Welcome to the IMSA History unofficial website

This site is aimed at bringing you memories from the glory days of sportscar racing in the US.



Constructor Toyo Kogyo Co.
Chassis Type: unibody Front and Rear Suspension: coilover.
Body Fiberglass front end, rear quarters, and hood.
Suspension Front wishbones, coil springs over dampers. Rear : rocker arms, coil springs over dampers
Gearbox 5 speed Manual.
Wheelbase : 2421mm
Front track 1420mm
Rear track 1400mm
Engine Type: hand built peripheral port 12A Mazda Induction: hand constructed intake with a Weber carb built by AEM in CA. Clutch: Mazda Comp clutch

At the time Mazda first showed up at Daytona in 1979, no one took care of this new team that came from Japan. They had come the previous year with RX3 cars and had applied what they had learned on the track. The two cars were destined to be driven by Japanese and American drivers. After qualifying first and second in class, they steadily dominated the race, to finish in fifth and sixth position overall. Yoshimi Katayama-Yojiro Terada-Takashi Yorino winning the GTU category and Walt Bohren-Jim Downing-Roger Mandeville second. It was not the first time Mazda entered an RX7 in an IMSA event as Al Cosentino was the first to enter such a car. Following their domination, IMSA decided to add an extra 458lbs to the cars. After a while, and following the drivers concerns about the extra weight, they reduced it to zero. The factory cars had been sold to Roger Mandeville and Jim Downing. At the end of the 1979 season, Don Devendorf won the title for Datsun, but Bob Bergstrom took second place in a Mazda. Mazda began racing RX-7s in the IMSA GTU series in 1979. That first year, RX-7s placed first and second at the 24 Hours of Daytona, and claimed the GTU series championship. The car continued winning, claiming the GTU championship seven years in a row. The RX-7 took the GTO championship ten years in a row from 1982. The RX-7 has won more IMSA races than any other car model.

 Chassis list