2004 PORSCHE 911 TURBO wheel torque

· 14 ·· 15 ·The new 911 Turbo |
The new 911 Turbo
The second 911 Turbo, launched
in 1977, developed 300 bhp from
a 3.3-litre intercooled engine.
Brake performance was similarly
enhanced, combining four-piston
aluminium fixed calipers with
cross-drilled discs.
In 1993, Porsche launched the
final 911Turbo to feature dedicated
rear-wheel drive. Based on the
Type 964 platform, it used a
3.6-litre engine to achieve a major
boost in output to 360 bhp.
Its Type 993 successor, launched
in 1995, set a range of new
benchmarks in supercar perform-
ance. All-wheel drive provided
greater active safety as well as
better driving dynamics. The
system also had a rear-axle bias
that retained the familiar Porsche
handling characteristics. Twin
exhaust turbochargers offered
better response and a more
harmonious build-up of power. The
last 911 Turbo to have an air-
cooled engine, it offered maximum
output of 408 bhp from a
3.6-litre displacement.
The first water-cooled 911 Turbo,
the Type 996, made its debut
in the year 2000. Also equipped
with all-wheel drive, it used
VarioCam Plus to achieve a major
improvement in all-round fuel
economy. The engine capacity
remained at 3.6 litres, while
output rose to 420 bhp fo r a
maximum speed of 305 km / h
(190 mph). The Type 996 model
was the first 911 Turbo with the
option of Tiptronic S transmission.
The subsequent launch of the
Turbo S version saw a further
rise in output to 450 bhp.
Now, the evolution of this
remarkable car has reached a
new pinnacle of achievement.
Over the following pages, we
will explore every aspect of the
new 911 Turbo.The first Porsche racing car to
feature turbocharged power made
its debut in the early 1970s. The
12-cylinder engine in the legendary
917 used a twin turbo system to
achieve a colossal 1,000 bhp
.
In 1972, the 917/10 with 5-litre
turbo engine claimed the North
American CanAm
championship.
In the following season, the
917/30, developing 1,100 bhp
from a 5.4-litre unit, became the
most powerful racing Porsche of
all time.
This invaluable race experience
inevitably found its way into our
production
road car development.
Just one year later, in 1974,
the 911 Turbo was born. Preceded
as it was by the 1973 oil crisis, it
was considered a
bold undertakingby Porsche. As history would show,
it was the first of many surprises in
the evolution of this legendary car.
The original 911 Turbo featured
widened wheel arches as well as
specially developed front and rear
spoilers. These major aerodynamic
refinements were essential
requirements given the increased
engine performance. Developing260 bhp, the first 911 Turbo could
reach 100 km / h (62 mph) in as
little as 5.5 seconds. Maximum
torque output of 343 Nm was
unprecedented in a 3-litre engine.
This exceptional performance
necessitated a new gearbox
design featuring specially
reinforced gears. Thus began a
new type of Porsche that would
soon acquire mythical status.
911 Turbo 3.0 (1974), 911 Turbo (2006)

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

Tiptronic S, the new 911 Turbo
requires just 3.7 seconds to
reach 100 km / h (62 mph), and
just 12.2 seconds for 200 km / h
(124 mph). Facilitating this
performance is the additionaltraction provided by the new
electronically controlled all-wheel
drive system (see page 48).
In appropriate track conditions,
the car’s maximum speed is
310 km / h (193 mph).
· 29 ·The new 911 Turbo |
Drive
Every 911 shares the same
fundamental engine charac-
teristics. Key among these are
the ‘flat-six’ cylinder layout
and rear-mounted installation.
There is, however, one essential
feature that is unique to the
911 Turbo. The twin turbocharger
system that gives the car its name
now includes Variable Turbine
Geometry (see page 32). Thus
equipped, the 3.6-litre engine
develops 353 kW (480 bhp) at6,000 rpm. Weighing 1,585 kg,
the standard 911 Turbo (with
manual gearbox) has an excellent
power-to-weight ratio of
302.8 bhp per tonne. Specific
power output is 133 bhp per
litre of engine displacement.
Maximum torque is a phenomenal
620 Nm, rising to 680 Nm with
the overboost function in the
optional Sport Chrono Package
Turbo (see page 60). Thanks
to VarioCam Plus (see page 38)and the new turbocharger system,
all of that torque is fully available
between 1,950 and 5,000 rpm.
The resulting acceleration is
inspirationally quick. Equipped with
· 28 · · 27 ·The new 911 Turbo |
Drive
Engine.
Heart and soul of the new 911 Turbo.
911 Turbo engine

· 36 · · 35 ·· 37 ·The new 911 Turbo |
Drive
Guide vanes open Guide vanes closedGuide vanes open Guide vanes closed
The capability of the engine can
be further enhanced by selecting
‘Sport’ mode on the optional Sport
Chrono Package Turbo (see page
60). Under full acceleration, the
boost is temporarily increased by
approximately 0.2 bar. During this
phase, the engine develops as
much as 60 Nm of additional
torque.
Matching the superlative
performance of the car is the
efficiency with which it is
generated. In spite of the increase
in power and torque, the new
911 Turbo offers a further
reduction in fuel consumption.
1
2
3
4
5
6
7
8
9
10
1. Turbine casing
2. Movable guide vanes
3. Turbine wheel4. Electric motor for guide
vane adjustment
5. Guide vane adjuster
6. Compressor casing7. Compressor wheel
8. Excess-pressure valve
9. Oil inlet
10. Coolant inlet340 500 540
580
620 660 700
220 240
260
280
300
1500
7500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000
380 420
460
1000
Power (kW)
Engine speed (rpm)
620 Nm
120 140
160
180
200
Torque (Nm)
680 Nm
740 320
340 360380780 820860
353 kW (480 bhp)
911 Turbo
911 Turbo overboost

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.

