Porsche 911 Carrera 4 Brochure & Specs page 23

Air intake system.
Benefits of this include higher
torque at low engine speeds and
All models have a two-stage a flatter torque curve.
resonance intake system, which
uses the vibration of the air as
it passes through the intake
manifold to increase the intake
volume. The system can adjust
to engine speed.
911 Carrera S with sports exhaust
The entire intake system is made
from lightweight plastic. The
air-filter housing of the 3.8-litre
engine has a variable geometry
that brings added character to
the engine sound which becomes
much more aggressive at higher
rpm.
Exhaust system.
Thanks to advances in emissions
technology, they are able to meet
The stainless steel exhaust system strict emission standards, such
comprises two independent as Euro 5 in Europe and LEV II in
and separate exhaust tracts. Its the USA.
catalytic converters are highly
temperature-resistant and heat Using stereo lambda control, two
up rapidly for effective emissions sensors continuously monitor the
reduction. exhaust gas composition for each
exhaust tract. A further sensor
monitors the efficiency of the
catalytic converters.*
The 911 |
Engine
911 Carrera S exhaust system
In addition, a sports exhaust
system is available as an option
(p. 48, 150). This can be activated
as desired using a button on the
centre console.
* Not in markets with leaded fuel.