ignition PORSCHE 911 GT2 2010 5.G Information Manual

| 14
VarioCam Plus.
VarioCam Plus is a two-in-one
engine concept which adapts to
the particular demand for power.
The system switches seamlessly
thanks to the engine management
system. The result is spontaneous
acceleration and smoother run-
ning.
At medium revs and low engine
loads, the system reduces fuel
consumption and emissions by
lowering the valve lift settings
and advancing the timing. Fuel
economy is especially noticeable
at lower revs. High torque values
and maximum power are achieved
with the high valve lift setting,
which results in exceptional engine
power with comparatively low fuel
consumption.
Expansion intake manifold.
Essentially, in all intake systems,
as well as flowing through, the
air also vibrates. These vibrations
consist of both a compression
phase in which the air is com-
pressed and also an expansion
phase in which the air expands.
Until now, more air has meant
more power. The compression
phase of the air vibrations in the
intake system is used to press
more air into the combustion
chamber. The disadvantage is
that, when it is compressed, the
air is also heated. It is therefore
impossible to achieve optimum

ignition of the fuel and air mixture
to maximise power.The expansion intake manifold
adjusts the air vibrations in a com-
pletely different way. It uses the
expansion phase because, when
it expands, the air cools. The mix-
ture in the combustion chamber
therefore becomes cooler – and
optimum ignition can be achieved.
In using the expansion phase,
less air gets into the cylinders.
However, a slight increase
in the charge pressure by the
turbocharger compensates for
this effect. The heating of the
air caused by the higher charge
pressure is in turn compensated
by the charged air cooler. The
result is much higher efficiency
for even greater engine power
and improved fuel consumption

at high loads and engine speeds.
In principle it is quite easy to be in
awe: just breath deeply.
Power transmission.
The light weight six-speed gearbox
in the 911 GT2 RS is designed
specifically for the large amount
of engine power. The gear lever
throw is short and precise – for
rapid and precise gear changes.
Instead of a dual-mass flywheel as
in the 911 GT2, the 911 GT2 RS
uses a single mass flywheel. This
is lighter and the engine can rev
more freely in the upper speed
ranges. Also, the gear ratios have
been readjusted specifically for
use on the racetrack.