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 new 911 Turbo is a prime
example of the ongoing evolution
of Porsche engineering. For
another step up in all-round
performance, there’s the optional
Sport Chrono Package Turbo.
This integrated system provides
simultaneous enhancement
for engine, chassis and optional
Tiptronic S transmission.
Key features include a digital and
analogue timer located centrally
on the dashboard, a ‘Sport’ select
button on the centre console,
a performance display in the
standard Porsche Communication
Management (PCM), a personal
memory function in PCM, and
a special ‘overboost’ function
unique to the new 911 Turbo.When ‘Sport’ mode is selected,
the engine management system
applies a new set of variables
creating a much more aggressive
response. A modified throttle
map relates the pedal position in
the footwell to a wider angle
of opening on the throttle. As a
result, the engine has a much
more positive reaction to every
pedal input. In the higher gears,
a hard rev-limiter helps protect
the engine under power.
Under full acceleration, the
‘overboost’ function provides a
temporary increase in available
boost pressure of approximately
0.2 bar. The overboost is applied
across the medium rev range,
raising the standard 620 Nm of
torque to as much as 680 Nm.
The modified throttle is matched
by PASM, which also switches
to ‘Sport’ mode. The dampers
become firmer, enabling fasterturn-in as well as better contact
with the road.
On vehicles with Tiptronic S,
the basic gearshift pattern is
automatically switched to high-
performance mode. The gearshift
action is virtually instantaneous,
while the shift points are timed for
maximum acceleration. Lift off
the throttle – even at high revs –
and the system automatically
shifts down to apply engine
braking. There are no unwanted
upshifts in manual mode when
approaching the engine rev limit.
Since the driver has control over
every upshift, the handling of
the car is smooth and assured,
particularly when braking for a
corner.
To minimise assistance from
PSM, the trigger threshold for
this system is raised. The result
is a more natural and involving
response to both lateral andlongitudinal forces. Mid-corner
agility is considerably enhanced,
with greater scope for oversteer
on turn-in and exit. This added
freedom is particularly apparent
in lower-speed sequences and
bends. For even greater driving
pleasure, the all-wheel drive
system applies a greater
proportion of drive torque to the
rear.
· 60 ·· 61 ·The new 911 Turbo |
Chassis
‘Sport’ button on centre console
Sport Chrono Package Turbo.
Additional power, precision timing.

Porsche Communication
Management (PCM). This
comprehensive system features
satellite navigation with a
separate DVD drive in the
luggage compartment for
the single navigation disc.
The one-touch switches on the
centre console are logically
positioned for optimum ease of
use. All instruments are perfectly
placed within the driver’s field of
vision. The air-conditioning system
is fully automatic and features a
highly effective active carbon filter.
This added convenience gives
you greater freedom to enjoy the
driving experience.
The tinted front glass and generous
rear screen offer excellent fore-
and-aft visibility. The front side
windows have a water-repellent
finish, which automatically
disperses moisture and dirt.
The result: optimum visibility in
poor weather conditions.
Instruments.
The classic arrangement of five
round instruments provides a
clear overview of all key information.
The digital display in the centre-left
dial (speedometer) provides main
and trip odometer readings. The
central rev counter, featuring the
‘turbo’ logo, includes the standard
on-board computer display.
This multi-purpose field contains a
permanent digital speedometer
as well as the following optional
information: boost pressure,
average speed, average fuel
consumption, tyre pressure,
current radio station, navigation
instructions and remaining range
till empty. When ‘Sport’ mode
is selected on the optional Sport
Chrono Package Turbo, the
temporary increase in torque is
clearly indicated using an arrow
symbol in the boost pressure
display. The third display, in the
centre-right dial, contains a
clock and external temperature.
The dot-matrix technology used in
each of these displays provides
a high resolution for icons and
text. Design and legibility are
further enhanced with brilliant
white backlight illumination.
· 78 ·· 79 ·The new 911 Turbo |
Comfort
Interior.
For the pure enjoyment of performance.
The passenger compartment in the
new 911 Turbo is another example
of uncompromising design. As you
would expect, it offers the highest
standards of ergonomics, comfort
and quality. The seats, dashboard,
doors and rear side panels are
finished in leather as standard. Atthe centre of the cockpit is a new
gear lever design that’s exclusive
to the new 911 Turbo.
Other standard features include
a three-spoke sports steering
wheel offering 40 mm of
adjustment for both height and
reach. A three-spoke multi-function
steering wheel – available as
optional equipment – provides
direct access to audio, navigation
and (if fitted) telephone functions.
The standard audio package
is the latest evolution of