Mazda 787B
The Mazda 787 and its derivative 787B are Group C sports prototype racing cars that were developed by Japanese automobile manufacturer Mazda for use in the World Sportscar Championship, All Japan Sports Prototype Championship, and the 24 Hours of Le Mans from 1990 to 1991. Designed to combine a mixture of the Fédération Internationale du Sport Automobile Group C regulations with the International Motor Sports Association GTP regulations, the 787s were the last Wankel rotary-powered racing cars to compete in the World and Japanese championships, using Mazda's R26B engine.
Although the 787 and 787B lacked the single lap pace of World Championship competitors such as Mercedes-Benz, Jaguar, and Porsche, as well as Japanese Championship competitors Nissan and Toyota, the 787s had reliability that allowed them to contend for their respective championships. The reliability of the cars eventually paid off in 1991 when a 787B driven by Johnny Herbert, Volker Weidler, and Bertrand Gachot went on to victory in the 1991 24 Hours of Le Mans. As of 2025, this remains the only victory by a car not using a reciprocating engine design. It was the first victory by a Japanese manufacturer, and the only such victory until Toyota won the 2018 24 Hours of Le Mans.
A total of two 787s were built in 1990, while three newer specification 787Bs were built in 1991.
Development
The initial design of the 787 was an evolution of the 767 and 767B designs that had been used by Mazda in 1988 and 1989. The 787 name was used instead of 777 to indicate a two-step improvement over the 767, and possibly over pronunciation difficulties of 777 in Japanese. Many mechanical elements of the 767 were carried over by Nigel Stroud when he designed the 787, but with some notable exceptions. Foremost was the replacement of the 767's 13J Wankel rotary engine. In its place, the brand new R26B was installed. The custom-built R26B featured a nearly identical layout and displacement, but included new design elements such as more granular variable intakes and three spark plugs per rotor instead of the 13J's two along with ceramic apex seals and variable length trumpets, among other modifications for increased efficiency. This allowed for a maximum power output of at a redline of 10000 RPM, which was reportedly limited to 700 hp at 9000 RPM during the 1991 race at Le Mans for longevity. The five-speed gearbox manufactured by Porsche, also mounted on the 767 and 787 was retained.Other modifications made to the 787's design included a relocation of the radiators. Initially placed beside the cockpit on the 767, a new single radiator was integrated into the nose of the 787. Air moved from the blunt nose of the car underneath the bodywork and through the radiator before exiting in front of the windshield. A Gurney flap was located at the radiator exit to increase front-end downforce. This new radiator location also meant a redesign of the doors of the car, where the old radiator design had been located. The intake in front of the door and exit behind were no longer necessary and were thus not included, giving the 787 a smoother bodywork design on top. To aid in rear engine and brake cooling, intakes were placed on the side bodywork, immediately above the exhaust cooling vents.
As before, Stroud's monocoque design was built from carbon and kevlar by Advanced Composite Technology in the United Kingdom. Carbon fiber body panels were affixed to the two initial chassis that were built in 1990.
787B
Following the 1990 season, Mazda continued development of the 787 chassis in order to make improvements on its pace and reliability. One major development was the intake system for the rotary engine. In the past, Mazda had developed variable-length telescopic intake runners to optimize engine power and torque for varying RPM levels. For 1991, the system became continuously variable, rather than previous versions that had steps for different engine ranges. This resulted in an increased torque of at 6,500 rpm. The 787B's onboard ECU controlled the action of the telescopic intake. Another main improvement was the change in suspension geometry which allowed for larger wheels to be fitted along with carbon ceramic brakes, a first for a Mazda racing car.The engineers at Mazdaspeed determined that fuel efficiency was crucial for achieving victory so they restricted the redline of the engine to 8,500 rpm thus reducing the power output to. Emphasis was put on high cornering speeds rather than attaining high top speeds at the straight sections of the track. Jacky Ickx was appointed as an advisor to guide the team in preparing the car.
Three new 787Bs were built for 1991, while the two existing 787s were also upgraded with the new intakes. For Le Mans, two 787Bs were entered along with a 787 in the C2 class which were subject to greater restrictions than the newly introduced C1 class in which the cars were fitted with 3.5-litre Formula One-inspired naturally aspirated engines. The third car was built primarily to replace the Le Mans winning car in competition but it retired in 1992 with no notable success.
