No other car dominated the IMSA GTP series as thoroughly as the Eagle MkIII did during its two full seasons of racing. Dan Gurney’s All American Racers entered 27 races with the GT prototype, winning 21 – an impressive record achieved through driver skill, good teamwork at the track, and most importantly of all, some ingenious technological innovations that set new trends in GT car design. Chassis designer John Ward was one of the men tasked with creating the MkIII. For AUTOMOBILSPORT, he lays out the technology behind this iconic car.
To understand the development history of the Eagle MkIII, one has to know a little bit about IMSA GTP racing. The series started in 1981 with mostly Chevrolet-powered privateer entries, but in 1984 Porsche introduced its 962 chassis, which was the car to beat from 1985 to 1987. Over time, more manufacturers got involved. From 1988 to 1991 the Nissan factory-backed cars dominated over Porsche, Chevrolet, Jaguar, Mazda, and Toyota.
In late 1991 the Eagle MK III made its debut at Laguna Seca, qualifying second and dominating the race. However, it did not win, due to a pit stop infraction as I remember. The next race at Portland, the car scored its first victory with Juan Manual Fangio II, the nephew of the legendary Formula 1 world champion, at the wheel. It won again at the season finale at Del Mar. From then on, the MkIII was virtually unbeatable, winning 19 out of 26 races in 1992 and 1993, and the championship each year. 14 of those wins came in succession – actually, the car won all of the last 17 races it entered (it did not start at Road America in 1993).
The chassis and aerodynamic rules were loosely based on European FIA Group C prototype chassis rules. But whereas the Group C cars raced with fuel mileage restrictions, there was no such limit in the IMSA GTP. The engines were restricted with ‘sonic’ orifices, however, to limit engine air intake flow and hence power.
Dan Gurney and AAR had given me my start back in 1976, and my heart was always there no matter where I was. I had gone off to explore other opportunities after 1981, but in late 1989 I jumped at the chance to design a new GTP car when Dan offered. The moment I saw these cars run, I was hooked. They were governed by a pretty free set of rules, had a lot of power, and were technically very challenging – just what Dan, AAR, and designers like me wanted…
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