When it comes to four-rotor Mazda engines, our thoughts first go to professional tire track makers like Mad Mike Whiddett and Rob Dahm, both of whom have successfully shoved four triangles into FD RX-7s. Well before either of them got in that business, Mazda developed four-rotor engines for racing, like the one in the 787B that triumphed at Le Mans in 1991. The 787B retired the same year due to the FIA changing engine regulations for the World Sportscar Championship, so Mazda brought its four-rotor R26B engine to the U.S. to contest IMSA’s GTP class in 1992. The car created around that engine was this, the RX-792P. The manufacturer intended to build three for the campaign, only two were completed, the third didn’t get far past the chassis stage. That third car has finally been built and completed to original spec and is now for sale, never raced. But it is, as the listing at Race Cars Direct notes, “ready to race.”
Legendary Mazda race car driver Jim Downing oversaw the build in his workshop. He was one of the early converts to RX-series competition cars, using one to win the IMSA GTU series in 1982. And after helping to create the IMSA Camel Lights class in 1985, he won the class championship its first three years in the Argo JM16B with and JM19 cars that were sometimes powered by the Mazda 13B two-rotor Wankel. Among many other accolades, he’s also the guy who co-developed the HANS device with his brother. Mazda awarded him the Spirit of Mazda award in 2019.
As for the RX-792P, it had a hard time during its sole year in competition. The excellent reliability that carried the underpowered 787B to victory didn’t make the jump across the Atlantic, leaving the underpowered 792-RXP beset by finishes many laps behind the leaders when it managed to finish at all, in addition to the occasional fire. When IMSA decided in late 1992 to eliminate the GTP category, Mazda canceled the RX-792P program.
Downing touches on the build in a video about his collection, and he’s put chassis number RX792P003 through shakedown laps himself at Road Atlanta. He’s asking $1.5 million. The four-rotor Wankel scream alone is worth half that much.