cooling PORSCHE BOXSTER S 2011 2.G Information Manual

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Resonance intake manifold.
The resonance effect, where the air
mass inside the intake manifold is
caused to oscillate is used to optimise
the induction process at all engine
speeds. The engine in the Boxster S is
additionally equipped with a switchable
resonance valve.
The results are high torque, a flat ter
torque curve and high power output.
The sound produced is characteristically
resonant and deep, as you would expect
of a Boxster.

Direct fuel injection (DFI).
Direct fuel injection (DFI) is featured
as standard in both Boxster models.
Multi-hole injectors deliver fuel directly
into the combustion chamber with milli -
second precision. The injection pattern
has been optimised for torque, power
output, fuel consumption and emissions.
With direct injection, the engine manage -
ment system regulates injection timing
individually for each cylinder, as well as
the injection rate for each cylinder bank.
This optimises the combustion process
and therefore fuel economy. Depending
on the engine operating conditions, multi -
ple fuel injections can take place on each operating cycle. This allows the cata
-
ly tic converter to reach normal operating
temperate sooner after a cold start and a
higher maximum torque to be achieved.
DFI improves the internal cooling of the
combustion chamber by having the
mixture prepared directly in the cylinder.
This allows for a higher compression ratio,
which helps to deliver higher power output
at the same time as enhanced engine
efficiency. Injection is regulated by the
electronic engine management system
and emissions are monitored by the stereo
Lambda sensors.
For fuel consumption and CO
2 emissions please refer to page 127.

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VarioCam Plus.
VarioCam Plus is a two-in-one engine
concept for adjusting the intake
camshafts and switching the lift of
the intake valves. The system first dif ferentiates bet ween
driver inputs that typify normal, everyday
driving and those inputs that demand
maximum performance. The electronic
engine management system then

imperceptibly adapts valve operation
to the prevailing conditions. This results in instant acceleration and
extremely smooth running.
In short, VarioCam Plus provides

extraordinary power with comparatively
low fuel consumption.

Integrated dry-sump lubrication.
Integrated dr y-sump lubrication ensures
a reliable supply of oil even when a sport y
driving st yle is adopted and the vehicle is
experiencing powerful lateral acceleration.
It also has additional cooling functions. The oil tank is located in the engine, there
-
by eliminating the need for an external oil
tank which saves both space and weight.
To reduce power losses and increase
efficiency, an electronically controlled oil
pump supplies the lubricating points
inside the engine as and when required.
This results in optimum supply of oil,
lower fuel consumption and reduced
emissions.
For ward thrust |
Engine
For fuel consumption and CO2 emissions please refer to page 127.

12
Thermal management.
The Boxster models feature a new version
of thermal management to reduce friction
losses that arise during the warm-up
phase.
Thanks to the selective control strategy
and on-demand, gradual activation of the
various cooling circuits, the engine and
gearbox warm up to normal operating
temperature more rapidly. The conse -
quent reduction in friction also reduces
fuel consumption and CO
2 em issio ns.
During sporty driving, thermal manage -
ment also acts to reduce temperatures
so that a high level of performance is
maintained. Our cross-flow cooling system, as used

in motorsport, supplies each engine
cylinder uniformly with coolant, which
protects the valves against thermal
overload and, therefore, premature wear.
This improves combustion and keeps
emissions, fuel consumption and noise
comparatively low.
Exhaust system.
In the new Boxster models, each cylinder
bank has its own stainless-steel exhaust
tract. Downstream of their respective
rear silencer, the tracts converge into
a connecting tube and a single (Boxster)
or t win (Boxster S) tailpipe. The stereo
Lambda control circuitr y controls and monitors each cylinder bank separately.
For each exhaust tract, four correspond
-
ing oxygen sensors regulate the composi -
tion of the exhaust gas and monitor the
performance of the catalytic converters.
Having separate tracts means that the
exhaust gas can flow more freely. The
resulting reduction in pressure loss has a
positive impact on power output, torque
and the unmistakable engine sound.
Available as an option for the new Boxster
models is the sports exhaust system
1)
including sports tailpipe. It produces an
even more resonant Porsche sound.
For ward thrust |
Engine
For fuel consumption and CO2 emissions please refer to page 127.
1) Not available at launch. Please consult your
Centre for availability.
1 Boxster tailpipe
2 Boxster S t win tailpipe