2004 PORSCHE 911 TURBO steering

· 22 ·
provide effective protection
against stone chips.
Elegantly matched to the exterior
of the car is the all-new wheel
design. The 19-inch forged alloys
have a standard two-tone finish
as well as wide, low-profile tyres.
The standard tyre dimensions
are 235/35 ZR 19 (front) and
305/30 ZR 19 (rear).
The interior of the car is equally
compelling and entirely designed
around the driver. The high-quality
surfaces include a full leather
finish on the standard electric
seats as well as the dashboard,
doors and rear side panels. Two
sports seat options are also
available, one featuring adaptive
adjustment. The standard
equipment package includes a
new gear-knob design – created
exclusively for the 911 Turbo –
· 21 ·The new 911 Turbo |
The new 911 Turbo
The extreme capability of the new
911 Turbo is elegantly enclosed in
a highly distinctive exterior. While
signalling the unique athleticism of
the car, it remains unmistakably 911.
The aerodynamics are exceptionally
well balanced, with positive
downforce at the rear. The drag
coefficient is remarkably low
at just 0.31. With its streamlined
shape and lightweight build,
the new 911 Turbo offers excellent
fuel economy as well as super-
lative performance.The standard Bi-Xenon headlights
with integral cleaning system
are compact, stylish and elegantly
incorporated within the new
front-end design. The front apron
moulding is an entirely new
development, featuring high-
performance LED indicators in
the outer air intake ducts. The
compact front foglights are
neatly positioned on the outer
edges of the front apron.
The side air intakes, to the rear
of the doors, provide optimum air
delivery to the twin intercoolerunits. Equally efficient are the
cooling air ducts to the front and
rear brake assemblies. This
enhanced cooling action is an
important factor in the excellent
performance of the standard
braking system.
The body of the car is much wider
across the rear than the front. A
generous wheel track is combined
with wider tyres to achieve
enormous lateral grip. The engine
lid is another totally new design
and features an integral bi-plane
rear spoiler. The
upper wing
element is automatically
raised at
approximately 120 km / h (75 mph)
and lowered at around 60 km / h
(37 mph).
The rear apron moulding has also
been redesigned to blend with
the rest of the car. The side air
outlets and fully enclosed twin
tailpipes are a further indication of
the power within. Black plastic
sills along the sides of the body
· 20 ·
Some say power is all about muscle.
For us, it starts with the mind.
Drive
Poised for action, yet always relaxed.
Designing the new 911 Turbo.
Rear wing retracted
Rear wing deployed
and a three-spoke sports steering
wheel featuring 40 mm of height
and reach adjustment.
The overall design of the
new 911 Turbo marks another
new phase in the ongoing
evolution of this remarkable car.
Wholly integral to the fundamental
vehicle concept, every detail
is a direct expression of power,
composure and comfort.

· 26 ·The new 911 Turbo |
Drive
· 25 · · 24 · · 23 ·
7. Exhaust-gas turbocharger
with Variable Turbine
Geometry (VTG)
8. Intercoolers
9. Pressure pipe
10. Throttle valve
(electronically actuated)
11. Exhaust system
12. Oil filter
13. Engine oil reservoir
(dry-sump lubrication)
1. Radiator module (left)
2. Radiator module (centre)
3. Radiator module (right)
4. Coolant pipe
5. Coolant expansion tank
6. Air filter
14. Generator
15. PASM damper
16. Tandem brake booster
17. 6-speed manual gearbox
18. Front differential
19. Fuel tank1. Oil scavenge pump
2. Oil-pressure pump (obscured)
3. Engine oil reservoir
(dry-sump lubrication)
4. Camshaft adjuster (VarioCam Plus)
5. Intake camshaft
6. Tappets (with hydraulic valve
clearance adjustment)
7. Valve springs
8. Intake valves
9. Nikasil-coated cylinder bore
10. Forged aluminium piston
11. Forged connecting rod
12. Crankshaft
13. Camshaft drive chain
14. Camshaft drive chain tensioner
with guide rail
15. Single-spark ignition coil
16. Spark plug
17. Exhaust-gas turbocharger with
Variable Turbine Geometry (VTG)
18. Exhaust system
19. Catalytic converter
20. Pressure pipe
21. Throttle valve (electronically actuated)
22. Plenum chamber
23. Ancillary drive belt
24. Fluid reservoir for
power-steering system
1
2
3
4
5
21
2019
19
9
6
23
24
16
11
12
14
13
22
15
17
7810
18
16
1
2
6
5
3
109
8
7
15
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18
19
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4
11
8