Racing history
1990
The first 787 chassis made its competition debut in April 1990, at the second round of the All Japan Sports Prototype Championship season. For the Inter Challenge Fuji 1000 km, Mazdaspeed entered their 787 alongside an older 767B chassis, with Yoshimi Katayama, David Kennedy, and Pierre Dieudonné in the new car. After Fuji, the second 787 chassis was completed, and the team departed for Europe to prepare for Le Mans. Tests were performed at the Silverstone Circuit in Great Britain and Autódromo do Estoril in Portugal to prepare the car's setups and test its endurance. A total of were completed over the tests.Former Le Mans-winner Jacky Ickx was hired by Mazdaspeed in order to prepare the two 787s, as well as an older 767B, for the race. Driver Stefan Johansson joined Kennedy and Dieudonné in the first car, and Bertrand Gachot, Volker Weidler and Johnny Herbert were hired for the second entry. The all-Japanese line-up of Katayama, Yojiro Terada and Takashi Yorino remained in the 767B. In qualifying the new 787s set the 22nd and 23rd fastest lap times, ahead of the 767B's 34th fastest time.
The two 787s ran reliably for much of the race, lasting through the night until problems were encountered in the early hours of Sunday morning. While leading their GTP class, an oil leak on the No. 201 entry for Kennedy, Dieudonné, and Johansson forced the team to retire the car. Two hours later, the No. 202 787 was also retired after an electrical failure and fire. Heat from the engine was blamed for both failures. The 767B, the only car remaining in its class, survived until the end of the race and finished 20th.
After Le Mans, Mazdaspeed withdrew the remaining 767B from competition. Two 787s were entered for the rest of the JSPC season with the Japanese trio of drivers in one entry and Kennedy and Dieudonné remaining in the other. Returning to Fuji, the 787s earned fifth and tenth-place finishes in a 500 km event, although the fifth-place finisher was later disqualified due to a fuel cell that was too large. Tenth place was again earned at the 1000 km of Suzuka, although the all-Japanese entry retired after an engine failure. A similar result occurred at Sugo, except it was the Japanese squad that finished eleventh while the international squad had an engine failure.
For the last event of the season, the 1000 km of Fuji, Mazdaspeed entered the two 787s and a 767B, brought out of retirement. It finished sixth: one 787 was seventh and the other retired following a transmission failure. Mazdaspeed's Yoshimi Katayama earned 25th in the drivers' championship, and Mazda was fourth in the constructors' championship.
1991
For the 1991 season, Mazda expanded their efforts with the 787. Two cars were assigned to the JSPC series, while a third car ran the full Sportscar World Championship season for the first time, with drivers David Kennedy, Maurizio Sandro Sala, and Pierre Dieudonné assigned to the team. The French Oreca team were put in charge of the world championship campaign. Oreca and team consultant Jacky Ickx were able to persuade FISA that the 787s should be allowed to run with less weight than their competitors, leading to FISA allowing the team to run the cars at rather than the standard required for the C2 class.Unlike the JSPC series, FISA had begun to integrate regulations for a new engine formula in the world championship, which required all teams to use 3,500 cc engines for 1991. Cars that met these regulations in 1991 became the top C1 class, while cars with other engines, including the 787, were reclassified as C2. The C2 class cars also retained the fuel consumption formula that group C had been founded on, while C1 cars no longer required it. This meant that Mazda now had to fight for class wins within their new class. In the JSPC, however, Mazda's 787s remained in the GTP class, as the sole competitors in the category.
The year started in Japan, with Mazdaspeed entering two older 787s while the new 787Bs were being finalised. Both cars suffered problems and were uncompetitive. Attention then turned to the Suzuka Circuit, where the début race of the world championship season was being run. The first new 787B chassis arrived alongside an older 787. The newer car, with Sandro Sala and Kennedy, out-qualified the older chassis driven by the all Japanese squad by only an eighth of a second, but the 787B was able to outlast several other competitors and finish in sixth overall, fourth in the C2 class, and earning Mazda points in the championship.
The 787B was retained in Japan while the European squad turned to Monza with an older 787. Yojiro Terada and Takashi Yorino earned the new 787B another sixth-place finish at the 1000 km of Fuji, while the European team finished seventh at Monza on the same day. A poor race at Silverstone added no points to Mazda's world championship total before the team concentrated on Le Mans.
Following the team's Le Mans victory, Mazdaspeed returned to Fuji once more with a 787B, and improved their season results with a fourth-place finish followed by another sixth at Suzuka. A third 787B was completed by October, and the two cars finished in third and fourth places at the second 1000 km of Fuji. To end the season, the team finished in sixth at Sportsland SUGO, earning Mazda fourth in the constructors' championship, and Takashi Yorino fourteenth in the drivers' championship.
The European squad meanwhile continued to use the older 787, finishing in fifth at the Nürburgring and seventh at Magny-Cours. The championship then flew to Mexico City where Mazda finished ninth, before the season ended back in Japan. The two 787Bs of the Japanese squad replaced the older 787, and the two cars finished in ninth and tenth places. Mazdaspeed finished fifth in the teams' championship, and Maurizio Sandro Sala earned fifteenth place in the drivers' championship.