Direct fuel injection (DFI).
On the 911 Turbo models, DFI
injects the fuel with millisecond
precision directly into the com-
bustion chamber at up to 140 bar
via electromagnetically actuated
injection valves, thus ensuring homogeneous distribution of the
air/fuel mixture and consequently
ef ficient combustion.
In the direct injection system, the
EMS SDI 3.1 engine management
system adjusts the injection
timing individually for each
cylinder and the injection quantit y
for each cylinder bank. This
optimises both the combustion
curve and fuel consumption.
Dual injection is implemented
at engine speeds of up to
3,200 rpm and triple injection up to 2,700 rpm to ensure faster
catalyst warm up after a cold
start and more torque in the
upper load range. The required
quantit y of fuel is distributed to
t wo or three successive injection
processes per cycle. DFI improves the internal cooling
of the combustion chamber by
forming the mixture directly in the
cylinder. This has made it possible
to increase compression (9.8
: 1),
resulting in more engine power
and even greater efficiency.
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. It also has additional
cooling functions.
The oil tank is located in the
engine, thereby eliminating the
need for an external oil tank.
A total of seven oil pumps ensure
the supply of oil. Six of those
return the oil from the cylinder
heads and exhaust gas turbo -
chargers directly to the oil sump
where a seventh oil pump feeds
oil directly to the lubrication
points in the engine.
To reduce drive losses and
increase ef ficiency, an electronic
on - demand oil pump is used.
This means that the oil pump is
operated at high power when
there is high demand and at low
power when there is low demand.
The result is an optimised oil
supply appropriate to require -
ments, lower fuel consumption
and fewer emissions.
Performance | Engine
· 32 ·· 33 ·
Brakes.
On a 911 Turbo, there is one thing
above all else that both the accel-
erator and brake pedals deliver
when you press them – and that ’s
excitement.
The standard braking system of
the 911 Turbo models features
six-piston fixed calipers at the
front and four-piston fixed calipers
at the rear. The red-painted calipers have a
monobloc (one-piece) aluminium
construction of fering greater
stabilit y, bet ter ‘bite’ characteris -
tics under heav y braking and a
further reduction in unsprung
weight. The brakes are quick to
apply and release, whilst the
pedal travel is short and the bite
point precise and consistent.
The front and rear discs have a
generous diameter of 350 mm.
All four discs are cross- drilled for
bet ter performance in the wet.
The distinctive drill-hole pat tern
enables a faster response by
allowing rapid dispersal of the
water vapour generated under
braking.
The discs are also internally
vented for bet ter heat dispersal.
The result: excellent stabilit y in
all conditions. Cooling air is
directed onto the brakes to further
improve performance. A powerful
9-inch tandem brake booster unit
enables easier pedal inputs.
Braking distances are further
reduced with the aid of t wo
functions in the standard Porsche
Stabilit y Management (PSM):
electronic brake prefill and brake
assist (page 57). The new 911 Turbo S models
come equipped with the Porsche
Ceramic Composite Brake (PCCB,
see following pages) as standard.
Standard front brake (911 Turbo)
Responsibility
| Safet y
· 66 ·· 67 ·
