2004 PORSCHE 911 TURBO cooling

· 13 ·The new 911 Turbo |
The new 911 TurboThe new 911 Turbo |The new 911 Turbo
In 1905, the Swiss engineer,
Dr. Alfred Büchi, filed the first ever
patent for a turbocharged piston
engine. The fundamental principle,
now a century old, remains
unchanged to this day: to use the
energy latent within the exhaust
flow from the engine to increase
overall performance.
The first turbocharged engine
was built in 1910 by the firm of
Murray-Willat. The concept was
embraced by the aviation industry,
which required an effective means
of compensating for the loss of
power caused by reduced oxygen
levels during high-altitude flight.Porsche was among the first
to recognise other benefits of
the technology, including higher
performance potential from
relatively small displacement
engines. This would lead to
the development of powerful
new engines with very modest
dimensions and weight.
The basic principle of a
turbocharged engine is to use
the exhaust gas flow to drive a
radial turbine which in turn drives
a compressor in the air intake
tract. The rotation of the
compressor generates a higher
intake pressure, thereby delivering
a greater amount of oxygen to
the engine. With more oxygen
available, more fuel can be burnt,
and higher performance can be
achieved. The density of the
air can be further increased by
cooling it prior to combustion.
The first ‘intercooler’ device on
a production Porsche appeared
in 1977 on the 911 Turbo 3.3.
· 12 · · 11 ·
From a stroke of genius.
From strength to strength.
The new 911 Turbo.

· 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.

Lightweight design.
The six-cylinder boxer engine is
a highly compact unit offering
excellent cylinder charging and
torque characteristics as well
as optimum balance and minimal
vibration. With the cylinders
arranged horizontally on either
side of the crankshaft, the
layout is key to the car’s low
centre of gravity.
The alloy crankcase consists
of two main sections, each
containing one bank of cylinders.
The crankshaft runs in eight main
bearings and is driven by forged
connecting rods. For optimum
durability, we’ve used forged
aluminium pistons running in
Nikasil-coated aluminium liners
and featuring individual oil-spray
cooling. Key benefits include lower
frictional resistance and longer
service life.
The cylinder heads are made
from a lightweight alloy which
is extremely resistant to high
temperature. Each bank of
cylinders has two overhead
camshafts driving a set of four
valves – two inlet and two exhaust
– on each individual cylinder.
The valves are arranged in a ‘V’
configuration and feature a highly
efficient dual-spring design.
Engine performance is further
enhanced with the aid of bothVariable Turbine Geometry (VTG –
see page 32) and VarioCam Plus
(variable valve timing and lift
on inlet side – see page 38). The
benefits are not only greater
power and torque, but also better
fuel economy and lower emissions.
Dry-sump lubrication.
This classic dry-sump system
with separate oil reservoir
ensures consistent oil pressures
throughout the engine. In doing
so, it compensates for even the
most extreme and prolonged
gravitational loads.
After passing through the engine,
every drop of oil is returned
directly to the external reservoir.
The flow is driven by two pairs of
scavenge pumps in the cylinder
heads and a further two pumps in
the crankcase. Gas is removed
from the returning oil by means of
a defoaming device in the
reservoir. As a result, the oil
level in the reservoir remains
virtually constant at all times.
The oil is returned to the
lubrication points in the engine
by means of a dedicated
oil-feed pump. With a further
scavenge pump in each of the
twin turbocharger units, the
new 911 Turbo has a total of nineseparate pumps to drive the
lubrication system.
The oil level can be checked from
inside the car via the standard
on-board computer. This solution
is not only cleaner and more
convenient than a conventional
dipstick, it is also significantly
more accurate.
· 30 ·· 31 ·The new 911 Turbo |
Drive
Main rotating assembly and valve gear

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

The rear axle assembly is a race-
proven design featuring multi-link
LSA (Lightweight, Stable, Agile)
subframe-based suspension. Its
lightened construction provides
exceptional dynamic properties.
The axle kinematics improve
stability under acceleration by
reducing excessive compression.
The lightweight strut has an
aluminium damper instead of
conventional steel to help improve
handling and agility.
Combined, the suspension enables
smooth high-speed manoeuvres
in all road and track scenarios.
Pitch and roll are reduced to a
· 53 ·The new 911 Turbo |
Chassis
To transmit power with optimum
efficiency, the front and rear
suspension must be a s stable,
and as light, as possible.
Reducing weight, particularly on
the unsprung masses, brings
major benefits in terms of driving
dynamics.The new 911 Turbo is equipped
with an electronic damping
system as standard. For more
information on Porsche Active
Suspension Management (PASM),
see page 56.The independent front suspension
combines McPherson-type struts
with longitudinal and transverse
links. Each front wheel is preciselylocated, ensuring excellent
handling and directiona l stability.
Brake spoiler elements provide
efficient cooling for each of the
front brake units.
· 52 ·Front axle 911 TurboRear axle 911 Turbo
Suspension.
Precision, strength and lightweight design.
minimum, as are tyre noise and
vibration. Overall, the car offers
a level of stability that is equal to
the car’s performance potential.

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.

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