2015 BMW M4 Coupe MotoGP Safety Car

2015 BMW M4 Coupe MotoGP Safety Car 

Appearing as it does in the extremely performance-oriented world of MotoGP, where the world's top motorcycle racers battle for points and positions, the Safety Car must also boast appropriately impressive performance parameters. With this in mind, the engineers at BMW M Division have equipped the highperformance power unit with an innovative water injection, thus considerably increasing the engine's performance. Water injection makes it possible to raise the upper performance limits, which have otherwise been restricted thermally. As well as increasing performance and torque, the innovative system in the BMW M4 MotoGP Safety Car also ensures outstanding efficiency with benefits in terms of fullload consumption and exhaust emissions. As a BMW M product at the cutting edge of technology and innovation, the BMW M4 MotoGP Safety Car also opens up possibilities for use of this technology in future production models.

2015 BMW M4 Coupe MotoGP Safety Car 

The water injection system employed by BMW M Division further optimises the performance and consumption of the charged six-cylinder, inline engine at full throttle. The engineers make use of the water's physical effect during the vaporisation process to extract the energy required from the environmental medium. Water is injected into the intake module's collector as a fine spray, thus significantly cooling the exhaust air during vaporisation. This lowers the discharge temperature in the combustion changer and thus reduces the tendency for knocking. The turbo engine can thus be operated with a higher charging pressure and an earlier ignition point.

2015 BMW M4 Coupe MotoGP Safety Car 

The lower process temperatures also reduce the formation of hazardous substances, in particular nitrogen oxide (NOX). Water injection consequently dramatically improves the effectiveness of the engine. The technology increases performance and torque, whilst at the same time ensuring outstanding consumption and emission figures. As such, the improved performance can be achieved without increasing the heat applied to performance-related components, meaning the reliability of these parts is not affected.

The performance achievable by a combustion engine is limited by various factors, including the process temperature in the combustion chamber. If this temperature is exceeded, the result is uncontrolled combustion (knocking) and thus a loss in performance and, in the worst case, expensive damage to the engine. This is particularly important when the engine is charged, as the intake air is already heated intensely in the turbocharger's supercharger. An intercooler does ensure that the temperature drops as necessary, but even that has its physical limits. Depending on design and dimensions of the cooling system and the car's aerodynamics, the intake air reaches temperatures that are just below the maximum permitted temperatures.

2015 BMW M4 Coupe MotoGP Safety Car 

Increasing the supercharging pressure would exceed the knocking limit and is therefore not a viable means for increasing performance. BMW M Division has a solution: injecting a fine spray of water into the collector once more significantly reduces the temperature of the combustion air. The cooler supercharged air reduces the engine's tendency to knock, making it possible to bring the point of ignition forward and thus closer to the optimum value. This makes the combustion process more effective, whilst at the same time reducing the combustion temperature. On the other hand, cool air has a higher density which increases the oxygen content in the combustion chamber. This results in a higher mean pressure during the combustion process and in turn optimises performance and torque. Finally, the effective internal cooling of the combustion chamber reduces the thermal strain on numerous performance-related components. This not only prevents damage to pistons, exhaust valves and catalytic converters, but also reduces the strain on the turbocharger, which is subjected to lower exhaust temperatures.