are reduced thanks to lengthy
replacement intervals for both
the engine oil (18,000 miles) and
air filter unit (36,000 miles). The
spark plugs require changing after
36,000 miles or a maximum of
every four years. The generator,
power-steering pump and air-
conditioning compressor are all
driven by a single self-adjusting
belt with a service life of 54,000
miles. The hydraulic tappets
provide automatic adjustment of
all valve clearances, while the
drive chains on the camshafts
and auxiliary shafts will also last
the life of the car.
Basic servicing is required after
18,000 miles or a maximum of
two years on the road. The first
major service is due at 36,000
miles or every four years at the
latest. The results: lower running
costs and virtually uninterrupted
enjoyment from your Porsche.
Exhaust system.
The exhaust system on the
911 Turbo is made from highly
durable stainless steel. The
system consists of two separate
tracts, one for each bank of
cylinders. The catalytic converters
are extremely heat-resistant,
yet quick to reach temperature
(and thus optimum performance)
when the engine is started
from cold.Twin lambda sensors in each of
the exhausts enable continuous
monitoring of the combustion
process. An additional pair of
sensors* is used to measure
the efficiency of the catalytic
converters.
Servicing.
Another pleasant surprise on the
new 911 Turbo is the standard
service schedule. Running costs
The new six-speed manual
gearbox in the 911 Turbo is
specifically adapted to the car’s
high levels of engine torque.
Designed primarily for sports
driving, one immediate
characteristic is the perfectly
judged spread betweensuccessive ratios as you upshift
through the gears. The gearshift
throw is short and precise,
with only minimal force required.
Thanks to a dual-mass flywheel,
this uncompromising setup means
there’s never any compromise
in comfort. The linkage provides
a direct connection with the
gearbox while insulating
the lever from engine vibration.
One final detail – the new gear
lever design – is exclusive to
the 911 Turbo.
· 44 ·· 45 ·The new 911 Turbo |
Drive
Six-speed manual gearbox.
Superlative power requires equal precision.
Gear lever exclusive to 911 Turbo* Not in markets with leaded fuel.

Tiptronic S also includes a warm-
up function designed to minimise
exhaust emissions. When the
car is started, the engine speed is
increased so that the catalytic
converters reach their optimum
operating temperature within the
shortest possible time. braking on descent. This, of
course, helps to reduce the
load on the braking system. If
traction is lost under braking
in the wet or on snow, the system
automatically changes up to
restore lateral grip and bring the
car back into line. there is no need to use a kick-
down function. Unlike conventional
automatic systems, Tiptronic S
does not shift up when the throttle
is released, thus enabling
optimum acceleration when exiting
a corner with no loss of stability
due to changes in load. Mid-corner
gearshifts are also prevented,
thereby enhancing stability and
safety. Under heavy braking, the
system shifts down, using engine
braking to slow the car. The
function is enabled during high-
performance use when the driver
releases the throttle to apply
the brake within a period of
1.5 seconds. These active
downshifts enhance the car’s
performance, particularly when
braking for a corner. Under
prolonged braking, additional
downshifts are performed based
on the amount of brake force
applied. An incline sensor
improves uphill acceleration and
makes better use of engine
The 911 Turbo is available with
optional five-speed Tiptronic S
offering a highly rapid gearshift
action. This versatile option offers
fully automatic five-speed
operation as well as direct manual
control.
In manual mode, you can change
gear by hand using gearshift
controls on the steering wheel.
Simply press up to change up,
and down to change down. The
clutch function is fully automatic.In automatic mode, the standard
gearshift pattern, designed
for maximum fuel economy, can
be steplessly varied up to a
dedicated ‘Sport’ configuration
for optimum high-performance
driving. Each gearshift point is
automatically selected based on
current driving style and road
conditions. Within a short space
of time, you’ll develop a feel for
the system and begin to influence
gearshifts using the throttle alone.
The benefits of Tiptronic S are
particularly apparent when
exploring the car’s potential. Even
in automatic, the rapid gearshift
action enables remarkable agility
under acceleration. The imme-
diacy of response, with virtually
no interruption in drive, is now
more than comparable with a
Porsche manual gearbox. At just
3.7 seconds, the new 911 Turbo
with Tiptronic S is 0.2 seconds
quicker to 100 km / h (62 mph)
than the standard manually
equipped car.
While still in automatic, you can
change gear by hand using the
rocker controls on the steering
wheel. If there is no manual input
for a period of 8 seconds,
the system reverts to automatic
mode.
If the car is driven more assertively,
the system automatically selects
the ‘Sport’ gearshift pattern, i.e.,
· 46 ·· 47 ·The new 911 Turbo |
Drive
Tiptronic S gear selector lever Tiptronic S control on steering wheel
Tiptronic S.
Manual and automatic in one versatile solution.

