, all participating cars would have to conform with the latest regulations.
By the time the prototype 959 was displayed at Frankfurt in 1983, Group B rallying was really starting to take off.
However, as a category for circuit racing, it never captured the imagination of manufacturers; the only Group B entries for the 1983 World Sportscar Championship were old BMW M1s and Porsche 911 Turbos, both models having been re-homologated into the new category to boost participation levels. These cars typically trailed round at the back of the field behind hordes of much faster Group C entries.
While Group C grids continued to expand over the next twelve months, it became obvious that Group B racing was effectively dead in the water.
Nevertheless, development of the 959 continued.
A trio of 911-engined 959 prototypes were used on the 1985 Paris-Dakar Rally and, later that year, an almost production-ready 959 was displayed at the Frankfurt Motor Show.
Porsche then entered three proper 959s for the 1986 Paris-Dakar where they finished first and second.
A solitary track version (the 961) was also assembled for an attack on the 1986 Le Mans 24 Hours where it contested the IMSA GTX category.
Unfortunately, Group B was effectively killed off in May 1986.
Following a number of driver and spectator fatalities in rallying (where the cars had become unbelievably powerful over a very short space of time), the FIA announced the category would be banned from 1987.
At this point, it became obvious the 959 would never contest any major championship.
Instead, the model would serve as a limited production flagship available to Porsche’s wealthiest customers.
As opposed to being built at Zuffenhausen, the 959 was produced at the Baur coachworks in Stuttgart where the process was overseen by key Porsche staff.
Chassis
Although derived from the pressed steel bodyshell of series production 911s, the 959 chassis featured a suitably reinforced centre-section with longitudinal side members and an integral roll cage. A Nomex floor was used instead of steel.
Unlike the 911 (which used a MacPherson strut / semi-trailing arm suspension layout), the 959 incorporated double wishbones with two telescopic dampers per wheel: one for height regulation and the other for shock absorption.
Ride height and stiffness could be electronically adjusted from the cockpit. The driver was given a choice of soft, medium or hard settings. At speeds above 100mph, the dampers automatically adjusted to the stiffest setting.
Another new feature was full-time variable four-wheel drive which offered up to a 50:50 torque split in slippery conditions through to 20:80 under hard acceleration in the dry.
Drilled and ventilated brake discs were fitted to each corner along with four-piston aluminium calipers. The discs had a 322mm diameter at the front and 304mm diameter at the rear.
Unlike many super high performance cars of the era, Porsche did install an anti-lock brake system on the 959.
The 17-inch hollow-spoke magnesium alloy wheels were brand new. They measured 8-inches wide at the front, 9-inches wide at the back and were shod with Dunlop Denloc run flat tyres.
A 90-litre fuel tank was installed underneath the front lid.
Engine & Gearbox
Group B regulations limited engines to four-litres and applied a 1.4 equivalence for turbocharged motors. This meant any forced induction engine had to displace less than 2857cc.
Porsche settled on 2847cc thanks to a bore and stroke of 95mm and 67mm respectively.
The all-alloy Type 959/50 Flat 6 engine was a development of the 956 Group C powerplant.
Air-cooling was used for the cylinders and water-cooling for the four-valve DOHC heads. The con-rods were titanium, the pistons were forged alloy and each cylinder was lined with Nikasil carbide.
Two sequentially mounted KKK turbochargers were installed with just the small turbo coming on stream at low revs before the larger one kicked in further up the rev range.
The engine utilised dry-sump lubrication and an 8.3:1 compression ratio. Digital fuel-injection was courtesy of the latest Bosch Motronic 2.1.
In this configuration, Porsche quoted output figures of 450bhp at 6500rpm and 369lb-ft at 5000rpm.
Transmission was via a brand new six speed manual gearbox and twin-plate clutch.
Bodywork
Although unmistakably 911-derived, only the 959’s cockpit profile was shared with its little sister.
Wind tunnel-honed, the 959 had a drag coefficient of just 0.31 compared to 0.4 for the 911 Turbo.
Body panels were manufactured from Kevlar with the exception of the doors and front lid (aluminium) and the bumpers (polyurethane GRP composite). The use of advanced composite materials led to a far more complex production method than any previous Porsche road car.
To improve aerodynamics, the 959 had an extended nose with headlights mounted under clear covers. Its bulbous wheelarches were connected by a dramatic sill extension and each rear fender was home to a discrete cooling intake.
The back end was entirely redesigned. Extended like the front, it featured a lift-up engine cover with integrated basket handle spoiler. Standard 911 tail lights were joined by a familiar reflective panel that also housed the fog lights and a large Porsche script.
Interior
In the cockpit, there was relatively little to distinguish the 959 from Porsche’s other rear-engined models; aside from a redesigned forward section of the transmission tunnel (which now incorporated switchgear for the suspension settings), the interior fixtures and fittings were imported from the 911.
Some discrete changes were made to the instrumentation which relayed information about the suspension settings, drive programme (dry, wet, snow or difficult terrain), torque split and tyre pressure.
Sports seats were standard equipment but the backs and bases were uniquely upholstered with white, silver and grey inserts. Most 959s were completed with matching rear seats.
Air-conditioning, central locking and electric windows and mirrors were standard.
Weight / Performance
In this configuration, Porsche quoted a weight of 1350kg and 0-62mph time of 3.9 seconds.
The 959’s top speed of 197mph made it the fastest production car in the world at the time.
Options
Options included heated seats, an alarm and white or body coloured wheels instead of silver.
Customers could choose from a limited range of exterior colours (silver, red, white, black, anthracite and garnet) although a couple of VIP clients were able to purchase 959s in other shades (one Middle Eastern customer ordered seven cars in seven unique colour schemes).
959 Sport
The standard 959 was referred to as the Comfort version. A Sport option was also available.
The 959 Sport was a lighter, more powerful derivative stripped of several luxuries and electronic gizmos.
Conventional suspension replaced the variable dampers and electronic ride height system.
Modified turbos were fitted which took output from 450bhp to 508bhp at an unchanged 6500rpm. The torque rating was also improved (from 369lb-ft at 5000rpm to 414lb-ft at 6450rpm).
Fabric trim replaced leather and the air-con, electric windows, electric mirrors and central locking were deleted.
A leather-covered roll cage was an option.
Weight was cut by 100kg (to 1250kg), top speed rose to 211mph and the 0-62mph time dropped to 3.7 seconds.
Production
The first 959 was delivered to Wolfgang Porsche in April 1987.
At DM 431,500, the car’s list price was less than half its build cost which was one of the reasons Porsche chose not to try and homologate the 959 for sale in the USA. Had Porsche been forced to fulfil its American orders at the original quoted price of $250,000, the firm’s losses would have been even greater.
By failing to federalise the car, Porsche were legally able to cancel these orders and return customer deposits.
Production continued until June 1988.
1992 Production
There were still half a dozen or so unfinished 959 chassis left at the factory and, in 1992, Porsche were approached by a VIP customer from the Far East who commissioned their completion at a price of DM 747,000 each.
These cars were assembled at Zuffenhausen instead of Baur.
End of Production
In addition to 37 pre-production prototypes, Porsche built 284 959 Comforts and 29 959 Sports all of which were left-hand drive.
Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com
