the triumphant debut last year of its 2649cc turbo engine, Porsche immediately started on the development of its new Group C car: the Porsche 956 under its technical director Norbert Singer. The flat-six, four-valve engine had a combined air-cooled block, and water-cooled heads. For qualifying, at 1.2-bar boost, it would generate 615 bhp, wound down to 1.1-bar (580 bhp) for race-pace and fuel economy. The aluminium hull was Porsche's first monocoque chassis, and with assistance from Dornier, had its aerodynamics tested in a wind-tunnel. This led to the engine being tilted at an angle. Also the company's first ground-effect car, the langheck version generated over three times as much downforce as the Porsche 917 model from a decade earlier. A completely new 5-speed gearbox was installed, replacing the CanAm 4-speed 'box used the year before. The project took only 9 months and in March, test driver Jürgen Barth was doing track runs and its first outing was at the Silverstone round. The team was nervous on fuel consumption if the competition chose to push them to race to keep up. The team had a computer in the pits and digital flow meters in the cars to give them an edge in calculating the fuel consumption. Three cars were ready just in time, run by new team manager Peter Falk. Jacky Ickx was back out of retirement and a full-time works driver again with Derek Bell as his co-driver. The second car had Jochen Mass and Vern Schuppan while the one-off third car had Barth, Hurley Haywood and Al Holbert. Ford was the other bulk manufacturer to take on Porsche. The new C100 model (named as it would be 100 cm high) was based on an aluminium monocoque design from Len Bailey. The first chassis was built by Hesketh Engineering while Alain de Cadenet got two more made, debuting at Brands Hatch in 1981. The project was then transferred to Ford Deutschland, working with the German Zakspeed racing team. Ford had engaged with Cosworth, to develop the famous DFV 3-litre Formula 1 engine for the car. Two versions of the new DFL V8 came out: a 3.3-litre and a 540 bhp 3.96-litre model. It was the latter that was put into the C100. Two cars were entered with Manfred Winkelhock and Klaus Niedzwiedz in one of the De Cadenet chassis, while a new Zakspeed chassis (with design updates by Tony Southgate