2008 PORSCHE CAYENNE fuel pump

1. Air intake system
2. High-pressure pump
3. VarioCam Plus
(rotary-vane adjuster)
4. Duplex timing chain
5. High-pressure fuel rail
6. Injector (obscured)
7.
VarioCam Plus (switchable
tappet with hydraulic valve
clearance adjustment)
8. Inlet camshaft
9. Exhaust camshaft
10. Valve
11. Piston
12. Spark plug
13. Exhaust manifold
14. Turbocharger
15. Oil filter
16. Oil /coolant heat exchanger
17.
Air-conditioning compressor
18. Oil pump pick-up pipe
19. Water pump (obscured)
20. Ancillary drive belt
21. Throttle-valve tract
(electronic throttle)
Cayenne Turbo engine
1011
12
13
14
15
16
17
18
19
20
21
1
2
3
4
56
78
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Drive

Power is the product of efficiency.
Lightweight alloy engine construction.
‘Less is more’ – less weight, more
performance – is a key principle of
Porsche design.
The V8 Cayenne engines have
a ‘closed-deck’ aluminium
crankcase and lightweight
aluminium bedplate. The cylinder
block and its associated coolant
channels are therefore a fully
enclosed system. This not only
reduces the weight of the engine,
it also improves its dimensional
stability. Since the engine is
stronger, it also has a longer
service life.
Other major lightweight compon-
ents include cast aluminium
pistons and aluminium cylinder
heads. On the Cayenne Turbo, the
pistons are forged to compensate
for the higher loads.
The Cayenne V6 has a cast-iron
crankcase and one-piece cylinderheads in die-cast aluminium. This
combination produces high power
output while reducing the weight
of the engine.
Drive
Lightweight construction used on the V8 engines
Consistent performance and a longer service life.
Engine cooling system.
Each engine remains within its
optimum temperature range at
all times. Clearances throughout
the engine are extremely small,
thereby reducing wear. The entire
cooling system is designed for
prolonged
heavy-duty use, e.g.,
off-road driving or heavy towing
and carrying applications.
Emissions, noise and fuel
consumption remain low, while
power and torque are improved.
Lubrication.
The V8 engines use dry-sump
lubrication to ensure a consistent
supply of oil in all load conditions.
The oil reservoir is located inside
the engine. As well as saving
space and reducing weight, the oil
is always there where it’s needed.
Oil is circulated around the
V8 engines using a demand-driven
pump and two-stage scavenging
system, providing optimum
delivery in even the toughest
scenarios.
The V6 engine has a wet-sump
lubrication system that is
also designed for challenging
conditions, e.g., performance
road driving or extreme off-road
gradients.
A high-performance engine can
only maintain its optimum capability
over a long service life if all com-
ponents are operating consistently
within a specific temperature
range.
The V8 engines have an optimised
coolant management system offering
effective temperature control
throughout the engine. While 20 %
of coolant flows longitudinally
through the crankcase, 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 in the main lubrica-
tion system.
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Controlling fuel delivery for optimum combustion.
Direct fuel injection (DFI).
Drive
designed to improve power, torque
and emissions. The swirling of the
injected fuel creates a homogenous
air/fuel mix, thereby enhancing
combustion.
At engine speeds up to 3,500 rpm,
a double injection process is used.
Here, the required fuel volume
is delivered in two successive
injections per working stroke. The
results are faster catalyst warm-up
and increased torque in the upper
load range. All four Cayenne engines feature
direct fuel injection.
As the name suggests, fuel is
injected directly into each
combustion chamber using electro-
magnetic injectors offering
extremely high precision in
terms of both timing and volume.
A high-pressure pump provides
the necessary pressure of up to
120 bar.
The injector position and spray
geometry have been carefully
From road to racetrack. At the push of a button.
‘Sport’ button.
Throttle response in ‘Sport’ mode
Throttle response
in ‘Normal’ mode
Both sets of characteristicsare dependent on engine
speed.
Pedal travel (%)
(%) Torque
(as percentage of maximum)
All Cayenne models have a
standard ‘Sport’ function with
a choice of comfort-oriented
(‘Normal’) or high-performance
(‘Sport’) setup.
When ‘Sport’ mode is enabled
