2011 PORSCHE CAYENNE fuel pump

consistently within a specific
temperature range. The engines
in the Cayenne models are
therefore designed for ef ficient
cooling.
In order to reduce the frictional
losses that occur during warm -up,
all Cayenne models feature com-
prehensive thermal management.
Using intelligent control, it
activates the dif ferent cooling
circuits individually and on de-
mand, thereby ensuring that the
optimum operating temperature
for the engine and transmission
is reached more quickly. This
minimises friction – and keeps
fuel consumption and CO
2 emis-
sions low.
The V8 engines have an enhanced
coolant management system
offering effective temperature
control throughout the engine.
While 20 % of coolant flows longi-
tudinally through the crankcase,
the remaining 80 % serves the
cylinder heads using the proven
cross-flow principle (from hot to
cold).
On all Cayenne models, the piston
heads are cooled using oil-spray
jets integrated within the main
lubrication system.
The entire cooling system is
designed for prolonged heav y-
dut y use, e.g. of f-road driving
or heav y towing and carrying
applications.Lubrication.
The V8 engines use dry-sump
lubrication to ensure a consistent
supply of oil in all load conditions,
especially in of f-road terrain.
The oil reservoir is located inside
the engine. This saves on space
and reduces weight.
Oil is circulated around the V8
engines using a demand- driven
pump. This has been designed
for the toughest driving scenarios
on and off road, including per-
formance driving and extreme
gradients. The V6 engines have a wet-sump
lubrication system.
Ensuring a
reliable supply of oil, no mat ter
how challenging the driving
conditions.
Direct fuel injection on the
diesel engine (common-rail
injection system).
On the Cayenne Diesel, direct
fuel injection comes courtesy of
a common -rail injection system.
The injection pressure is now up
to 2,000 bar, ensuring optimum
distribution of the air/fuel mixture
– for greater performance. The
piezoelectric injectors provide
flexible injection rate
adjustment,
using exactly metered quantities
of fuel, with multiple injections
for each power stroke to deliver
smooth combustion.
Cooling systems.
A high -performance engine can
only maintain its maximum
capabilit y over a long service life
if all components are operating
Direct fuel injection (DFI).
DFI injects fuel directly into the
combustion chamber at up to
120 bar with millisecond precision
using electromagnetic injectors.
The injector position and spray
geometry have been carefully
designed to improve output,
torque, fuel economy and emis-
sions. The swirling of the fuel as
it enters each chamber increases
the mixing of air and fuel, thereby
enhancing combustion. By form-
ing the air/fuel mixture directly
in the combustion chamber, DFI
contributes to engine cooling.
As a result, it was possible to in-
crease the compression ratio and
therefore power and efficiency.

Compression with precision.
Essential for getting right to the point.
38 · Drive systems and chassis | Engine technology

An electr ic pump is used to
m a i ntain the r equired p re ssu re
of the t ransmis sion fluid , e.g.
to t ransmit high l evels of torque
at lower engine speeds.
The s tanda rd sports steering
wheel in conjunction with
T i p t r o nic S h as t wo e rgonom ic
switch es for manual gear
c h a n g es. One p re ss forwa rd with
the thumb and Tiptronic S shif ts
up. One pull backwa rds with
the in dex finger and Tiptronic S
shif ts down. Either the right or
l eft-hand switch can be used.
tackling a
sce nts and towing loads
in off-road ter rain. Top speed is
reached in 6th gear (in 7th gear
on the Cayenne Diesel). The
remaining
upper gea rs a re used
to lower the r evs at high speed ,
the reby enhancing fuel economy
and occupa nt comfo rt. On the motorway in particular , driving at
low r evs will s ignifica ntly r educe
the noise l evel insid e the veh ic le.
In automatic mode, the driver
can influence gea rshifts on the
Tiptron ic S using the throt t le and
b rak es alone.
Tiptronic S auto -
mat ically adapts the gea rshif t
points for performance driving –
equally , if a mo re d efen sive driv-
ing s tyle is d etec ted , the sy stem
se lects a gea rshift poi nt that
o f f e rs maximum fuel economy.
Un der heav y b raking , Tiptron ic S
shifts down to maxi mise engine
b raking. Natu
rally , you can also change
gear u sing the gear se lector lever
on the ce ntr e cons ole.
Standard on the Cayenne Diesel,
Cayenne S, Cayenne S Hybrid
and Cayenne Turbo. Optional
for the Cayenne.
Eight-speed Tiptronic S.
The out standing featu re of the
eight-speed Tiptron ic S is a
pa rticularly wi de ratio sp read.
Fi rs t gear is designed for optimum
acceleration when pulling away
and g rea ter performance when
Six-speed manual gearbox.
The six-speed manual gearbox
on the Cayenne has been specifi-
cally adapted for the demands
of high-performance use. The
gear lever throw is short and pre-
cise, and each of the six ratios
has been selected for optimum
progression through the gears. As
the centre console rises to meet
the dashboard, the gear lever is
close to hand – for an even more
engaging drive.
The standard upshif t display in
the instrument cluster helps
to reduce fuel consumption still
further.
Eight-speed Tiptronic S is also
available as an option on the
Cayenne in conjunction with the
auto start /stop function.
Standard on the Cayenne.
Precision control.
Whatever your choice of terrain.
Transmission.
Tiptronic S gear selector
42 · Drive systems and chassis | Transmission Drive systems and chassis | Transmission · 43

high -mounted upper arms are
in aluminium. This axle design
ensures accurate wheel location,
greater agilit y and minimal inter-
ference on uneven surfaces.
The subframe is secured on large
rubber mountings that reduce
road noise to a minimum. It is
also specially constructed to
increase stabilit y. For enhanced comfort and even greater active
and passive safet y. In the event
of an impact, the subframe
deforms in a predefined manner.

Rear axle.
The rear axle features multi-link
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 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 also
easier to load.
The rear axle design minimises
dive and squat under acceleration
and braking. It also improves mid-
corner stabilit y and compensates
for sudden load transfer. In short:
it enables a more relaxed way
of driving. Examples of intelligent
light weight construction on the
rear axle include hollow drive
shafts.
Steering.
The steering system has been
completely revised and adapted
for a more immediate response
and greater driving dynamics.
Around the straight-ahead pos-
ition, in particular, the ratio is
now more direct. With the variable
steering ratio and special valve
set tings on the power-steering
system, optimum manoeuvrabilit y
is ensured. The turning circle
of the Cayenne models is just
11.9 metres.
The steering column itself
consists of multiple collapsing
sections linked by t wo universal
joints and a special deformation
element provides additional safet y
in the event of a front impact. Electro -hydraulic power steering
is used for the first time on the
Cayenne S Hybrid. The demand-
driven pump only provides
assistance to the steering as
and when required, thereby
contributing to overall efficiency.
Servotronic.
Servotronic is a speed-sensitive
power-steering system.
At higher speeds, the steering
becomes firmer, inputs are more
precise and driver comfort is
enhanced. At lower speeds, it
enables easy manoeuvrability
and parking.
Standard on the Cayenne S
Hybrid. Optional for all other
Cayenne models.
Front axle.
The chassis on the Cayenne
models offers a direct response –
for a more rewarding driving
experience.
The wishbones on the subf rame-
mounted front suspension with
Weight reduction.
The axle concept on the Cayenne
models features con sistent light-
weight construction. The results:
enhanced driving dynamics, lower
fuel consumption and optimum
occupant comfort.
Shedding weight.
Adding agility, economy and comfort.
Drive systems and chassis | Chassis · 55