Porsche 956/962 remembered

The decline of Group 6 and the growth of Group C saw the emergence of what is today widely regarded as the most entertaining and successful era in modern motorsport. Group C ran from 1982 to 1992, a decade that saw some of the most innovative and exciting engineering solutions to race car development imaginable. In this feature, Porsche 956/962 remembered, we look at some of the significant achievements made by this racing model.

Towards the end of the 1970s a lack of manufacturer enthusiasm to develop new cars for the existing Group 5 and Group 6 categories loomed. In 1978, Jürgen Barth, who was the President of BPICA (Bureau Permanent International de Constructeurs des Automobiles) along with the other committee members, began to thrash out the framework for a new set of rules to come into effect in 1982, replacing the Group 5 and 6 categories. It quickly became apparent that what the FIA and the manufacturers wanted, was to return to a flagship sports car prototype formula that would once again draw the crowds. For Porsche, having Barth as President of this body was extremely useful in that he and his boss, Norbert Singer, could discuss what car Porsche might build if these rules came into play. Broadly, Porsche’s intention was first to enter their new Group C racers as a full works team, and then to follow this by supporting approved customer teams with the new racer.

The manufacturers represented on the BPICA panel all had their own plans and agendas, but progress towards an agreement was made during the 1978 and 1979 seasons. This allowed for cars to be constructed with a free chassis and engine, although the engine had to be sourced from an existing production car. How convenient this turned out for Porsche at the time as their production engine for the new racing series had its origins in the standard 3.0-litre 930 turbo road car, and this unit could be easily adapted to suit the new Group C regulations.

From the outset, BPICA determined to create a set of rules that were consumption-based, as this created a level playing field. The Group C regulations defined a car as a two-seater intended only for competition purposes but engines were not limited by capacity, configuration or induction system, provided they were based on a recognised production unit. Klaus Bischof, chief technician in charge of the team’s number two car, explains, “[Engine] capacity was not a ruling you know, it was the crankshaft housing that had to be from a homologated production car. For us this was the 911.”

Type 956 design and development

Under the watchful eye of Norbert Singer, the new Group C Porsche Type 956 began to take shape. The step up from the 936 to the new 956, besides the obvious differences in upper body form, lay also in the under-car developments and chassis construction which was no longer a spaceframe, as in the 936, but an aluminium chassis fitted to a monocoque. With this new breed of racer, Porsche entered the realms of a super sports racing car with a full ground effects body with chassis design carried out by Horst Reitter.

It had become clear that a tube frame chassis would not meet the current safety standards specified for the new Group C racers and this prompted Porsche to explore the fabrication of a monocoque chassis. Porsche racing driver and engineer, Jürgen Barth, explains, “It was clear that a tube frame chassis was not as strong as a monocoque in a crash, but it was the first time that the factory had made a monocoque and so it was quite a challenge for Mr Singer, but it worked out quite well I think.”

An official proposal was drawn up at the beginning of 1981 according to Singer that roughly laid out the dimensions of the car, and which looked into the feasibility of constructing a car based on a fuel consumption ruling. “For a manufacturer like Porsche, this was the most challenging thing because this is an interesting challenge for a manufacturer, not just to make a race car and to go racing, but it was also a technical challenge,” Singer explained.

The Group C rules stipulated that the underfloor of the car, measured as that area behind the front wheels and ahead of the rear wheels, should be a ‘solid flat, hard, rigid and continuous surface’. On this surface, a ‘rectangle of 1000 mm measured along the transverse axis, and 800 mm measured along the longitudinal axis’ could be inscribed – in other words a flat plate with one aero channel running on either side – but the rules did not stipulate what should happen behind this point, except that the channel should be an integral part of the chassis/body and not be flexible or movable in any way.

The 956 was a good-looking car, right from the start. “In December ’81 we showed a one fifth scale model at a Porsche Cup party, but on that model the floor was [completely] flat because when all the people and the press saw it, they turned it over and looked for the tunnels underneath to see the ground effects, but they didn’t see anything because there was nothing there. We had hidden that because I had said this was the secret of the car which we didn’t want to show because the others would copy it,” Norbert Singer explained.

Key to Porsche’s dominating performance throughout 1982 was the team’s attention to detail back at the workshop in Weissach, as well as at the various circuits where they raced. This policy paid off as the Porsche 956 scooped up four victories in the World Endurance Championship in 1982, which included: Le Mans 24-Hours (June 19/20), Spa 1000km (September 5), Fuji 6-Hours (October 3) and the Brands Hatch 1000km (October 17). Non-championship victories that year included the 200 Miles of Nürnberg (Norisring, June 27) and the popular Kyalami 9-Hours (November 16) held in Johannesburg, South Africa.

The Porsche was dominant in its first three years, until that is, it was replaced by the 962 which was just more of the same thing. The 956 was not allowed to race in the USA, which of course is where Porsche wanted to make a big impact, and the reason for this were the driver’s feet, which were ahead of the front axle line. No problem for Porsche, they just extended the wheelbase, and this brought the driver’s feet back behind the safety line of the front axle.

The 956 and 962 constitute such a huge subject in the world of Porsche, as these two models dominated for a decade, and even though other manufacturers eventually pushed Porsche off the top step of the podium, they were always a threat at the head of the field. That said, a Porsche 962 won the Daytona 24 Hours in 1989 and again in 1991. Right up until 1993, the 962 was a regular visitor on the podium in the European Interserie.

Put simply, the achievements of the Porsche 956/962 have not been equalled in the world of motorsport since those heady days of the 1980s. This model (the 956 and 962 are considered one and the same model, if you talk to the folk at the Porsche factory) will go down in history as the most successful racing prototype ever.