The history of the prototype in question goes back to the 1980s, when Mazda designed the first prototype 717C in 1983. In the years that followed, there were various evolutions that competed without any success. It was only in 1990 that the first Mazda 787 prototypes were built, which basically differed from the previous 767 by being equipped with a new engine development.
The Mazda 787 developed for 1990 were finally starting to position themselves as potential candidates for good results. The design of the new prototype was entrusted to the Englishman Nigel Stroud, who worked at the British company Advanced Composite Technology.
Nigel Stroud designed a new monocoque chassis with carbon compounds. The body was built in carbon fiber, which was already beginning to become a standard for this type of racing car.
The 787 redesign included a reduction in troches to improve aerodynamic efficiency and the adoption of larger diameter brake discs, now 360mm.
But the big change of the 787 prototype was in its engine. The new Wankel rotary engine (called 26B) was lighter, more compact and efficient in terms of fuel economy. It also adopted a Porsche 5-speed gearbox.
The new engine also had a major complementary technological breakthrough: the variable air intake system. This computer-driven device could modify the position of periscope air intakes for the engine. These shots could be raised or lowered, with a total travel of 15 cm. Thus, the air intakes descended at high speeds to reduce aerodynamic drag, while at low speeds they were raised to obtain more air at higher pressure to feed the engine rotors.
The Mazda 26B engine also had two spark plugs per rotor, making combustion more efficient and reducing consumption. Engineers emphasized maintaining a low rpm speed to gain reliability in long term races like Le Mans, with the limit of the 9,000 rpm impeller.
After conducting more than 4,500 km in rehearsals, Mazda decided to present three cars at Le Mans in 1990: two units of the new 787 and a relegated 767. During the race both Mazda 787 began blunt. But after 11 hours the best Mazda had to quit because of engine oil loss problems.
Two hours later, the second Mazda 787 suffered electrical problems and also left the competition. Ironically, the only Mazda to finish the test was the old 767 driven by three Japanese riders Yorino, Katayama and Terada, arriving in position 20.
In 1991 Mazda returned to Le Mans with an improved prototype, now known as Mazda 787B. Mazda participated in all races of the 1991 calendar, debuting in Suzuka with a 6th place. But the main objective was Le Mans.
Due to regulatory changes, in 1992 all traditional engines should conform to the same specifications as Formula 1. This meant that all brands had to work twice to develop new engines and adapt their chassis during 1991. Meanwhile, Mazda simply had to perfect the chassis-engine assembly, not altered by regulatory change. The Mazdaspeed Co. Ltd had absolute official backing.
However, other changes should be assimilated. For safety reasons, the Hunaudières straight of the Le Mans circuit would be divided into three, interrupted by two chicanas. This would mean less speed development and greater demand for brakes and tires. It was then that Mazda first used carbon brake discs.
The start of the competition was dominated by the Sauber Mercedes Benz C11. The Mazda made a spectacular comeback. During the night they were placed in second position after a dismiss of one of the Mercedes Benz C11. The German brand saw technical problems affecting their cars, while the reliable Mazda 787B kept moving forward.
After 22 hours of competition, the Mazda 787B #55 driven by Johnny Herbert, Volker Weidler and Bertrand Gachot was at the forefront of the competition. Mazda finally earned a historic victory driven by reliability, with the three Jaguar XJR-12 from the Silk Cut team as escorts.
The Mazda 787B #55 toured 4,932.2 km and completed a total of 362 laps. The other Mazda also played a good part. The second 787B was 6th with 355 laps, while the 787 took 8th place with 346 laps.
Subsequently, Le Mans winning Mazda was removed from the tracks to become part of the Mazda Museum in Hiroshima, Japan. The other two cars continued to compete in 1991 to finish fifth place in the FIA Championship.
At the end of the 1991 season the FIA announced that it would ban the use of rotary Wankel engines, allowing only engines with the same specifications as those of the F1. So Mazda was the only winner of Le Mans with a Wankel rotary engine, being also the last team to win there with Dunlop tires.
Interestingly, Mazda did not take advantage of this historic triumph as presumably to spread the success of its rotary engine development. Although they did see a small increase in sales of their small Wankel motorized street sports cars.
© Adrián Blanco 2008 - Prohibited the total or partial reproduction of text and/or images without explicit written consent of the author. —
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