When Johnny Herbert crossed the finish line at Le Mans on June 23, 1991, he was driving one of the best race engines of all time — an engine that had essentially already been banned. The Mazda 787B's four-rotor R26B was the last rotary-powered car to race at Le Mans, and the team knew beforehand that the 1992 regulations would make the engine ineligible. By the time the 1992 season approached, the Fédération Internationale du Sport Automobile (FISA) had made clear that rotary engines would no longer be permitted at Le Mans. Mazda's 787B was grandfathered into the 1991 race under existing regulations before the ban took formal effect the following year. Mazdaspeed had been campaigning rotary-powered cars at Le Mans since the 1970s, with the factory effort beginning in earnest in 1983.