Mazda 787B

The 787 was an evolution of the 767 and 767B designs used by Mazda in 1988 and 1989. The 787 name was chosen to indicate a two-step improvement over the 767, and possibly to avoid pronunciation difficulties with "777" in Japanese. Designer Nigel Stroud carried over many mechanical elements of the 767 while making significant changes. The 767's 13J Wankel rotary engine was replaced by the brand-new R26B. The R26B featured a nearly identical layout and displacement to the 13J but introduced more granular variable intakes, three spark plugs per rotor (versus the 13J's two), ceramic apex seals, and variable-length trumpets, allowing a maximum power output of 900 hp (670 kW) at a redline of 10,000 rpm. The five-speed gearbox manufactured by Porsche, also used on the 767 and 787, was retained.

The radiator was relocated from beside the cockpit — as on the 767 — to a single unit integrated into the nose. Air entered through the blunt nose, passed under the bodywork and through the radiator, and exited in front of the windshield; a Gurney flap at the exit increased front-end downforce. This redesign also resulted in smoother door bodywork, as the old radiator intake and exit on the doors were no longer needed. Side bodywork intakes above the exhaust vents aided rear engine and brake cooling. Stroud's monocoque was built from carbon and Kevlar by Advanced Composite Technology in the United Kingdom, with carbon fibre body panels on both 1990 chassis.

For 1991, Mazda developed the 787B from the existing 787 chassis. The intake system became continuously variable rather than stepped, optimising power and torque across the rev range and yielding 608 N·m (448 lb·ft) at 6,500 rpm, controlled by the onboard ECU. Suspension geometry was revised to accommodate larger wheels, and carbon ceramic brakes were fitted — a first for a Mazda racing car. To prioritise fuel efficiency and cornering speed over outright top speed, the redline was restricted to 8,500 rpm, reducing power to 650 hp (485 kW). Jacky Ickx was appointed as an advisor to guide the team's preparation.

Three new 787B chassis were built for 1991; the two existing 787s were also upgraded with the new intake system.

The first 787 chassis made its competition debut in April 1990 at the Inter Challenge Fuji 1000 km in the All Japan Sports Prototype Championship, entered alongside an older 767B. After Fuji, the second 787 chassis was completed and the team travelled to Europe, conducting tests at Silverstone and the Autódromo do Estoril covering 2,900 miles (4,700 km). Former Le Mans winner Jacky Ickx was hired to help prepare the cars for the race.

For the 1990 24 Hours of Le Mans, Mazda entered two 787s and a 767B. The No. 201 car for David Kennedy, Pierre Dieudonné, and Stefan Johansson retired with an oil leak; the No. 202 787 of Weidler, Herbert, and Gachot retired two hours later due to an electrical failure and fire — heat from the engine was blamed for both failures. The 767B finished 20th. After Le Mans, the 787s continued in the JSPC season, earning mixed results; Yoshimi Katayama finished 25th in the drivers' championship and Mazda placed fourth in the constructors' standings.

For 1991, Mazda assigned two cars to the JSPC and entered one car for a full World Sportscar Championship season — the European campaign managed by the French Oreca team with consultant Jacky Ickx. FISA allowed the 787s to run at 830 kg rather than the standard 1,000 kg for the C2 class, to which the rotary-engined cars were reclassified after FISA introduced a new 3,500 cc engine formula as the top C1 category.

At the 59th 24 Hours of Le Mans — the fourth round of the World Sportscar Championship — Mazda entered three cars and a spare. The No. 55 787B (chassis 002), driven by Weidler, Herbert, and Gachot, wore a distinctive bright orange and green livery in honour of sponsor Renown, a Japanese clothing manufacturer that had backed the team since 1988. The No. 18 787B (chassis 001) carried Maurizio Sandro Sala, Johansson, and Kennedy, in a standard blue-on-white livery. The No. 56 787 was driven by Dieudonné, Takashi Yorino, and Yojiro Terada.

