Porsche 911 - Manual (Page 21)

· 44 ·
VarioCam Plus System.
VarioCam Plus combines variable
valve timing with two-stage lift
on the inlet side. This results
in smoother running, better
fuel economy and lower exhaust
emissions. As well as greater
top-end power and low-end torque.
This two-in-one engine concept
seamlessly adapts in response
to driver input. The result: instant
acceleration and extremely
smooth running.
The variation in intake timing is
steplessly controlled by means
of an electro-hydraulic rotary
vane adjuster at the head of the
corresponding camshaft.
To improve throttle response
during the warm-up phase,
VarioCam Plus selects high valve
lifts with retarded valve timing. In
the middle and low load ranges,
low valve lifts with advanced
timing reduce fuel consumption
and exhaust emissions. High
valve lifts generate high torques
and maximum output.
· 45 ·
The new 911 | Engine
911 Carrera 4S Cabriolet
Lightweight construction.
The advantages of an alloy
engine are its low weight and
reduced fuel consumption.
Thanks to intelligent design down
to the finest detail, it has been
possible to reduce the weight of
the new generation of engines
even further, e.g. by fully integrat-
ing the camshaft bearings into
the cylinder heads.
Fuel economy has been further
improved by the optimally
designed oil supply system and
a reduction in the mechanical
friction of the engine.