2008 PORSCHE CAYENNE engine

Chassis
Precision in design.
Precision on the road.
location is more accurate and
agility is enhanced, with minimal
disturbance on uneven surfaces.
The subframe is secured on
rubber mountings that minimise
road noise and thus enhance
the engine acoustics.
Made from lightweight high-
strength steel, the front
suspension subframe is specially
constructed to increase the
rigidity of the car.
The resulting benefits include
greater stability, greater comfort
and even greater active and
passive safety. In the event
of an accident, the subframe
deforms in a predefined manner
to provide additional protection
for the passenger compartment.
Front axle.
A powerful and responsive engine
requires an equally responsive
chassis.
The front axle on all fourCayenne
models features subframe-mounted
double wishbone
suspension with
high-mounted upper arms. By
raising the top
wishbones, wheel
Rear axle.
A balanced chassis is essential
on any car and one of the major
challenges in vehicle design.
On all four Cayenne models, we
solved this problem using multi-
link rear suspension. Ideal for
performance road and track
use, it also copes well with the
extremely high towing and
carrying loads that are possible
with each Cayenne.
The lower suspension links and
track rods have a special sheet
steel construction offering greater
strength. The upper links are
located high in the wheel arches
and can therefore be made from
lightweight forged aluminium.
The suspension struts are angled
to allow longer suspension travel
and create a deeper and wider
cargo area. As well as providing
additional space, the car is easier
to load. A key advantage of the
rear axle design is its ability to
minimise dive and squat under
acceleration and braking. It also
uses active toe-angle control to
improve mid-corner stability and
compensate for sudden load
transfer, e.g., lift-off oversteer.
In short: a chassis you would
expect from Porsche. Specially
developed in Weissach.
Front axle (Cayenne Turbo) Rear axle (Cayenne Turbo)
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Chassis
Active damping adjustment for optimum performance and comfort.
Porsche Active Suspension Management (PASM).
Both systems are optional on
the Cayenne and Cayenne S. The
Cayenne GTS has an exclusive
combination of PASM and high-
performance steel-sprung suspen-
sion (ride height lowered by 24 mm).
During performance driving or
heavy off-road use, there is a
greater tendency for the body
to roll. PASM prevents this from
happening, thereby improving
stability and occupant comfort.
PASM has three setup modes:
‘Comfort’, ‘Normal’ and ‘Sport’.
In all three cases, the system
uses a series of sensors to
monitor the movement of the
body, e.g., under acceleration and
braking or on poor road surfaces.
It also gathers data on lateral
acceleration, steering angle, brake
pressure and engine torque. The
PASM control unit then evaluates
this information and modifies the
damping forces in accordance
with the selected mode.
PASM remains active at
all times, adapting to the
changing conditions.
If the road surface deteriorates
while travelling in ‘Sport’ mode,
for instance, the system
immediately changes to a softer
rating, thereby improving road
contact. When the road surface
improves, PASM automatically
reverts to the original, harder
rating. This not only increases
stability and safety, it also
enhances comfort.
PASM is an electronic damping
control system. It offers continuous
adjustment of individual damping
forces based on current road
conditions and driving style. PASM
is standard on the Cayenne Turbo
in conjunction with air suspension.
· 77 · · 76 ·PASM control with ‘Comfort’, ’Normal’ and ‘Sport’ options

Off road
Porsche Hill Control (PHC) uses
engine braking to enable steady
descent on otherwise hazardous
gradients at speeds of up
to 20 km / h (12.5 mph). If one
or more wheels begin to lose
traction, PHC compensates by
applying increased engine braking
on those that retain contact withthe ground. With no need to
adjust braking, the driver can
concentrate fully on steering
the car.
With steel-sprung suspension,
the maximum wading depth is
500 mm.* With the optional air
suspension (standard on the
Cayenne Turbo), the car is secure
to a depth of 555 mm.**
On extremely uneven terrain,
you can smooth your path with
the optional Porsche Dynamic
Chassis Control (PDCC). Featuring
active anti-roll bars, the PDCC
off-road mode is automatically
enabled whenever ‘low-range’
mode is selected. With greater
articulation of each wheel, there
is less unwanted body-roll and
occupant comfort is improved.
