The Mazda 787/787B were prototype Group C racing cars built for the 24 Hours of Le Mans and World Sportscar Championship, replacing the 767B. It used a 4-rotor R26B Wankel engine which produced over 700 hp (522 kW). Debuting in the 1990 24 Hours of Le Mans, and later in the All Japan Sports Prototype Championship, the initial 787 was plagued with problems. At Le Mans neither 787 were able to finish due to electronics and oil failures, although an older 767B was able to finish. For 1991, Mazda upgraded the car to the 787B, and for the first time entered into the full 1991 World Sportscar Championship season. At Le Mans Mazda was able to score a historic victory for not only the first and only victory for a Japanese manufacturer, but also the first and only overall victory for a car powered by a Wankel rotary engine. This car would be the culmination of Mazda's efforts with the rotary engine since the 1970s.