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  Article Image gallery (16) RX-7-1 Specifications  
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Built in:Raleigh, North Carolina
Produced in:1985
Designed by:Team Highball
Author:Wouter Melissen
Last updated:October 16, 2017
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Click here to download printer friendly versionMaking the most of the more lenient IMSA regulations, Amos Johnson of Highball Racing set about constructing a new RX-7 inspired GTU racer with full permission of Mazda. Although the work started late in 1984, the target for the car's first race was the 1985 season opening Daytona 24 Hours. Remarkably, the car was actually still being built at the track ahead of practice but by the end of the weekend, the all-new GTU car had clinched a debut class victory.

Although homologated as a GT car, Team Highball's new RX-7 was the first GTU car built around a bespoke spaceframe chassis. To still meet the homologation requirements, the chassis was clothed in a body that just about matched the silhouette of the first generation Mazda RX-7. Suspension was by double wishbones at the front and a live rear axle. As raced at Daytona, the RX-7 featured a mildly modified version of the RX-7 road car's 12A engine, mated to a five-speed gearbox.

For the car's Daytona debut, Johnson was joined by regular co-driver Jack Dunham and Japanese racing legend Yojiro Terada. Johnson continued to race the car throughout the 1985 IMSA Championship but after the debut victory, no more (class) wins were scored. Now joined by Dennis Shaw, Johnson and Dunham were back in top form at the next Daytona 24 Hours. Starting a lowly 51st, they placed eighth overall, which was enough for another class win in the gruelling race. Like in 1985, no further class wins were scored in 1986.

Ahead of the 1987 season, Team Highball substantially reworked the car to match the recently introduced second generation RX-7. In addition to the revised body panels, the car was also fitted with a new Type 13B engine. This was eventually upgraded with 13J rotors and a fuel injection system developed for a six-cylinder engine powering Cessna airplanes. In this guise, the very compact engine produced around 345 bhp.

The heavily revised Team Highball RX-7 continued the tradition and won the GTU class for a third consecutive time in 1987, this time with Johnson, Shaw and Bob Lazier behind the wheel. Johnson also won the GTU class at Riverside. During its fourth season, the car was driven to yet another Daytona class win and also to a class win at Sebring for the first time. For the success with his RX-7, Johnson was awarded with a works drive in 1990. The GTU car was leased out and scored its fifth class win at Daytona.

With five wins at Daytona, the Team Highball RX-7 is the single most successful chassis ever (the second best has 'just' three class wins). With a class win at Sebring also on its tally, the GTU RX-7 is also the most successful endurance racing chassis. With its many wins, the Team Highball car contributed considerably to the over 100 IMSA class wins scored by the RX-7.

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  Article Image gallery (16) RX-7-1 Specifications