Opel Ascona 400R

First shown at Frankfurt in September 1979, the Ascona 400 was a homologation special sold only to make it eligible for rallying's Group 4 category.[9] The Ascona 400s were built at General Motors' plant in Antwerp. The 1980 world champion Walter Röhrl took the rally car to victory and won the World Rally Championship drivers' title in the 1982 season.

The car was developed by Opel alongside the Manta B 400 model which consisted of the same changes. Irmscher and Cosworth were hired as partners for the project, Cosworth to deliver a 16 valve double cam crossflow head for the engine, and Irmscher for the exterior and interior styling. Cosworth delivered the heads to Opel and Opel soon discovered a major mistake. The plan was to use the 2.0 litre engine block but this did not produce enough power. Time was running out and Opel badly needed to do something. Opel took the 2.0E block, installed forged pistons, different connecting-rods, and forged crankshaft with 85mm stroke. The result was a 2.4 litre engine. The 2.4 litre engine gave rise to some massive power outputs using the 16 valve head. The street versions of the 400 therefore came with 144 hp (107 kW) engines, using the Bosch fuel injection of the Manta GSi and GT/E series. However, in race trim they were delivered putting out 230 hp (172 kW), which could be improved further to 340 hp (254 kW), while still using normally aspirated engine components.

Irmscher delivered the rally trim for the exterior. Large and widened wings, light weight hood, front wings, rear boot lid and doors were also installed.

By 1984, the Audi Quattro appeared more powerful than ever and the Ascona 400 was rendered obsolete. But the Ascona 400 still has some remarkable records. The Ascona 400 was the last rear wheel drive rally car to win the drivers' world championship, ensuring its place in motorsports history.