The Story of Mazda's Success in the IMSA GT Championship
In 1978 Mazda had decided to put in a factory effort in the popular IMSA GT Championship, a North American racing series which was production based and at the time not too high budget. For the first year they entered the RX-3, which was a mid pack car, but it allowed Mazda to collect data, data which could be used in the development of the car for the following year: the RX-7.
In 1979 Mazda came with their new RX-7 GTU race car. GTU stood for “Grand Touring Under 2.5L”. Mazda hired some guys from a company called Racing Beat to build them an engine, a naturally aspirated 2 rotor that developed over 250hp at 9500rpm. Mazda showed up to the 24 Hours of Daytona and not only qualified their two cars first and second in class, they then won their class and even got 5th and 6th overall. Having proven soundly both the reliability and the speed of the RX-7, Mazda quickly became a force throughout the championship, with their RX-7s commonly taking podium spots in their class. They lost out in the championship but would be back stronger the next year.
For 1980 Mazda returned with the RX-7s again, again entering two cars for the season and not missing the podium in any race all season. They clinched the constructor’s championship with three races remaining, proving that the rotary was a force to be reckoned with in the racing world. The dominance of the rotary became a trend in the championship.
After 1980 Mazda reduced factory backing and didn’t run a factory team, although their drivers easily found homes on many of the new teams that were building and running their own RX-7s. Although they were run by different teams and driven by different drivers, the RX-7 won the GTU driver’s championship for 7 years straight from 1980 to 1987, only challenged briefly by Toyota’s factory Celica team.
Mazda won the GTU championship one more time in 1990 with a fully factory backed MX-6. The car was able to run with RWD and a three rotor 20B due to a rule change pleaded by Toyota in earlier years. Toyota wanted to run the Celica in the series, but due to its small engine and FWD drivetrain, it would have been uncompetitive. After begging the organizers, they were permitted to run it with rule changes allowing cars to be run with any engines and drivetrains that still met regulations. The car failed to take the championship in 1989 but beat a privately run RX-7 to the championship in 1990 before Mazda switched its factory focus from GTU to GTO.
Racing Beat was more ambitious in the 1983 season, fielding a GTO car despite the engine still being only 1.3L compared to the rest of the cars in the class that were running engines over 2.5L. Despite this challenge they won the class in the 24 Hours of Daytona the first time out, proving that the small engined RX-7 could keep up and beat the big boys.
1984 brought the RX-7 its first GTO championship at the hands of Roger Mandeville, and despite the car being down on power it was able to secure solid points and fight for wins. The car was updated for 1985 but was unable to be as competitive with new entrants that were faster. Although Roger built and ran several iterations of the car over time, he found little success after his first championship and moved back to running the RX-7 in GTU.
For 1990 Mazda ran a factory backed GTO team alongside its GTU MX-6 team, fielding both the 3 Rotor MX-6 and the 4 Rotor RX-7, although the MX-6 saw more success that year than the RX-7. For the first year the flame spitting GTO car was only able to take 3rd in the championship, although the following year in 1991 it brought Mazda their final class crown in the IMSA GT Championship. This championship came in the wake of Mazda’s victory at Le Mans the same year, making 1991 one of Mazda’s most successful years ever in racing.
Mazda had their last hurrah in IMSA in 1992 when they campaigned the 4 Rotor powered RX-792P in the GTP class, hoping that the rotary’s success in the GTU and GTO classes would give it an edge there as well. Sadly the car was not very successful, with Mazda consistently a mid pack finisher in class, ending their days in IMSA with a car that surely sounded and looked amazing, but was unable to translate that into points.
After providing continuous factory support in the IMSA GT Championship for 14 years from 1978 to 1992, Mazda had amassed 10 championships, 8 in GTU and 2 in GTO, becoming the most successful manufacturer in the championship, which folded in 1994. Today Mazda runs a prototype team in the modern equivalent of the championship, the IMSA Weathertech Sportscar Championship, and are looking to bring back the success they found in the past.