2004 PORSCHE 911 TURBO brakes

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.

Power, torque, acceleration,
and flexibility: in every respect,
thenew911Turboismore
accomplished than ever before.
The logical adjunct to all these
improvements is a corresponding
increase in brake performance.
To achieve that capability, the
standard braking system combines
six-piston fixed calipers at the
front of the car with newly devised
four-piston units at the rear.The red-painted calipers have a
monobloc (one-piece) aluminium
construction offering greater
stability, better ‘bite’ character-
istics under heavy braking, and
a further reduction in unsprung
weight. The brakes are quick
to apply and release, while 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
better performance in the wet.
The distinctive drill-hole pattern
enables a faster response by
allowing rapid dispersa l of the
water vapour generated under
braking. The discs are also
internally vented for better heat
dispersal. The result: excellent
stability in all conditions.
Other features include four-
channel ABS offering a smoother,
low-pulse action. Brake spoiler
elements provide effectivecooling for all key brake
components. A powerful tandem
brake booster unit enables easier
pedal inputs.Braking distances are further
reduced with the aid of two new
functions in the latest evolution
of the standard Porsche StabilityManagement (PSM): electronic
brake prefill and brake assist
(see page 58).
· 68 ·· 69 ·The new 911 Turbo |
Safety
Standard brake unit
(front axle)
Active safety: braking system.
Always quick when you have to be slow.

· 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