PORSCHE 911 GT2 2008 5.G Information Manual

· 44 ·· 45 ·The 911 GT2 |
Chassis
Rear axle Front axle
The 911 GT2 chassis is designed
for racecar-like performance on
every type of tarmac from motor-
way to track. The car rides about
25 mm lower than the 911 Carrera
and its lightweight build has
reduced overall weight as well as
the unsprung masses. Agile and
responsive, it is stable and secure– particularly during cornering
manoeuvres.
The front suspension with its
special wheel mounts has
McPherson spring struts with
the wheels mounted individually
on trailing arms and wishbones.
Each front wheel is preciselylocated, ensuring excellent
handling and directional stability
in all road and track scenarios.
Brake spoiler elements provide
efficient cooling for each of the
front brake units.The rear axle assembly consists
of subframe-mounted multi-link
suspension featuring LSA con-
struction (Light, Stable, Agile).
This lightened design featuring
an aluminium cross-member
is an important factor in the
exceptional dynamics of the car.
Ride height, camber, toe angle
and anti-roll bar settings can
all be adapted to individual circuit
characteristics, as befits a racing
Porsche.There is virtually no unwanted
movement between the suspen-
sion and body, thanks to special
features such as metal bearings
with ball joints on the front strut
mounts and rigid cross-members
at the rear. This reduced elasticity
and improved wheel location
enable better handling and turn-in.
The 911 GT2 has an electronic
variable damping system as
standard – Porsche Active Suspension Management (PASM,
see page 48).
This variable
damper system offers two basic
setup modes, ‘Normal’ and
‘Sport’.
Racetrack. Motorway. Wherever the road goes.
Chassis.

· 47 · · 46 ·
The 911 GT2 |Chassis
The 911 GT2 runs on one-piece
19-inch GT2 wheels with anti-
theft protection and wheel
centre caps featuring the GT2
logo. The wheels are extremely
light for their size due to their
special lightweight construction.The resulting reduction in unsprung
masses improves driving dynamics
and performance. Thanks to the
generous internal diameter of the
wheel, large brakes can be fitted
on the front axle. The wheels run
flush with the exterior of the carand come with special sport tyres
as standard.
The wheel dimensions are
8.5J x 19 ET 53 with 235/35 ZR 19
tyres (front) and 12J x 19 ET 51
with 325/30 ZR 19 tyres (rear).The 19-inch sports tyres provide
a large road contact patch.
They offer greater traction
under acceleration and braking,
greater precision in both handling
and manoeuvrability, as well as
higher cornering speeds on dry
road surfaces. In short: even
greater driving pleasure. Note:
increased risk of aquaplaning due
to lower tread profile.Tyre Pressure Monitoring (TPM),
included as standard equipment,
provides early warning of tyre
pressure loss. The driver is
informed via the on-board com-
puter display as well as a separate
indicator light. A tyre repair system
consisting of tyre sealant and
compressor with separate tyre
pressure gauge is also standard.19-inch GT2 wheel
Less weight. More road contact.
Wheels.

· 49 · · 48 ·
The 911 GT2 |Chassis
The 911 GT2 is fitted with Porsche
Active Suspension Management
(PASM), an electronic damper
adjustment system. This active
damping system offers continuous
adjustment of individual damping
forces based on current road
conditions and driving style.
The driver can choose from two
basic setup modes: ‘Normal’ and
‘Sport’. ‘Normal’ mode is designed
for general road driving and wet
circuit use. ‘Sport’ mode enables
greater lateral acceleration and
increases traction on the race-
track.
In either mode, the system
responds to changing loads by
automatically applying the optimum
rate on each individual damper
from a range of predefined options.Various sensors are used to
monitor the movement of the body
during acceleration, braking and
cornering manoeuvres, as well as
on poor road surfaces. The PASM
control unit then evaluates this
data and modifies the damping
force on each individual wheel in
accordance with the selected
mode. The results are a reduction
in pitch and roll as well as con-
sistent road contact on all four
wheels.
If ‘Sport’ mode is selected using
the PASM button identified by a
damper symbol, the suspension is
set to a harder damper rating that
is specially designed for perform-
ance driving. If the quality of the
road surface falls below a certain
threshold, the system immediatelychanges to a softer rating within
the ‘Sport’ setup range. This
adjustment enhances occupant
comfort as well as traction and
grip. When the road surface
improves, PASM automatically
reverts to the original, harder
rating.
Rebound in ‘Sport’ mode –
damper piston with bypass
valve closedRebound in ‘Normal’ mode –
damper piston with bypass
valve open
Compression in ‘Normal’ mode –
damper piston with bypass
valve open
Compression in ‘Sport’ mode –
damper piston with bypass
valve closed
Redefining ‘normal’.
Porsche Active Suspension Management (PASM).