using the automatic brake
differential (ABD) function. For
optimum traction, manual gearbox
cars can also be equipped with
an optional mechanical limited-slip
rear differential (see page 56).
Assisting PTM is a new and
specially uprated version of
Porsche Stability Management
(PSM – see page 58). Combined,
these systems ensure optimum
torque distribution – and thus
optimum drive – in every type of
road scenario, including high-
speed straights, hairpin bends and
challenging, variable-grip surfaces.
Under heavy braking where ABS
is required, the multi-plate clutch
severs all front drive so that
each front wheel can be controlled
separately
by the ABS without
being influenced by the rear wheel
dynamics.
The traction benefits of the new
electronically controlled system
are particularly apparent in
the wet or on snow. In these
conditions, the new 911 Turbo
offers breathtaking acceleration.
In short, PTM offers greater
active safety, greater performance,
and even more of the positive
handling and agility you’d expect
from a 911 Turbo.
· 49 ·The new 911 Turbo |
Drive
differential (ABD) and anti-slip
regulation (ASR).
The electronically controlled clutch
is used to vary the drive torque
transmitted to the front axle. The
previous 911 Turbo had a multi-
plate clutch filled with a viscous
fluid, which ‘passively’ determined
the front/rear torque split. On
this latest evolution, the fluid is
replaced by active, electronic
control.While the viscous-fluid system
responds to relative differences in
front/rear axle speed, the new
electronic clutch offers a more
direct response to changing road
scenarios. The status of the car
is continuously monitored with the
aid of on-board sensors. These
are used to measure a range of
values, including the rotational
speed of all four wheels, the lateral
and longitudinal acceleration of
the car, and the current steering
angle. The sensor data is analysed
in ‘real time’ by PTM, enabling
immediate adjustments in front-end
drive torque as and when required.
If, for example, the rear wheels
lose traction under acceleration, a
greater proportion of drive torque
is automatically transmitted to
the front axle. The integral ASR
function is also used to minimise
wheel-spin. When
cornering,
the system controls drive to the
front wheels in order to maintain
optimum lateral grip. On variable-
grip surfaces, traction is enhanced
· 48 · Electronically controlled multi-plate clutchAll-wheel drive system
Genuine high performance calls for
more than just a powerful engine.
It also requires an effective means
of applying that power to the road.
On the 911 Turbo, this is achieved
by means of permanent all-wheel
drive and an all-new version of
Porsche Traction Management
(PTM). The key mechanical feature
within the AWD system is the
electronically controlled multi-plate
clutch. Integral functions within
PTM include an automatic brake
Electronically controlled all-wheel drive with Porsche Traction Management (PTM).
The intelligent application of power and torque.

The power-assisted steering is
not only sensitive and direct,
it also offers accurate feedback
from the road. Minimal driver
effort is required when parking,
while the turning circle is small
at just 10.9 metres – despite
the generous tyre width.
One of the key features of
the new steering system is thevariable-ratio gearing. Around the
straight-ahead position, the ratio
is less direct, enabling smoother
manoeuvres on the motorway. It
also reduces the risk of excessive
steering inputs which could
destabilise the car at high speed.
Turn the wheel harder and
the ratio becomes more direct,
enabling better manageability
through low-speed corners as well
as easier parking manoeuvres.
In all scenarios, the system
provides excellent feedback
while complementing the car’s
natural agility.
In short: all the precision of a
race-proven system, yet perfect
for everyday road use.
· 54 ·· 55 ·The new 911 Turbo |
Chassis
Wheels.
The final elements in the drivetrain
system are, of course, the
wheels and tyres. On the new
911 Turbo, we’ve used 19-inch
forged alloys as standard. The
front wheel dimensions are
8.5J x 19 with
235/35 ZR 19
tyres. Rear wheel size is 11J x 19
with 305/30 ZR 19 tyres. The
new wheel design features a
special two-tone look for even
greater visual impact. The sides
of each spoke have a titanium
paint finish, while the entire front
surface, including the flange, has
a polished finish.
Tyre Pressure Monitoring (TPM),
included as standard equipment,
provides early warning of
tyre pressure loss. The driver is
i
nformed via the on-board
computer display as well as a
separate indicator light.A range of optional 18 and 19-inch
winter wheels (all snow chain-
compatible) are available from
Porsche Tequipment. Vehicles
equipped with the optional
Porsche Ceramic Composite
Brake (PCCB) may only be fitted
with 19-inch winter wheels.
19-inch Turbo wheel
Steering.
Accuracy, comfort and excellent road contact.

