Audi 90 quattro IMSA GTO
When Trans-Am banned 4WD just after the Audi 200 won the 1988 season, Audi switched to the IMSA series and set about creating an all-new tubular steel spaceframe, clothed in a body that resembled the 90 quattro but only if you’d consumed your body weight in strong liquor. We like the fact that it efectively shoehorned the gizzards of the highly successful world rally car – and Walter Röhrl’s Pikes Peak ’87 record-setting monster – into a silhouette track car. Remember, then, Audi was still something of a niche concern, for whom the endurance racing and Le Mansslaying dream was still a decade or more away.
The 20v, 5cyl 2.2-litre had a massive KKK turbo bolted onto it, and now made about 720bhp. Most of the engine was sited ahead of the front axle. The exhaust exited, in hugely unsubtle fashion, through what would have been the passenger door on the road car; the only thing carried over from the realworld 90 was its roof. Various carbon composites were used in the body, and a lot of wind tunnel efort was expended on the air dam and large rear wing. The suspension used double wishbones and coil springs, with ventilated discs all round.
Audi of America ran the IMSA campaign itself. With the Trans-Am champ Hurley Haywood retained, alongside the mighty Hans-Joachim Stuck, the team won seven of the series’ 13 races, but was beaten to the punch by the Mercury Cougars being run by Roush Racing.
Electing to miss both that year’s Daytona and Sebring races, as the car was still being tweaked, the mad Audi debuted in Miami, where gearbox problems distracted from its pace, a glitch swiftly overcome. Stuck and Haywood scored a one-two at Summit Point; in May 1989, Stuck won again in Mid-Ohio, then again in Topeka, at Sears Point, at Watkins Glen, Lime Rock, and at Laguna Seca. He fnished third overall, while Audi was runner-up in the constructors’ championship. If they’d raced at Daytona and Sebring, they’d have won both.
Despite this strong showing, Audi’s German bosses preferred to focus its motorsport eforts on the domestic DTM series, pulling the plug on the US exploits after just one glorious season. This brevity is another reason the 90 quattro lingers long in the memory. “When we came to the States with this car,” Stuck remembered 20-odd years later, “nobody can believe what we can achieve… small engine, fve cylinder, it’s a German saloon car! We could use a later braking point, and practically any line we wanted. When I crossed the fnish line, I started yodelling!”