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Water pistol fires up BMW M engine

MotoGP safety car debuts new water injection system for BMW M cars.

This is the new MotoGP safety car - a BMW M4 Coupé, which continues a 16-year tradition of BMW being the official vehicle supplier to the MotoGP series. It features all the usual mod-cons to better help it make a nice view for Valentino Rossi of a Sunday afternoon - carbon fibre boot spoiler, LED red emergency lights on the roof and a gorgeous swoop of the classic BMW M red, blue and purple racing colours. It also has water injection.

Being heavily trialled for road car use, the MotoGP safety car is now a mobile test bed for the latest BMW innovation to make its M engine faster and more powerful, but also more efficient.

It's a water injection system (fed from a five-litre tank in the boot) that sprays a fine, atomised mist of cooling water into the intake manifold during combustion. What does that do? What it says on the tin - it cools, and this has a profound effect. Turbo engines tend to run hot, sometimes too hot, which brings them close to engine knock (when the cylinders overheat and the fuel combusts out of control), the only solution to which is to wind back the power and let everything cool down a bit.

Or squirt in some water. The cooling effect reduces the onset of knock, meaning that the turbo can be cranked up for, yup, more power. The fact that the water cools down the air going into the cylinders, making it more dense, also has a beneficial effect on fuel economy, as well as helping to reduce harmful Nitrous Oxide (NOx) emissions.

Better again, the cooler air means less wear and tear on components like the turbo and catalytic convertors, which should help to extend engine life.

Anything else?

BMW is dropping massive, clanging hints that this technology will be introduced on its road cars but it isn't yet saying when or by how much it might improve power or reduce fuel consumption. A spokesperson said: "The letter "M" is not only synonymous with success on the racetrack, but also with uncompromising high-performance, street-legal sports cars. The BMW M4 MotoGP Safety Car allows BMW M Division to underline its innovative prowess and to follow the brand's philosophy of bringing motorsport technology to the streets."

Published on February 12, 2015
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