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The 911 GT2 |Drive
Exhaust system.
The rear silencer and tailpipes
of the 911 GT2 are made from
ultra-lightweight titanium to re-
duce the weight on the rear axle,
and improve driving dynamics.
The exhaust leaves the engine
through high-performance
manifolds into separate tracts
for each of the two banks of
cylinders. Twin three-way catalytic
converters clean the two streams
before they converge in the main
silencer unit. The twin
titaniumtailpipes are fully integrated
within
the rear apron moulding. Large-
diameter tubes reduce back-
pressure
on the engine,thereby
increasing performance. The
catalytic
converters are close
to the engine,
enabling faster
warm-up and therefore improving
efficiency. When starting from
cold, the process is assisted by a
secondary air injection system.
A system of ‘Lambda’ or oxygen
sensors in each of the exhausts
provides continuous monitoring of engine efficiency. Data supplied
by one pair of sensors enables
the engine management system
to perform separate adjustment
of the air/fuel mix for each bank
of cylinders. A further pair of sen-
sors*, one on each tract, is used
to monitor the efficiency of the
respective catalytic converter. This
facility enables much more accu-
rate control of potentially harmful
emissions.
The exhaust system on the
911 GT2 produces a warm,
deep and bass-rich sound –
even when the engine is idling.
Fuel system.
Fuel is supplied to each of the six
cylinders using a sequential fuel
injection system. The timing of
each injection and the volume
supplied to each bank of cylinders
are controlled by the engine
management system. Adjustmentsare based on a range of variables,
including throttle position, engine
speed, boost pressure, coolant
temperature and exhaust gas com-
position. The results are optimised
combustion and fuel consumption.
A hot-film air mass sensor moni-
tors the volume and density of the
incoming air to ensure the best
possible air/fuel mix, regardless
of weather and altitude.
Ignition system.
The 911 GT2 features static
high-voltage ignition technology.
Separate coils on each of the
plugs with platinum electrodes
ensure perfect ignition every
time. The role of distributor is
performed by the engine manage-
ment system, which controls the
individual spark plugs directly,
for optimum performance and
minimum fuel consumption.
* Not in markets with leaded fuel.Exhaust system
