Porsche 911 Turbo User Handbook Manual page 19

VarioCam Plus.
Optimal valve timing, optimal valve lift.
VarioCam Plus is an innovative for normal driving, the second
system that continually adjusts tuned for high-performance road
valve timing and valve lift for and track use. The system
optimal performance. Its benefits switches seamlessly between
include increased power and torque the two in response to driver
at all engine speeds, smoother input and conditions.
running, better fuel economy and
reduced exhaust emissions. VarioCam Plus incorporates two
cam profiles into each inlet
Essentially, VarioCam Plus offers camshaft. An electro-hydraulic
two engines in one: one tuned mechanism engages the proper
cam profile for a given engine
speed. The timing of each valve
is steplessly controlled by means
of an electro-hydraulic rotary
vane adjuster at the head of the
corresponding camshaft. All
operations are managed by a
robust electronic control unit.
From the driver's perspective,
the benefits of VarioCam are
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clear: copious torque when 911 Turbo ensures ideal oil
desired, with impressive fuel pressure even under extreme
economy in daily driving, g-force loads. After passing
particularly compared to larger through the engine, every drop
engines with similar output. of oil is returned directly to an
external reservoir. Flow to the
reservoir is driven by two pairs of
Dry-sump lubrication. scavenge pumps in the cylinder
heads and two pumps in the
Oil is the lifeblood of a high- crankcase. A de-foaming device
performance engine. With a in the reservoir removes gases
classic dry-sump system, the from the oil. The oil is returned
The 911 Turbo I Performance
to the lubrication points in the
engine by means of a dedicated
oil-feed pump. With an additional
scavenge pump in each of the
twin turbocharger units, the
911 Turbo has a total of nine
separate oil pumps to assure
continuous flow.
VarioCam Plus
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