Toyota is going for glory in the 2022 ENEOS Super Taikyu Series with not one, but three cars powered by three different fuels. Well, no harm in hedging your bets, is there? If you haven't heard of the Super Taikyu Series, it's Japan's touring car endurance racing with cars ranging from FIA GT3 spec to those with effective displacements under 1,500cc. Races are held at circuits across Japan, including the Fuji International Speedway and Suzuka, where the season kicked off last weekend.
In the hydrogen corner is the Toyota Corolla H2 Concept. This actually made its debut in last year's series, running at four rounds between May and November. It runs a hydrogen combustion engine (note, it's not a fuel cell) and over that initial development period the engine's power was increased by 24 per cent and torque by 33 per cent. Toyota claims the power increases raise the hydrogen motor's outputs to a level that is comparable with petrol-powered engines. The team also got a handle on 'abnormal combustion,' which is the loss of performance and engine damage that results from cylinder knock or surface ignition.
This being endurance racing, refuelling is a part of the challenge and another area of development. Last year the team improved the Corolla H2's design so that it can be refuelled from both sides. This year it is taking on the challenge of "high flow filling" by upping the pressure that the fuel is under during refilling. Filling a hydrogen tank quickly causes a rapid increase in its internal temperature, which, obviously, is not what you want with a highly combustible fuel.
So Toyota has modified the filling port and the fuel pipes to handle larger flow rates without reaching dangerously high temperatures. This has already reduced the refuelling time from just under two minutes to one-and-a-half minutes. Clearly the fewer times you need to stop is another way to improve the car's potential. The Corolla H2's range has already been improved by 20 per cent since the end of the 2021 season, and further gains are targeted this year.
It's not just the racing car that's being worked on; how the hydrogen is transported is also being developed. Toyota has moved away from carrying it to the circuit in metal tanks and is now using lightweight resin liners. Their design is based on the high-pressure fuel tanks for the Toyota Mirai fuel cell car. The higher pressure the fuel is held under increases the quality of hydrogen on board by around four times. It's also worth noting that for last weekend's five-hour race at Suzuka, the Corolla H2 Concept used hydrogen derived from solar power.
Next on the entry list is the GT86 CNF (Carbon Neutral Fuel) Concept. Instead of a flat-four, this uses a 1.4-litre inline motor based on the GR Yaris's engine (and also the engine used in the Corolla H2). The fuel used emits similar amounts of CO2 to a fossil-fuelled car, but because the fuel is made entirely from CO2 already present in the atmosphere, it is considered carbon neutral.
It's a similar philosophy to the Prodrive Hunter T1+ cars at this year's Dakar Rally, which used a 90 per cent concentration of GENII biofuel. Toyota says it "will be able to use motorsport as means of training, discovering issues, making improvements and exploring the possibilities for future practical applications of the fuel, with a view to expanding internal combustion engine fuel options." Hurrah to that. And the world's largest car manufacturer will even be sharing the information it gleans from its racing endeavours with series' rivals Mazda and Subaru, which are also fielding bio-concept cars.
And finally, there's a petrol-powered GT86. The this is running racing-grade petrol, and it's the nearest of the trio to a production-spec car. As with the GT86 CNF Concept, the GT86 will be used to evaluate developments for the forthcoming GT86 that we drove in prototype form late last year.
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