BMW has argued the case for hydrogen power by setting nine new speed records in a prototype hydrogen version of the V12-engined 760i at Miramas in France.

BMW has argued the case for hydrogen power by setting nine new speed records in a prototype hydrogen version of the V12-engined 760i at Miramas in France.
The H2R Record Car was developed by BMW Forschung und Technik GmbH and can reportedly accelerate from standstill to 100 km/h in six seconds and reach a top speed of just under 300 km/h. In the hands of Alfred Hilger, Jorg Weidinger and Gunther Weber, from the BMW works team, the H2R set records for the fastest flying-start kilometre and mile, fastest standing-start one-eighth mile, quarter-mile, half-kilometre and mile, standing-start 10 miles, kilometre and 10 kilometres.
The Munich-based company says the event "clearly demonstrated the supremacy of BMW in developing the hydrogen engine to production standard", adding that it "would be launching a dual-mode version of the current 7 Series during the production cycle of the present model, thus introducing the first car of its kind able to run on both hydrogen and petrol."
BMW’s six-litre 12 cylinder engine was adapted to run on hydrogen fuel through the adjustment of engine management as well as the fuel/air mixture formation components. Significant differences in terms of the engine's structural components are the hydrogen injection valve and the choice of materials for the combustion chambers: Contrary to the production engine with fuel injected directly into the combustion chambers themselves, the injection valves in the hydrogen engine are integrated in the intake manifolds.
For the specific speed record requirements to be fulfilled in this case, the hydrogen combustion engine was built for single-mode operation running exclusively on hydrogen. That allowed the engineers to tune the engine specifically for hydrogen requirements, for example by using special valve seat rings made of an appropriate material.
A significant advantage of the higher combustion pressure of the hydrogen/air mixture, BMW says, is that the generation of more power from the same amount of energy means a higher degree of efficiency.

As desirable as the high standard of ignitability of hydrogen within the engine may be, it naturally requires a great deal of attention outside of the combustion chamber. To avoid misfiring, for example, BMW's engineers have developed a specific gas cycle and injection strategy, with the Vanos camshaft adjustment system regulating the share of residual gas according to specific, on-demand requirements.
And before the hydrogen/air mixture is able to flow into the cylinders, the combustion chambers are cooled by air to ensure that the fuel/air mixture is not able to ignite in an undesired, uncontrolled process.
Additional valves monitor the pressure of gas in the fuel pipes leading to the engine: Cold low-temperature valves inside the tank control the removal of hydrogen from the tank itself. Should any of the pre-flow pipes develop a leak, with supply pressure dropping below 0.4 bar, the fuel supply valves closes automatically, disconnecting and sealing the tank off from its surroundings.
The H2R’s monocoque aluminium spaceframe, entire chassis and suspension system was carried over from an undisclosed BMW production model. The front suspension is based on a double-wishbone spring strut front axle together with rack-and-pinion steering, aluminium track control arms, a tiebar, and an anti-roll bar. The front axle subframe is formed by a welded aluminium structure made up of extrusion-pressed profile bars and plates holding all front axle components and bolted to the body at six points. The track control arm made of forged aluminium comes complete with two ball joints in the interest of precise wheel guidance and directional stability.
Measuring 5,40 metres in length and two metres in width, the body of the car has a drag coefficient of 0.21. At the rear, a 20-centimetre-long diffuser prevents air swirl behind the car. The outer skin is made of carbon-fibre-reinforced plastic and the overall weight of the H2R with a full tank and the driver at the wheel is 1560 kg.