PDCC in on-road mode: reduced wheel articulation
PDCC in off-road mode: increased wheel articulation
**Cayenne GTS: 476 mm.** Cayenne GTS with air suspension: 535 mm.
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Off road
Applying power with sensitivity, protecting with strength.
Off-road Technology package.
The rear differential enables
optimum distribution of engine
torque in difficult off-road terrain.
A fully automated part of the
all-wheel system, its primary
function is to optimise traction.
If one of the rear wheels begins
to lose grip, the differential varies
the torque transmitted through
each drive shaft, thereby restoring
traction. Available as a factory-fitted
option on all Cayenne models, the
Off-road Technology package*
incorporates an electronically
variable and lockable rear
differential as part of the standard
all-wheel drive system. Other
features include high-strength
rock-rails with integrated skid
plates, a reinforced engine-bay
guard, enhanced protection for
the fuel tank and rear axle, and
a second towing lug.In low-range mode, the rear
differential can be manually
locked using the main off-road
control on the centre console.
In this state, both rear wheels
receive the same amount of
torque.
For additional off-road protection,
optional wheel-arch extensions
(black finish) and running boards*
with integrated skid plates are
available.
* Not available for the Cayenne GTS.
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piston units at the rear. The
resulting brake forces are not
only high, they are also extremely
Porsche Ceramic Composite Brake (PCCB).
Porsche Ceramic Composite Brake (PCCB),
front disc diameter: 410 mm
The pads are mounted in six-
piston monobloc aluminium fixed
calipers at the front, with four-
Safety
As an optional alternative, the
Cayenne S, Cayenne GTS and
Cayenne Turbo can all be
equipped with the race-proven
Porsche Ceramic Composite
Brake (PCCB)*.
The large disc diameter (410 mm
front and 370 mm rear) adds
significantly to brake performance.
The discs are made from a
specially treated carbon-fibre
compound that is silicated in a
high-vacuum process at 1,700 ºC.
The resulting material is not only
much harder than cast iron, it
is also more resistant to heat.
Even at high temperatures, the
thermal resistance of the PCCB
disc ensures excellent dimensional
stability. The ceramic material is
totally resistant to corrosion and
offers excellent acoustic damping
properties.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.
Excellent fade resistance ensures
greater balance when slowing
from high speed.
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The Porsche Ceramic Composite
Brake (PCCB) is a visible
acknowledgement of Porsche race
engineering. The key advantage
is a total weight saving of
approximately 50 % compared
with equivalent cast-iron discs.
As well as enhancing performance,
the unsprung and rotating masses
are lightened. The results: greater
comfort and road-holding
on uneven road surfaces plus
better handling and agility.
* Compatible with 20-inch wheel diameter or greater as well as 19-inch collapsible spare wheel.

Oversteer with PSM
Understeer without PSM
Car steers
off line Car steers
off line PSM corrects
line and
stabilises car
PSM corrects
line and
stabilises car
Understeer with PSM Oversteer without PSM
All Cayenne models are
equipped with Porsche Stability
Management (PSM) as standard.
This electronic control system
uses a range of functions –
including anti-lock braking (ABS) –
to help stabilise the vehicle
(and trailer, if fitted) in hazardous
road scenarios. Throughout each
journey, PSM 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. The system then calculates
the actual direction of travel. If
the car begins to oversteer or
understeer, PSM applies selective
braking on individual wheels to
restore stability. If necessary,
PSM can also intervene in the
engine management system to
temporarily modify the amount
of drive to the wheels.PSM has two additional functions
that help reduce braking distances.
If the throttle pedal is released
suddenly, PSM automatically
readies the braking system. The
pressure in the brake lines is
marginally increased, bringing
each of the pads into light contact
with the corresponding disc. If the
driver goes on to apply the brakes,
the calipers respond more quickly.
