Audi 90 Quattro

The IMSA Audi 90 GTO was one of the wildest, most technologically advanced four-door race cars to ever hit the tracks. It was basically a 700bhp AWD Group B rally car engine-drive train package, mated to a space frame chassis, and draped with a carbon fiber silhouette body. The genesis of the Audi 90 GTO began with Audi's introduction of the now famous quattro system into the WRC in 1981. It seems a bit obvious by today's standards, but at the time, no one had successfully implemented an AWD system in rallying. The first Audi quattro rally car was very heavy and cumbersome compared to it's RWD competitors, but its traction advantage was such that by 1982 Audi were World Rally manufacturer champions. At this particular time, Audi's reputation in the US was suffering due to a spate of faulty brake/acceleration claims against the company.... so they turned to motorsports to rebuild their brand image in the US. So Audi dropped the rally engine and drive train into an Audi 200 unibody, built up a race car and entered the 1988 American Trans Am Series. Hurley Haywood won the title. A year later the company switched to the IMSA GTO series, with its less strict rules. Eager for a new challenge, Audi decided to build a car for the less restrictive and more professional IMSA Camel GT Championship. Only the silhouette of the Audi 90 quattro was retained: under the GTO's carbon-fibre skin was a pure racing car. The five-cylinder engine, in its final development stage, produced 529 kW (720 bhp), and the car's four driven wheels had 14-inch wide rims. A tubular chassis was used instead of the Trans Am car. The engine was derived from the 200 Quattro but its use was allowed by IMSA. An eight inch rear wing or a wider double wing was used for the faster tracks. A 150kg ballast was used for the entire season. The car also sported the transmission used by the Audi Quattro Sport S1. The IMSA Championshp was at the peak of its success in the late 80s and boasted separate Prototype and GT races at most of their events. Competition came from the factory Roush Racing Mercury Cougars and the Nissan 300Zs of Cunningham Racing. The Audi was much easier on its tires than its competitors, who struggled with tire wear over the course of a full stint. The ever reliable and developed quattro system was installed in a purpose built spaceframe clothed in a full carbon fiber shell. In spite of winning seven of the thirteen races, Audi lost the championship to Roush Racing that year. It probably didn't help that they sat out the two enduro races at the start of 1989: Daytona and Sebring. With seven wins in 13 races, Hans Joachim Stuck took third place in the championship and the team came second in the manufacturers' rankings.

The Audi 90 Quattro did well but lost the championship to the Mercury Cougars.