2013 PORSCHE BOXSTER S cooling

3233For fuel consumption, CO2 emissions and efficiency class please refer to page 131.
converter to reach normal operating
temperature 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.
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 cataly tic
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.

3435For fuel consumption, CO2 emissions and efficiency class please refer to page 131.
Fo r w ar d t h r u s t |
Engine
To reduce power losses and increase
ef ficiency, 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
em issio ns.
The oil tank is located in the engine,
thereby eliminating the need for an exter
-
nal oil tank which saves both space
and weight.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.
This results in instant acceleration and
extremely smooth running.
In short, VarioCam Plus provides
extraordinary power with comparatively
low fuel consumption.
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. VarioCam Plus.
VarioCam Plus is a two-in-one engine
concept for adjusting the intake
camshafts and switching the lift of
the intake valves.

2
1
36
37Fo r w ar d t h r u s t |
Engine
For fuel consumption, CO2 emissions and efficiency class please refer to page 131.
1 Boxster tailpipe
2 Boxster S t win tailpipemonitors 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 Boxster
models is the sports exhaust system
including sports tailpipe. It produces an
even more resonant Porsche sound.
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 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
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.