using a button on the centre
console, the engine management
system selects a more ‘aggressive’
map for the electronic throttle.
The pedal response is quicker
and the engine more dynamic
and direct. On vehicles with
Tiptronic S, upshifts are performed
later, downshifts earlier. The
chassis control systems PASM
and PDCC (if present) are also
set to ‘Sport’ mode. Cars with
air suspension are lowered to
Low Level I, creating a firmer
ride, more positive turn-in and
better contact with the road.
The ‘Sport’ sound mode on the
sports exhaust system (standard
on Cayenne GTS; optional on
Cayenne S with Tiptronic S) is
also enabled when ‘Sport’ mode
is selected.
‘Sport’ button on centre console Comparison of electronic throttle map in ‘Normal’ and ‘Sport’ mode
By mixing the fuel and air directly
in the combustion chamber, DFI
contributes to engine cooling.
As a result, it was possible
to increase the compression
ratio and therefore output and
efficiency.
The engine management system
regulates the injection process
based on changing output require-
ments. Oxygen sensor circuits
are used to monitor emissions
and minimize impact on the
environment (see page 60). This
also reduces ownership costs.
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· 58 · · 57 · · 56 ·
Used to regulate /control Input data Used to regulate /control
Engine management system
(MED 9.1)
Engine load
Throttle-valve angle
Oxygen sensor signals
Engine speed (from crankshaft)
Inlet camshaft phase angle
Knock sensor signals
Vehicle speed
Air-conditioning settings
Throttle pedal position
Temperatures
– Coolant
– Intake air
– Engine oil
– Ambient air
Zündung
Direct fuel injection (DFI)
Idling via throttle valve and ignition
Heating elements in oxygen sensors
Demand-controlled fuel pump
Fuel-tank venting
CAN interface to PSM control unit, transmission control unit, engine immobiliser, instrument cluster,
air-conditioning control unit, ‘Sport’ button, on-board diagnostics, etc.
Input data
Camshaft phase angle
Engine fan
Starter
Fuel pressure
Throttle valve
Intake manifold resonance valve
Engine management functions in the Cayenne S, Cayenne GTS and Cayenne Turbo. Engine management functions in the Cayenne.
Drive
Maximum freedom requires total control.
Electronic engine management.
The electronic engine management
system provides coordinated
regulation of all engine functions
and associated systems in all
operating conditions.
The basic principle of engine
management is simple. Throughout
each journey, the system monitors
a range of input data and compares
it with corresponding sets of
reference values (‘maps’). Key
engine functions, such as ignition
and fuel injection, can be seamlessly
and automatically adjusted. The
results: optimum fuel economy and
lower emissions as well as greater
power and torque.One of the most important systems
controlled by engine management
is the electronic throttle, a
prerequisitefor Porsche Stability
Management
(PSM). Other major
functions include on-board diagnos-
tics and cylinder-specific knock
control featuring automatic compen-
sation for changes in fuel quality.
On the Cayenne, Cayenne S
and Cayenne GTS, the engine
management system controls
the variable-tract intake manifold.
On the Cayenne Turbo, it regulates
the turbo boost pressure.
Fuel pressure
Oil pressure
Engine management system
(EMS SDI 4.1)
Throttle-valve angle
Oxygen sensor signals
Engine speed (from crankshaft)
Inlet camshaft phase angle
Knock sensor signals
Vehicle speed
Air-conditioning settings
Throttle pedal position
Temperatures
– Coolant
– Intake air
– Engine oil
– Ambient air
Ignition
Direct fuel injection (DFI)
Idling via throttle valve and ignition
Heating elements in oxygen sensors
Demand-controlled fuel pump
Fuel-tank venting
CAN interface to PSM control unit, transmission control unit, engine immobiliser, instrument cluster,
air-conditioning control unit, ‘Sport’ button, on-board diagnostics, etc.
Valve lift (VarioCam Plus)
Engine fan
Starter
Fuel pressure
Throttle valve
Intake manifold resonance valve
(Cayenne S/Cayenne GTS)
Fuel pressure
Oil pressure
Wastegate frequency valve
(Cayenne Turbo only)
Bypass valves (Cayenne Turbo only)
Camshaft phase angle
Oil pressure
Engine load
Ignition
Cylinder-specific knock control
Cylinder-specific knock control

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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