BMW plans to mix Valvetronic and GDI turbos

摘要

BMW is focusing development of the next generation of its variable valvetrain on combining it with homogeneous direct injection and turbocharging. It also aims to improve parts integration and packaging.rn"Variable valve lift, homogeneous direct injection and turbocharging can lower fuel consumption and emissions while retaining high specific power," said BMW. "This combination can also improve engine response."rnIts Valvetronic system usesrnan electric motor to vary the inlet valve lift. This, not the throttle, provides engine load control, reducing pumping losses.rnThe motor and adjustment mechanism are a little bulky, however. BMW wants to make them smaller and package them within the cylinder head, using engine lubricant to cool it.rnThe firm needs an electronically commutated, brushless DC motor. Even with the eccentric adjustment shaft's position sensors integrated inside, thernmotor is around 60 per cent smaller and 40 per cent lighter than current systems.