1983 Porsche 956 C Coupé

The potential of the 956 unfolds. Porsche again wins the World Endurance Championship, Jacky Ickx secures his second consecutive world championship title. Twelve 956 vehicles are delivered to private motorsport customers. Bob Wollek not only wins the European Endurance Championship in a Joest Racing Porsche sportscar but also takes overall victory at the Deutschen Rennsport Meisterschaft (German Racing Championship), for which the Frenchman is again rewarded with the Porsche Cup as the most successful private driver. In Japan, Australia´s Vern Schuppan secures the Group C Drivers‘ Championship in a 956. The manufacturers‘ title goes to Porsche.

In the United States Wayne Baker claims the IMSA GTO Championship in a Porsche 934, whilst Porsche’s US sports boss Al Holbert collects the GTP category title driving a March Porsche featuring 956 technology.

At the Le Mans 24 Hour race Hurley Haywood, Al Holbert and Vern Schuppan drive the works 956 with starting number three to victory ahead of team mates Jacky Ickx and Derek Bell. Whilst the new works driver Stefan Bellof together with Jochen Mass retire in the third works 956 with engine damage, Porsche customer teams secure eight of the top ten places, with Philippe Alliot, Mario and Michael Andretti carrying off third place in their Kremer Porsche. Only ninth position goes to Peter Sauber´s BMW team.
At the Geneva Motor Salon in April the new Formula 1 engine is presented: the TAG Turbo – made by Porsche (internal code: TTE P01 V6). The V6 with an 80 degree cylinder bank angle, developed by Hans Mezger, is unusually light and compact. With all accessories the vehicle weighs 150 kilos. Bore: 82 mm, stroke 47.3 mm, displacement 1,499 ccm. Porsche states the performance of the engine built for the McLaren team as ca. 600 hp at between 10,000 and 11,500 revolutions per minute. Initial tests in the 956 take place on Porsche’s test circuit in Weissach – shortly afterwards the new six cylinder is implanted into a McLaren chassis for the first laps in Weissach – at the wheel sits Porsche engineer Roland Kussmaul.
On 28 August McLaren pilot Niki Lauda races the new engine in Zandvoort (NL) for the first time. At just the fourth race – at the South African Grand Prix in Kyalami – Lauda is swift enough in his MP4 1/E to hunt the leading Patrese from second place, only to be stopped by a problem with the electronics. The engine now delivers 700 hp. Over winter Porsche continues developing at high speed.

956 C Coupé

On the engine side Porsche pushes ahead with further developments – the FIA, the sport’s governing body, announces: From 1984 only 510 litres are allowed for a 1,000 kilometre race instead of the currently permitted 600 litres of fuel. Porsche introduces an electronic fuel injection, increases the compression to 8.5 and achieves considerably better performances. One of the works cars featuring the new technology grinds to a standstill in Le Mans. But the factory – and hence the customers – are prepared for the following year. At this stage no one can know that FIA will back out in 1984, sparking off a furore.

Technical Specifications
Engine:	Six-cylinder four-stroke, horizontally opposed engine, dry sump lubrication
Power:	640 bhp (470 kW) at 8.200 rpm
Displacement:	2.649 cc
Fuel system:	Electronic fuel injection (Motronic Sport), 99-litre safety fuel tank
Transmission:	Five-speed fully synchronised transmission with oil cooling, transmission ratios can be specified, single-plate dry clutch
Chassis:	Aluminium monocoque, riveted with integrated safety bar, Kevlar body reinforced with carbon fibre Front axle: double wishbone with titanium springs, Bilstein shock absorbers fitted externally Rear axle: double wishbone with titanium springs, Bilstein shock absorbers fitted internally Hydraulic dual-circuit disc brake with twin pliers and ventilated by wheel carriers
Dimensions and weight:	Wheelbase 2.650 mm length 4.800 mm width 2.000 mm weight 820 kg
Performance:	Top speed in excess of 350 km/h (217.5 mph)

Source:
http://www.porsche.com/middle-east/_yemen_/motorsportandevents/motorsport/philosophy/history/racingcars/1983-956ccoupe/