· 51 · · 50 ·The 911 GT2 |
Chassis
Some things never change,
including driver expectations of
a 911 GT2 : sports-oriented
performance, a direct response
and impressive power.
So Porsche Stability Management
(PSM) has been specially adaptedfor the 911 GT2. In addition to
ABS, the package includes two
automatic driver aids: stability
control (SC) and traction control
(TC).
Stability control (SC), which is
responsible for lateral dynamics,uses a range of sensors to moni-
tor the direction, speed, yaw
velocity (speed of rotation around
the vertical axis) and lateral
acceleration of the car. Using
this information, it is possible to
calculate the actual direction of
travel at any given moment. If thecar begins to oversteer or under-
steer, selective braking is applied
on individual wheels to restore con-
trol in critical driving scenarios.
Traction control (TC), with its
integrated ABD (automatic brake
differential), ASR (anti-slip regula-
tion) and EDC (engine drag-torque
control) functions, is responsible
for the longitudinal dynamics of the
car. Configured for sports-oriented
driving, traction control improveshandling under acceleration on
surfaces with inconsistent grip.
It also prevents the rear from
‘stepping out’ if a wheel loses
traction under full power. The
trigger threshold is relatively high,
which means it is rarely employed
in normal dry conditions.
A unique feature of PSM on
the 911 GT2 is that the control
interventions are delayed and
can be disabled completely in
two stages – for deliberate per-
formance handling.
Stage 1 disables the stability con-
trol (SC) via the ‘SC OFF’ switch in
the centre console. In ‘SC OFF’
mode, the control system does
not intervene if the car goes off-
course in the lateral direction,
which means the throttle can
be used to help steer the car.
Traction control (TC) is still active
in this mode.
Stage 2 disables the traction con-
trol as well via the separate
‘SC+TC OFF’ switch, giving the
driver full command of the vehi-
cle. Another unique feature is the fact that stability control
remains disabled in stages 1 and
2 even when the ABS is required
under braking. Specially develop-
ed for the 911 GT2, this revised
system strategy means the car
can also be enjoyed to maximum
effect on the racetrack.
The anti-lock braking system
(ABS 8.0) is integrated in PSM
and remains active, irrespective
of which settings have been
selected. ABS ensures a relatively
short braking distance and thus
enhanced safety.
It’s good to know who’s in control.
Porsche Stability Management (PSM).

· 53 · · 52 ·
The 911 GT2 |Chassis
The steering system is extremely
direct and provides detailed
feedback from the road. This
high level of precision is very
advantageous in both racing and
normal road use. Thanks to the
precise front-axle kinematics andthe variable steering ratio, the
car responds to every movement
of the wheel.
An important feature of the
steering system is the variable
ratio gearing. Around the straight-ahead position, the ratio
is less direct, enabling smoother
manoeuvres, such as during
motorway driving. There is less
risk of excessive steering inter-
vention destabilising the car at
high speed. Naturally, the systemprovides excellent feedback as
well as the usual agility. As the
wheel is turned harder, the ratio
becomes more
direct and the
steering more responsive. This
variability is
particularly beneficial
in low-speed hairpin bends. The
energy-absorbing steering column
is a key safety feature since, in
the event of a front-end impact, it
enables a deformation path of
100 mm.The intermediate steering shaft is
made from aluminium, while the
protective tube and steering lock
housing are die-cast magnesium.
The standard three-spoke GT2
steering wheel features manual
height and reach adjustment.
Used in conjunction with the seat
adjustment options, it enables
every driver to find the ideal seat-
ing position.
Maximum precision, however powerful the performance.
Steering.

Safety
Uncompromising performance
is nothing without safety.

· 57 · · 56 ·
The 911 GT2 |Safety
The 911 GT2 excels in every
respect, be it power, driving
dynamics or safety. Every aspect
of its lighting concept, braking
system, rigid body and ergonomic
interior is fine-tuned to its
performance and to the individual
driver. For example, the sportbucket seats (see page 72) with
folding backrest offer racecar-like
lateral support.
Lighting system.
The standard lighting system
on the 911 GT2 uses the latest
Bi-Xenon gas-discharge technology
to achieve a light quality similar
to daylight. The compact main
headlights provide a broad and
uniform swathe of light that
increases active safety in all
road scenarios and in long,
blind corners in particular.
The brightness of the gas-discharge
system featured in the Bi-Xenon
headlights is approximately double
that of conventional halogen units.
A headlight cleaning system is also
included as standard.
The horizontal indicators in
the outer front air intakes use
high-performance light-emitting
diodes (LEDs) to increase
brightness and visibility.
The high-level third brake light
at the base of the rear screen
is equipped with rapid-response
LEDs.Two additional lights on the inside
of each door offer added conveni-
ence and safety. The kerb light
(white) provides useful illumination
when stepping out of the car.
The safety light (red) warns traffic
approaching from the rear when
the door is open.
Bi-Xenon headlightsHigh-level third brake light
A must: absolute confidence in the safety of your car.
Active safety.

