RET’s reporter at the centennial Le Mans 24 Hour race in June, Andrew Noble, witnessed the unveiling of a hydrogen-fuelled project car that is currently testing on European circuits. The base car is the Ligier JS2 R, the track-only mid engined road car-style coupe manufactured by Ligier Automotive. This has its own one-make race series and was designed as a homage to the original 1971 born Ligier JS2 road/ competition car, which in 1975 was a runner up at Le Mans using a Cosworth DFV V8.
The JS2 R is powered by a Ford Cyclone V6 twin turbo displacing 3.7 litres. Its hydrogen derivative, the JS2 RH2, has been developed in association with Bosch Engineering, which has been responsible for engine development. Strangely the base engine has not been revealed, other than the information that it is a production-derived 3.0 litre V6 twin turbo.
The JS2 RH2 is described by the two parties as “the product of the strategical and technical partnership launched between [us] in November 2022”. We were further informed: “Bosch Engineering oversaw the overall vehicle design including electrical/ electronic architecture and simulation. It played the key role in developing the concept for the engine and tank system, and a comprehensive multistage hydrogen safety system.
“Ligier Automotive was responsible for the global vehicle dynamic performance, the design of the monocoque, and the chassis adaptation of its existing Ligier JS2 R. [It] also optimised the mechanical components for use with hydrogen and led their overall integration into the new vehicle.”
That work included the substitution of the existing chassis structure by a new carbon monocoque that integrates three 52 litre, 700-bar type IV hydrogen cylinders from Hexagon Purus storing a total of 6.3 kg hydrogen.
Bosch Engineering here deploys its MG1 ECU. It adds: “the conversion [of the engine] for use with hydrogen involved in particular adapting the ignition and the entire injection system. Not only does the engine concept ensure very lean combustion, with especially low nitrogen oxide emissions up to partial load it also delivers a very high specific output. Another challenge while developing the engine was to achieve stable combustion without preignition at high loads and engine speeds of over 7,000 rpm.”
The current output is quoted as 420 kW (563 bhp) and 650 Nm torque with ongoing development of combustion characteristics expected to provide an increase in power.