BMW N55 Manual page 48

The following graphic shows the effect of the previously described measures. These
measures achieve improved and faster combustion in the red area. Technically, this is
known as the turbulent kinetic energy.
Influence of phasing and masking on flow in the combustion chamber
Index
A
B
TKE
Engine response is improved by the combination of Valvetronic III, direct injection and tur-
bocharging. The response up to naturally aspirated full load is shortened on a naturally
aspirated engine with Valvetronic as there is now no need wait for the intake air manifold
to be filled. The subsequent torque buildup as the turbocharger starts up can be acceler-
ated with the partial lift setting at low engine speed. This effectively flushes out residual
gas, thus resulting in faster torque build-up.
48
N55 Engine
Explanation
Valvetronic I
Valvetronic II and III with Phasing and masking
Turbulent knitic energy