· 59 · · 58 ·
The 911 GT2 |Safety
The 911 GT2 is equipped as
standard with the Porsche
Ceramic Composite Brake (PCCB)
that has already demonstrated
its performance credentials on
the racetrack, for example, in the
vehicles of the Porsche Mobil 1
Supercup.only much harder than metal, it
is also more resistant to heat.
Even at high temperatures, the
thermal resistance of the PCCB
disc ensures exemplary dimen-
sional stability. The ceramic
material is totally resistant to
The large disc diameter (380 mm
front and 350 mm rear) adds sig-
nificantly to brake performance.
The ceramic discs are made from
a specially treated carbon-fibre
compound that is silicated in a
high-vacuum process at 1,700 ºC.
The material thus produced is notcorrosion and offers excellent
acoustic damping properties.
The pads are mounted in six-piston
monobloc aluminium fixed calipers
at the front, with four-piston units
at the rear. The resulting brake
forces are not only extremely
high, they are also exceptionally
consistent. The pedal response
is fast and precise with only
moderate input required.
PCCB enables shorter braking
distances in even the toughest
road and race conditions. Excel-
lent fade resistance ensures
greater balance when slowing
from racetrack speeds.
The key advantage of PCCB is
the total weight saving of approxi-
mately 50 % over comparable
metal discs. The mounting bells
on both front discs are made
from weight-saving aluminium. As
well as enhancing performance
and fuel economy, there is a major
reduction in both the unsprung
and rotating masses. This, of
course, improves comfort and
road-holding on uneven road
surfaces as well as general
handling and agility.
Please note that circuit racing,
trackday use and other forms of
performance driving can signifi-
cantly reduce the service life of
even the most durable pads and
discs. As with conventional high-
performance braking systems,
we recommend that all brake
components be professionally
inspected and replaced where
necessary after every track event.
Porsche Ceramic Composite Brake (PCCB)
When it comes to brake technology, we demand nothing but the best.
Porsche Ceramic Composite Brake (PCCB).

· 61 · · 60 ·
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The 911 GT2 |Safety
Bodyshell structure.
The 911 GT2 complies with all
statutory requirements worldwide
in respect of frontal, side,
diagonal and rear impact
protection.
The reinforced bodyshell contains
a highly resilient passenger
cell offering exceptional crash
protection. At the front of the
car, the cell is protected by a
patented system of longitudinal
and transverse members (1). In
the event of an accident, energy
is absorbed by three separate
load paths, one above the other,
which disperse the force of
impact and minimise deformation
of the passenger cell.
Additional features include an
extremely rigid bulkhead cross-
member (2) made from super
high-strength steel. This element is
designed to absorb impact forces
from the longitudinal members and
thus protect both front footwells. In
a minor collision, a system of easily
replaceable impact absorbers
(3) prevents costly damage to the
underlying bodyshell structure.
The reinforced doors (4) make
an increased contribution to
the overall rigidity of the car. An
additional load path (5) is used tochannel energy through the upper
part of the shell and thus further
protect the passenger cell.
In 1985, we began using super
high-strength steel elements
inside each door to increase side
impact protection. On the 911 GT2,
this integral reinforcement
is made
from tough yet lightweight
aluminium. By increasing the
proportion of aluminium alloys
and high-strength steel, we’ve
also improved the power-to-weight
ratio. In all, approximately 20 %
of the 911 GT2 is made from
aluminium.Another important but perhaps
less obvious safety feature is the
high-quality surface protection.
More than 30 years ago, we
became the first manufacturer in
the world to use a hot-dip gal-
vanised steel shell. This exacting
process is fundamental to thelegendary durability of our cars. It
also ensures a consistently high
standard of crash protection, even
after many years on the road.
Sheet steel
Tailored blanks
High-strength steel
Super high-strength steel
Aluminium
Intelligent crash technology.
Passive safety.

· 63 · · 62 ·
The 911 GT2 |Safety
Porsche Side Impact Protection
(POSIP).
The 911 GT2 is equipped as
standard with the latest generation
of Porsche Side Impact Protection
(POSIP). It features two additional
airbags for each front seat: a
head airbag located in each door
and a thorax airbag in the folding
Porsche Side Impact Protection (POSIP)
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 arrange-
ment allows faster and more
accurate crash evaluation and
thus better airbag deployment.Airbags.
The 911 GT2 has a specially
developed airbag technology
with a total of six airbags. The
full-size front airbags have a two-
stage inflation function which
deploys each airbag separately in
accordance with the force and
nature of the impact (e.g., frontal
or diagonal) before inflating each
airbag accordingly. In a low-speed
crash, the airbag is only partially
inflated, thereby minimising
discomfort to the occupants.
backrest on each of the standard
sport bucket seats (see page 72).
As well as offering exceptional
support, the sport bucket seat
provides a much higher level of
safety than conventional bucket
seat designs.
The thorax and head airbags each
have a volume of approximatelyeight litres, providing high protec-
tion in the event of a side impact.
Another important element of
POSIP is the side impact protection
with door reinforcement.
Other safety features of the
911 GT2 are head restraints that
are an integral part of each seat,
an energy-absorbing steering column, three-point seat belts
with height adjustment, seat-belt
pre-tensioners and force limiters,
energy-absorbing elements in the
dashboard, and flame-retardant
materials throughout the interior.