When the final Group C regulations were published in October 1981, the Porsche 956 study was in full swing since June. In Weissach (Porsche R&D Center), we already had some features since Jürgen Barth, head of customer competition at Porsche, was also president of the FIA Sports Systems Commission. He is the one who defines the dimensions of the Group C front mirror, going to test 917 at the Porsche museum! Leaving the nass chassis, project manager Norbert Singer believes it is time to move on to the monocoque. He chooses aluminum, which is easier to understand than carbon, which has recently appeared in F1. After taking advice from aeronautical company Dornier, Horst Reitter designed a chassis, whose 2650 mm long wheel did not prevent the shell from proving to be 80% more rigid than the 936 tubular. Norbert Singer maintained aerodynamics, in the College wind tunnel. Stuttgart University. Two rear bonnets are available, along with the long one intended for the Le Mans circuit. 956 being the first Porsche to benefit from the ground impact, the Singer must be aware of this technique and, in order to provide back power, the power unit is elevated.
The engine is the only proven feature of 956 since it was installed at 936. It is a 6 flat that crankshaft is taken from 911. In its 1981 version, Type 935-76 increased to 2650 cm3. Two KKK turbo blows at 1.4 bars enable it to reach 620 hp in the race