In an emergency stop – i.e., when
the pressure on the brake pedal
exceeds a certain threshold –
the brake assist function uses
the PSM hydraulics to apply
maximum braking force at all
four wheels.
PSM makes a significant contribu-
tion to car and trailer safety –
within the laws of physics. It
compensates for load transfer
caused by throttle and brake
inputs up to the maximum degree
of lateral acceleration. It also
enhances the car’s driving dynam-
ics and directional stability when
accelerating on variable road
surfaces. PSM can also intervene
through the locking centre and
axle differentials as part of
Porsche Traction Management
(PTM).
Other features include a
special control strategy in
the PSM-integrated ABS for braking on loose surfaces such
as gravel or snow. By briefly
locking the wheels, a wedge is
formed ahead of each tyre which
provides additional purchase
to help slow the car.
For a more active driving experi-
ence, PSM can also be disabled.
For safety reasons, it remains
active in the background, ready
to intervene in critical scenarios.
Expecting the best means preparing for the worst.
Porsche Stability Management (PSM).
Safety
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The secret of performance?
Efficiency.
OBD II on-board diagnostics. The
key components, however, are the
primary and secondary catalytic
converters on the twin exhaust
tracts. Each catalyst has a rapid
warm-up cycle so emissions are
which the engine management
system uses to establish the
optimum air/fuel mix and monitor
the efficiency of the catalytic
converters.
standard as well as LEV2 – LEV
(Cayenne and Cayenne Turbo)
and LEV2 – ULEV (Cayenne S
and Cayenne GTS) regulations
in the United States. Whatever
the class, every Porsche
combines high performance
Exhaust emissions.
The Cayenne models are all
equipped with the very latest
emissions technologies. As a
result, they comply with both the
stringent EU4 exhaust emissions
with only moderate emissions.
On the Cayenne models, this is
achieved using an advanced
engine concept featuring direct
fuel injection, VarioCam Plus
(V8 engines) or variable valve
timing (V6 Cayenne) as well asreduced sooner when starting
from cold.
Another important feature is
the use of twin oxygen-sensor
circuits. Each bank of cylinders
has a separate control system
Environment
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Environment
Fuel system.
We have also applied the highest
engineering standards to protect
the environment from fuel
evaporation. The non-return
fuel supply system provides a
considerable reduction in vapour
emissions. The fuel lines are
partly constructed from steel,
while those carrying vapour are
made from multi-layer plastics.
A large active-carbon filter and
multi-layer plastic fuel tank help
reduce evaporation even more.
A leak detection pump is also
included to monitor the integrity
of the fuel tank system.
Acoustics.
Think of a Porsche and what
do you hear? One of the most
distinctive sounds on the road.
A sound created not just by the
engine, but also by the absence
of unwanted noise. To minimise
Fuel economy.
At Porsche, we’re using innovative
technologies to increase perform-
ance while enhancing fuel economy.
With direct fuel injection (DFI),
we’ve made our engines more
efficient in terms of both output
and consumption. DFI is combined
with VarioCam Plus in the V8 engines
and variable valve timing in the
Cayenne V6. As well as improving
performance and economy, both
of these systems help to minimise
engine emissions. The low-drag
exterior on each Cayenne model
further improves efficiency.
Fuel.
All Porsche models are already
compatible with a fuel ethanol
content of up to 10 %. Ethanol
has a positive impact on the carbon
dioxide balance since the plants
grown for its production absorb
carbon dioxide from the atmosphere.
‘play’ between engine components
under all load conditions, we’ve
used stronger, lighter and more
temperature-resistant materials.
This reduces mechanical noise
and eliminates the need for engine
encapsulation. Large-volume
silencers and air intake manifolds
also help to minimise noise –
throughout the life of the car.
Tyre noise has been drastically
reduced in collaboration with
our official tyre partners. Wind
noise levels have also been
lowered thanks to aerodynamic
refinements.
All that remains is the Porsche
sound – as legendary as ever.
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