2004 PORSCHE 911 TURBO clutch

To apply these benefits efficiently
to the road, we required another
innovation in sportscar design: all-
wheel drive with Porsche Traction
Management (PTM). Using an
electronically controlled multi-plate
clutch, this intelligent technology
provides variable drive to each
axle. The front/rear split is con-
tin
uously adjusted based on current
road conditions and driver inputs.
Although biased towards the rear,
the front receives more power
whenever the situation requires.
Porsche Traction Management
is specifically designed to
optimise driving dynamics. The
additional traction provided by
both the all-wheel drive system
and PTM represents a major
improvement in active safety,
especially in the wet or on snow.
Another benchmark technology
on the new 911 Turbo is the
standard braking system. The
front and rear discs have a
generous diameter of 350 mm.On the optional Porsche Ceramic
Composite Brake (PCCB), the
front diameter is increased to
380 mm.
Other standard features on the
new 911 Turbo include a new
evolution of Porsche Stability
Management (PSM) as well as
Porsche Active Suspension
Management (PASM) featuring
electronic damper control.
A
limited-slip differential is available
for the rear axle as an option.
For even greater performance, the
car can be equipped with the
optional Sport Chrono Package
Turbo. Key features include
an ‘overboost’ function which
provides as much as 60 Nm
of additional torque under
acceleration. When the throttle
is fully open, the boost pressure
is increased temporarily by
approximately 0.2 bar. The
electronic throttle map is
also adjusted to give a more
dynamic response to pedal
inputs.
Other modifications when ‘Sport’
mode is selected include a major
rise in the trigger threshold used
by Porsche Stability Management
(PSM). The all-wheel drive system
featuring PTM provides a similar
increase in driver involvement
by sending a greater proportion
of drive torque directly to the
rear wheels. PASM provides a
stiffer suspension setup enabling
faster turn-in and better road
contact.
Another major development
on the new 911 Turbo is the
car’s lightweight design and
construction. The doors and front
lid are made from aluminium
which offers a range of benefits
in terms of both performance
and economy. Every gram of
weight on every component
is there for a specific reason.
As a result, the standard model (with six-speed manual gearbox)
weighs just 1,585 kg. Even more
impressive are the power-to-
weight ratio of 302.8 bhp per
tonne and surprisingly low fuel
consumption.This powerful potential is, of
course, matched by exemplary
ride quality on every type of
road. This rare combination of
performance and comfort is one of the distinguishing features
of the 911 Turbo.
· 18 ·· 19 ·The new 911 Turbo |
The new 911 Turbo

Engine cooling.
The 911 Turbo engine features
cross-flow water cooling with fully
integrated coolant management.
This technology ensures a
consistent flow of coolant to each
of the engine’s cylinders. All
coolant passages are integral to
the block, thus eliminating the
need for external hoses. Each
cylinder receives a fresh supply
of coolant which has not been
pre-warmed by the engine. As well
as improving reliability, this
helps to minimise maintenance
requirements. Waste heat from
the oil is transferred to the
coolant via two oil/water heat
exchangers. The coolant is routed
through twin radiator modules
ahead of the front wheels and a
centrally placed unit in the nose.
Engine management.
Optimum performance is assured
at all times with the aid of
the Motronic ME7.8.1 engine
management system. On the new
911 Turbo, this powerful ECU is
responsible for all engine-related
functions and assemblies (see
diagram). Key among these are
the Variable Turbine Geometry
(VTG), VarioCam Plus and
electronic throttle system – one
of the essential prerequisites
for the standard Porsche Stability
Management (PSM). The results:
optimum economy, emissions
and performance, regardless of
driving style.Another important task performed
by the engine management
system is cylinder-specific knock
control. By preventing pre-ignition
at high engine speeds, this
function can avert costly damage
to the pistons and cylinders. Since
temperatures tend to vary in
different parts of the engine, each
cylinder is monitored separately.
If a risk is detected, the individual
ignition timing is adjusted.
The EU-compliant on-board
diagnostics system provides
continuous fault detection and
early warning for the exhaust
and fuel supply systems. The
resulting benefits are active
prevention of harmful emissions
as well as consistent rates of
fuel consumption.
· 40 ·· 41 ·The new 911 Turbo |
Drive
Input data Used to regulate /control
Engine management system
(Motronic ME7.8.1)
Engine load
Pressure upstream from throttle
Throttle-valve angle
Engine speed (from crankshaft)
Camshaft phase angles
Throttle-pedal position
Lambda signal
Knock sensor signal
Ignition
Fuel injection
Throttle valve
Heating elements in lambda sensors
Fuel pump
Fuel-tank venting
CAN interface to
all-wheel drive control unit CAN interface to transmissionMoment interface to Porsche
Stability Management (PSM)
VarioCam Plus
– camshaft phase angle
– valve lift control
Electronic controller for
Variable Turbine Geometry (VTG)
Bypass valve
Secondary air injection
Engine-bay fan
Starter
On-board diagnostics
Air-conditioning compressor
Interface to instrument cluster
Radiator fans
Vehicle speed
Air-conditioning settings
Engine immobiliser status
Clutch pedal switch
Ambient air pressure
Temperatures
– coolant
– airflow upstream from throttle
– engine oil
– air in engine compartment
– ambient air
Exhaust-gas temperature

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.