The three Mazdas started 19th, 23rd, and 30th on the grid — behind the new 3.5-litre C1 cars, which were awarded the front grid positions. On the eve of the race, team manager Ohashi instructed the No. 55 crew to drive as if in a sprint race, a decision based on the car's demonstrated reliability and exceptional fuel economy. In the early stages, No. 55 moved to third; the No. 18 ran behind it, with a lower gear ratio setup that reduced fuel consumption at the cost of 20 km/h (12 mph) of top speed. No. 55 advanced to second when the Mercedes-Benz C11 of Michael Schumacher, Fritz Kreutzpointner, and Karl Wendlinger spun off and later pitted with a gearbox problem. At the 22nd hour, No. 55 took the lead after the other C11 of Alain Ferté pitted with mechanical problems. At the final pit stop, Herbert asked to stay in the car and drove it across the finish line first, completing 362 laps and covering 4,932.2 km — both new records for the recently modified circuit. No. 18 finished sixth and No. 56 eighth. Herbert was so dehydrated he needed assistance leaving the car and could not attend the podium; Weidler and Gachot accepted the trophy. The winning car ran without significant problems apart from a blown headlamp bulb and a precautionary rear wheel bearing change.

A number of rivals were concerned about the reliability of the new 3.5-litre formula: Jaguar entered their older XJR12 alongside a sole XJR14, and Sauber chose to run the older C11 rather than the new C291.

After Le Mans, Mazda returned to Japan with the 787B and improved their JSPC results, recording a fourth, two sixths, and a third-and-fourth double finish. The European squad continued with an older 787, finishing fifth at the Nürburgring and seventh at Magny-Cours. Mazda finished fourth in the JSPC constructors' championship and fifth in the world teams' championship.

At the end of 1991, the Group C series was replaced by a 3.5-litre World Sports Championship; Wankel rotary engines were outlawed by the Fédération Internationale de l'Automobile, and 3.5-litre engines similar to Formula One became the mandatory formula for 1992. Mazda subsequently entered the MXR-01 — based on the Jaguar XJR-14 and powered by a Judd unit — in 1992 with limited success.

Despite the historic Le Mans win, Mazda did not heavily exploit the victory in marketing campaigns. In the United Kingdom, Mazda introduced a special edition of the MX-5 in the racing colours; only 24 were produced. The winning 787B (chassis 002) was retired from competition after Le Mans; the other two chassis continued racing into late 1991. Chassis 002 was displayed at the Otaru City Museum for 20 years before being returned to Mazda headquarters in November 2015; Mazda normally keeps it at the Mazda Museum in Hiroshima. Mazda produced two replicas, donating one to the Le Mans Museum.

Herbert went on to a successful Formula One career, recording three wins before leaving the championship in 2000. Gachot drove for Jordan Grand Prix in 1991 before receiving an eighteen-month prison sentence for a CS gas attack on a London taxi driver; his place at the Belgian Grand Prix was taken by Michael Schumacher in his Formula One debut. Gachot was released after two months and achieved minor successes before retiring. Weidler competed in the Japanese Formula 3000 championship until tinnitus forced him to retire; he handed his seat to Heinz-Harald Frentzen. Dieudonné later retired from driving and became sporting director at Oreca, guiding the Dodge Viper to class wins at Le Mans and an overall win at the 24 Hours of Daytona in 2000. Terada, a Le Mans veteran since 1974, continued to race there without factory backing through his Autoexe tuning business.

The 787B is considered by Mazda and Wankel enthusiasts as one of the most iconic racing cars from Japan. It has appeared in the Gran Turismo series, the Forza Motorsport series, and Assetto Corsa. The 2008 Mazda Furai concept bore the number 55 of the winning 787B. On 24 December 2014, Mazda unveiled the LM55 Vision Gran Turismo concept as downloadable content for Gran Turismo 6, as a homage to the 1991 victory. After a restoration, the winning No. 55 787B was demonstrated at the 2011 24 Hours of Le Mans pre-race, driven by Herbert around the Circuit de la Sarthe. The R26B engine continued to appear in subsequent Mazda racing programmes through to 2005.

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