This latest evolution of Porsche
Stability Management (PSM)
provides automatic assistance in
critical road scenarios. A powerful
driver aid, it uses a range of
sensors to monitor the direction,
speed, yaw velocity (speed of
rotation around the vertical axis)
and lateral acceleration of the car.
With this information, it can
then calculate the actual direction
of travel. If the car begins to
oversteer or understeer, PSM
applies selective braking onindividual wheels to bring it safely
back into line. Whenever PSM is
required to intervene, an indicator
light in the cockpit is illuminated.
Another scenario in which PSM is
invaluable is when applying the
throttle on wet or other low-grip
surfaces. Here, PSM uses the ABD
(automatic brake differential) and
ASR (anti-slip regulation) functions
in PTM to maintain traction and
stability.Standard equipment on the
911 Turbo, PSM assists with high-
precision inputs that enhance the
athleticism and agility of the car.
When ‘Sport’ mode is selected
on the optional Sport Chrono
Package Turbo (see page 60),
the PSM threshold is raised
higher still enabling greater driver
involvement – particularly
at speeds of up to 70 km / h
(44 mph).
The integral ABS ensures shorter
braking distances in critical road
scenarios. System inputs are
smooth and precise fo r greater
driver comfort. Active safety is
further enhanced with the aid of
two additional brake functions:
electronic brake prefill and brake
assist.
The prefill function is automatically
enabled whenever the throttle
pedal is suddenly released. The
pressure in the brake lines is
marginally increased, bringingeach of the pads into light contact
with the corresponding disc. If
the driver then decides to use the
brakes, the system can apply
the maximum force with virtually
no delay.
The brake assist function is
specifically designed for use in
emergency stops. When the
pressure on the brake pedal
exceeds a predefined threshold,the brake assist function uses
the PSM hydraulics to apply the
pressure required for maximum
deceleration. The result: shorter
braking distances.
For a more natural drive, PSM can
be manually disabled leaving only
the automatic brake differential
(ABD) in place. Although essentially
inactive, PSM remains present in
the background and can intervene
immediately under heavy braking
where at least one front wheel
requires ABS assistance. In ‘Sport’
mode, PSM will only respond
when ABS is active on both front
wheels.
In short, PSM provides the ideal
balance between electronically
assisted active safety and
freedom to enjoy the car’s
potential.
· 58 ·· 59 ·
Oversteer without PSM Oversteer with PSM
Car steers off line
Car steers off line PSM corrects
steering and
stabilises car
PSM corrects
steering and
stabilises car
Understeer without PSM Understeer with PSM
The new 911 Turbo |Chassis
Porsche Stability Management (PSM).
Enhanced stability control for the new 911 Turbo.

Complementing the front airbags
is the latest generation of Porsche
Side Impact Protection (POSIP).
This comprehensive package
includes two additional airbags for
each front seat: a thorax airbag
in the side of each backrest,
and a head airbag located in each
door. Each side airbag has anapproximate volume of 8 litres,
ensuring maximum protection
over the entire seat adjustment
range. Also incorporated within
the POSIP package are side-
impact protection beams in the
doors.Other standard features include
integral head restraints, an
energy-absorbing steering column,
height-adjustable three-point seat
belts with pre-tensioners and
force limiters, energy-absorbing
structures in the dashboard area
and flame-retardant materials
throughout the interior. The new 911 Turbo has a unique
passive protection system
featuring six separate airbags.
The full-size front airbags for
driver and front passenger have
a two-stage inflation capability.
With this technology, the
deployment of each airbag is
dependent on the force and
nature of the accident (e.g.,
frontal or diagonal impact). In
a low-speed crash, the airbag
is only partially inflated, thereby
minimising discomfort to the
occupants.
The airbag control unit is located
in the centre tunnel where it
receives additional information
from a pair of impact sensors near
the headlights. This arrangement
enables faster and more accurate
evaluation of impact forces in the
event of a crash.
· 74 ·· 75 ·The new 911 Turbo |
Safety
Passive safety: airbags.
Added side protection with intelligent deployment.