BMW revives war-time engine technology

BMW says the water-injection system from its M4 MotoGP Safety Car helps produce more power while reducing nitrogen oxide and carbon monoxide emissions, and it will soon be available in production models.

Just one sip of water makes the difference in the system, which boosts power by 8-10 per cent while cutting the toxic exhaust pollutants.

But while it is currently the only car with the technology, BMW said it will offer the system on future production models, likely to be the mooted M4 GTS lightweight performance variant.

The safety car was unveiled in mid-February and will be seen in the metal this year at MotoGP events that kick off in Qatar on March 29. It will be in Australia for the 16th round of the MotoGP, to be held at Victoria’s Phillip Island in October.

BMW Group Australia general manager corporate communications Lenore Fletcher said the technology was set to filter down to road-going BMW models in the not-too-distant future.

“Other than the car shown at Geneva, all I can tell you is that the technology is being planned for future production cars,” she said.

A BMW announcement at the Geneva motor show said the M4 Coupe MotoGP safety car “will blaze a trail for technology and innovation thanks to an innovative water-injection system designed to give the engine a noticeable boost in performance”.

“This pioneering technology also enables excellent levels of efficiency even under full load with real benefits when it comes to fuel economy and exhaust emissions.” Without mentioning the war, where BMW-engined bombers and fighter planes used water injection to increase power and altitude, BMW said the system underlined the company’s experience in motor racing.

“At the same time, the car offers a very clear taster of an M automobile that promises to set a new benchmark in performance, exclusivity and individuality not too far from now,” it said in reference to the future production car.

The water injection system adds a 5.0-litre bottle in the boot. It is designed to last at least the equivalent of one tank of petrol as the water is only used at full throttle and/or in hot-weather conditions.

It works by spraying water into the combustion chamber to lower the temperature of the incoming air, making it denser and producing a more powerful and efficient burn. By reducing the air temperature it acts like an intercooler.

The cooler combustion air reduces the chances of the engine overheating and overcomes denotation. It also maximizes the engine performance regardless of ambient temperature.

The water injection system is likely to appear on BMW’s next lightweight M4 GTS, successor to the M3 GTS. GoAuto understands that the new coupe will be revealed either at Pebble Beach in California in August or the Frankfurt motor show in September.

BMW used a 50:50 methanol and water injection in its aircraft engines during World War 2, claiming a 10-20 per cent power boost for quicker take-off and high-altitude flying. It was fitted to planes including the Focke-Wulf 200 Condor for transport, long-range reconnaissance and bomber duties and the FW 190 single-seat fighter.

Cars with the system have included the turbocharged 1962 Oldsmobile F85 and the Saab 99 Turbo. The system was specifically designed for turbocharged engines but some owners tired of replacing the water. It was eventually replaced with intercoolers.

Water injection is now more commonly seen on specialised race and drag vehicles.