Could Mazda Return to Le Mans with a Hydrogen Rotary Hybrid

P1J04888sThe 2016 24 Hours of Le Mans will actually mark two very important anniversaries in the history of the world’s most famous endurance race. It will be the 50th anniversary of the first of four consecutive victories by the legendary Ford GT. It also marks the 25th anniversary of Mazda’s only victory with the rotary-powered 787B. Just after Ford announced it’s return to France next year, Mazda’s Nubohiro Yamamoto told Top Gear magazine that he would like to see the Japanese brand return to the endurance race.

Back in 1991, Yamamoto was the race engineer on the Mazda prototype that achieved the only Le Mans victory by a Wankel rotary. Today he is the project manager on the all-new MX-5 Miata. In an ideal world, Mazda would build an LMP1-class machine to challenge Porsche, Audi and Toyota for overall victory. Unfortunately, such a program would like cost $1 billion or more over the several years required to get cars developed and up to speed and that’s unlikely to happen for Mazda. That cost is precisely why Ford has opted to take on the GTE class with the new GT, but Mazda has no suitable car for that class right now.


However, I have what I believe to be a better suggestion that is more in keeping with where Mazda has some unique expertise. The Le Mans organizers have special program in the rule book for experimental racers called Garage 56 (in deference to the 55 official starting slots available). The most famous Garage 56 entrant so far was the 2012 Deltawing that was running strongly among the LMP2 class until getting unceremoniously punted off the course by one of the Toyotas.

While the P1 class gives manufacturers a lot of latitude in powertrain choice, only limiting the total energy consumption, the limitation to either gasoline or diesel might not be the best choice for Mazda. Garage 56 would enable Mazda to revive a development program that ran through much of the early 2000s, the hydrogen-fueled rotary. In the search for a zero-emissions powertrain, Mazda took advantage of its knowledge of the unique Wankel rotary.


While BMW built a test fleet of 7 Series V12 sedans that ran on hydrogen, the Wankel design is more inherently suited to hydrogen. Compared to gasoline or diesel, hydrogen is easier to ignite and burns much faster. In a piston engine, the valves and spark plugs that protrude into the combustion chamber, inherently get hotter than the surrounding cylinder walls and produce isolated regions of heat. When running a piston engine on hydrogen, they have a tendency to backfire as a result of spontaneous combustion.

The Wankel has no valves with intake air and exhaust gases entering and leaving via side ports in the chamber that are exposed as the rotor sweeps past. Mazda’s design utilized direct injection to spray hydrogen into the chamber after the ports were closed and quickly igniting the fuel. The result was high power density, and only water vapor as emissions. Now imagine pairing that with an electromechanical hybrid system like the type used by Audi in the R18 e-tron, a rotary engine with a rotary energy storage system! Or perhaps since Mazda and Toyota now have some joint development programs for production vehicles a supercapacitor system like that used in the Toyota TS040 LMP1 machine.

Either way, Mazda could harness some technology unique to its brand without necessarily directly challenging the brands that have been dominating Le Mans in recent years. If the car does well, Mazda could use it as an opportunity to introduce the technology to production applications. If not, they still get credit for trying something new.

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