A racing version of the M42 Engine, called the S42 is known. It was used in BMW's 320 4-door touring car, participating in the German racing series called STW (Super Tourenwagen Cup). It differed by having individual throttle bodies (ITB) for each cylinder and its capacity was enlarged to 1999 cc. It had eight fuel injectors instead of the standard four. Valve cover and
airbox were entirely made of carbon fiber. Lubrication was provided by a
dry sump system.
Compression ratio was increased and a lightweight head was installed.
Horsepower evolution steps of the S42 Engine:
Year 1995 1996 1997
300 hp 308 hp 315 hp In the last evolution step the engine puts out an amazing 158 hp/L. Compared to a modern racing engine it was a big achievement.