· 126 ·· 127 ·
Technical data911 Turbo
WeightsManual/ Tiptronic S
Unladen weight (DIN)1,585 kg/1,620 kg
Unladen weight (EC)*1,660 kg/1,695 kg
Permissible gross weight1,950 kg/1,980 kg
PerformanceManual/ Tiptronic S
Top speed310 km / h/310 km / h (193 mph/193 mph)
0 –100 km / h (0 – 62 mph)3.9 secs/3.7 secs
0 –160 km / h (0 – 99 mph)8.4 secs/7.8 secs
0 – 200 km / h (0 –124 mph)12.8 secs/12.2 secs
Flexibility 80 –120 km / h 3.8 secs/3.5 secs
(50 –75 mph) in second highest gear
Fuel consumption/emissionsManual/ Tiptronic S
In accordance with 80 / 1268 /EC as valid at time of going to press**
Urban18.8/19.8 l/100 km (15.0/14.3 mpg)
Extra urban9.5/9.6 l/100 km (29.7/29.4 mpg)
Combined12.8/13.6 l/100 km (22.1/20.8 mpg)
CO2emissions307/326 g/km
Dimensions /aerodynamics
Length4,450 mm
Width1,852 mm
Height1,300 mm
Wheelbase2,350 mm
Luggage compartment volume105 litres
Tank capacity 67 litres
(refill volume)
Drag coefficient
0.31
911 Turbo
Engine
Cylinders6
Displacement3,600 cm3
Max. power (DIN)353 kW (480 bhp)
at6,000 rpm
Max. torque620 Nm (with overboost: 680 Nm)
at1,950 – 5,000 rpm (with overboost: 2,100 – 4,000 rpm)
Compression ratio9.0 :1
Transmission
LayoutAll-wheel drive with electronically controlled multi-plate clutch
Manual gearbox6-speed
Tiptronic S (optional)5-speed
Chassis
Front axleMcPherson-strut suspension
Rear axleLSA multi-link suspension
SteeringVariable steering ratio, power-assisted (hydraulic)
Turning circle10.9 m
Brakes6-piston monobloc aluminium fixed calipers at front, `
4-piston monobloc aluminium fixed calipers at rear,
discs internally vented and cross-drilled
Vehicle stability systemPSM (updated version)
Anti-lock braking systemABS 8.0
WheelsFront: 8.5J x 19 ET 56
Rear: 11J x 19 ET 51
Ty r e sFront: 235/35 ZR 19
Rear: 305/30 ZR 19* Weight is calculated in accordance with the relevant EC Directives and is valid for standard specification vehicles only.
Optional equipment means greater weight. The figure given includes 68 kg for the driver and 7 kg for luggage.
** Provisional data only. Final data unavailable at the time of going to press.

L
Leather 104, 112
Limited-slip differential,
mechanical 56
Loudspeakers 90
LSA concept 53
Lubrication 31
Luggage compartment 84
M
Manual gearbox 45
Materials 95
MOST
®bus 90
MP3 playback 86
Multifunction steering wheel 78
Multi-plate clutch,
electronically controlled 48
N
Navigation expansion module 87
Navigations system 87
Noise 97
O
On-board computer 88
On-board diagnostics 40
Optional equipment 108
P
ParkAssist 82
Performance display 60
Personalisation 98
Porsche Active Suspension
Management (PASM) 56
Porsche Ceramic
Composite Brake (PCCB) 70
Porsche Communication
Management (PCM) 86
Porsche Side Impact
Protection (POSIP) 75
Porsche Stability
Management (PSM) 58
Porsche Traction
Management (PTM) 48
R
Rear wiper 83
Recycling 95
Roof transport system 84
S
Safety, active 66
Safety, passive 72
Seats 80
Seats, rear 81
Service 122
Servicing 44, 97
Sport button 60
Sport Chrono Package Turbo 60Sports seats 80
Sports seats, adaptive 80
Steering 54
Stereo lambda control 44
Sunroof, slide/tilt 83
Suspension 52
T
Tandem brake booster 69
Technical data 126
Telephone 89
Timer 60
Tiptronic S 46
Transmission 126
Tyre Pressure
Monitoring (TPM) 55
V
Variable Turbine
Geometry (VTG) 32
Variable valve timing 39
VarioCam Plus 38
Vehicle tracking system 84
W
Water- cooling 40
‘Welcome Home’ lighting 82
Wheels 55
Wood, macassar 115
Wood, sycamore 116
· 129 ·
A
Air conditioning, automatic 79
Airbags 74
Alloy engine 30
All-wheel drive 48
Aluminium Look 118
Antenna diversity 88
Anti-theft protection 84
Audio system 86, 119
AudioPilot
®91
Axle concept 52
Axle, front 52
Axle, rear 53
B
Bi-Xenon lighting 66
Bodyshell 72
BOSE
®Surround
Sound System 90
Boxer engine 28, 30
Braking system 68
C
Carbon 117
Catalytic converters 44
CD autochanger 89, 119
Ceramic brakes 70
Child seats 81
Colours 100
Colours, interior 104
Colours, special interior 105
Communication 119
Cross-flow cooling 40
Cruise control 83
D
Design 20
Driver memory function 63
Dry-sump lubrication 31
DVD navigation drive 87
E
Electronic logbook 89
Emissions control 94
Engine management system 40
Exhaust system 44
F
Factory collection 120
Fire extinguisher 82, 111
Foglights 67
Fuel injection, sequential 42
Fuel system 97
G
GPS navigation system 87
GSM telephone 89
H
HomeLink®83
Hot-dip galvanised sheet steel 73
I
Ignition 43
Instruments 79
Interior 78
K
Knock control,
cylinder-specific 40
· 128 ·
Index