Old School GTP – AAR Toyota Eagle

(featured image credit: Motohide Miwa)

By Doug Schneider

Legendary American racers Dan Gurney and Carroll Shelby shared a dream of building an American race car that could compete with the best cars from Europe. Together, they formed All American Racers in 1962, based in Santa Ana, California. Through the ‘60s, ‘70s, and early ‘80s, the team successfully competed in USAC and CART with its Eagle cars, and in Formula One during the late ‘60s. The team entered IMSA competition in 1983, contracting with Toyota to run a Celica. The AAR-Toyota partnership had a successful run in the GTO and GTU classes from 1983 to 1988, winning the 1987 GTO Driver’s and Constructor’s Championship with Chris Cord behind the wheel.

The team moved up to the GTP class for the 1989 season, facing the daunting task of toppling the dominant Electramotive Nissan team. It entered two cars – a modified Toyota 88C, which had been competing in WSC Group C in 1988, and an AAR-designed Eagle HF-89 (also called the Eagle MkII; the “HF” designation came from the surnames of its designers, Ron Hopkins and Hiro Fujimori). Both cars were powered by the same turbocharged 2.1L inline-4 engine, which produced about 600 hp, similar to the engines that AAR had used in their GTO and GTU cars. AAR’s design priorities for the HF-89 were a chassis that was safe and robust yet stiff and light, and a simple, efficient design that allowed for adequate cooling of both engine and driver.

credit: Mark Windecker

credit: Mark Windecker

The 1989 season was marred with problems for the HF-89. It debuted at Miami, driven by Willy T. Ribbs and Juan Manuel Fangio II, but retired from the race due to a timing belt malfunction. Ribbs would bring the car its best finish, a fourth place, in the season’s last race at Del Mar. The 88C had better success that season, attaining seven top five finishes with Chris Cord, Drake Olsen, and Fangio sharing driving duties. For 1990, the team dropped the 88C and competed with two HF-89s. After a poor start to the season, Fangio drove the car to its first win in May at Topeka over the mighty Nissan GTP ZX-T. Fangio and the HF-89 would win two more races that season. A slightly modified version of the HF-89, the HF-90, was run in five races in the second half of the season, winning at San Antonio with Fangio driving.  By this time, it was apparent to AAR that there was little room for improvement in the HF-89. While the car was a success, it was a difficult car to tune and setup. Said Fangio, “When we were in the window, the car was good in every way, but if out of the window, the car was not right at all.” If the team wanted to beat the Nissans, it had to design a whole new car. It also lacked front downforce, and the imbalance created a strong understeer tendency.

Using lessons learned from the HF-89, work began on a new car in 1991 – the Eagle MkIII. John Ward was the Chief Designer, and Hiro Fujimori was Head Aerodynamicist, with Dan Gurney overseeing the entire project. The project was internally known as WFO-91, for Ward, Fujimori, and Others – or, unofficially, Wide F’n Open. The goal was a simple, uncluttered design with minimal drag and maximum efficiency. To improve front end downforce, Fujimori designed a separate nose diffuser, followed by a formula car-style underbody, a design inspired from the team’s experience with Indy cars. It was a revolutionary design, as other GTP and Group C cars at the time used a single set of underbody tunnels running from front to rear. Fujimori’s design would continue to be an inspiration for prototype race cars into the present day. The car’s design also allowed for a wide range of aerodynamic configurations, allowing for easier setup at a variety of tracks. A single nose air inlet was used to feed air to several cooling systems, which reduced surface turbulence and drag. The HF-89’s aluminum monocoque was traded for a carbon fiber-aluminum composite. Work was done on the diminutive engine, and Toyota Racing Development engineers were able to raise its power to over 800 hp with a new engine management system. Gurney later said that TRD blew up four dynamometers while working on the engine. Testing in the spring of 1991 made it clear that the car was far superior to the HF-89/90.

credit: Bill Wagenblatt

credit: Bill Wagenblatt

AAR ran the HF-90 for most of the 1991 season until the MkIII was ready. Fangio picked up one win at Watkins Glen before the new car debuted in July at Laguna Seca. Fangio led most of that race by a large margin, at one point by nearly a minute, but he finished seventh due to a pit stop penalty. One week later at Portland, Fangio drove the MkIII to its first victory. He would also win the season finale at Del Mar. Fangio described the car as “fantastic to drive; it had excellent balance.”  1992 began a period of historic dominance for the AAR Toyota Eagle MkIII – nine wins (seven for Fangio, two for P.J. Jones), including the final seven in a row. Rather than spend heavily to upgrade their cars to compete on the level of the MkIII, Jaguar and Nissan decided to pull the plug on their GTP efforts. With no serious competition in 1993, the AAR team won every race that season, and finished one-two in all but three races.

The AAR Toyota Eagle MkIII is considered by many to have been the best car in the greatest era of American sports car racing. It won 23 out of 27 races it entered. It was voted Car of the Decade by On Track Magazine. But it was a victim of its own success. Thin fields and a lack of competition in 1993 doomed the series, and the end of the GTP era was at hand. IMSA founder John Bishop’s vision of privateer teams competing evenly alongside factory programs was long gone as costs spiraled upward. An economic downturn in Japan led to a readjustment in spending priorities for manufacturers. A new direction was needed. Costs had to be cut down, and new rules would have to be straightforward. World Sports Cars became the new prototype category for 1994, with open cockpits, flat-bottom chassis, and production engines.  With the demise of the GTP class, AAR pulled out of prototype racing and returned to CART, leading Toyota’s effort in that series. The team ceased active racing after the 1999 CART season, but continues to build race cars. AAR constructed the Ben Bowlby-designed Deltawing.

About the author

Matt

Matt Kistler is the founder and editor of NASportsCar. Matt works full time for a Fortune 500 life Insurance company and runs Kistler Media on the side producing digital media of all kinds.

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