2008 PORSCHE 911 GT2 ignition

1
2
3
45
22
21
1920
9
6
24
25
16
11
12
14
13
23
15
17
7
8
10
18
· 23 · · 22 ·The 911 GT2 |
Drive
1. Oil scavenge pump
2. Oil-pressure pump (obscured)
3. Engine oil reservoir
(dry-sump lubrication)
4. Camshaft adjuster (VarioCam Plus)
5. Intake camshaft
6. Tappets with hydraulic valve
clearance adjustment
7. Valve springs
8. Valves
9. Nikasil-coated cylinder bore
10. Forged aluminium piston
11. Forged connecting rod
12. Crankshaft
13. Camshaft drive chain
14. Camshaft drive chain
tensioner with guide rail
15. Single-spark ignition coil
16. Spark plug
17. Exhaust-gas turbocharger with
Variable Turbine Geometry (VTG)
18. Main silencer (titanium)
19. Tailpipe (titanium)
20. Catalytic converter
21. Pressure pipe
22. Throttle valve (electronically
actuated)
23. Expansion intake manifold
24. Air filter
25. Fluid reservoir for power-steering
system

· 33 · · 32 ·The 911 GT2 |
Drive
Unfortunately, compression not
only increases air volume, it also
increases air temperature and this
has a negative effect on ignition.
Our new expansion manifold simply
turns that principle around. The
internal geometry is radically
different from that on a resonance
intake system. Key modifications
include a longer distributor pipe,
with a smaller diameter, and
shorter intake pipes.Expansion intake manifold.
More power than a 911 Turbo -–
from the same engine? Not easy.
But feasible, which is why it
required yet another spectacular
innovation from Porsche.
The 911 GT2 has an innovative
expansion intake system with a
unique working principle which
overturns the methods previously
used. Our ‘expansion’ intake
mani-
fold is a radical new
developmentthat is the polar opposite of
the resonance principle used
on conventional turbocharged
engines.
A resonance manifold increases
engine output by forcing add-
itional air into the combustion
chambers. To do this, the mani-
fold is designed in such a way
that the air – which vibrates
due to the action of the valves –
is in a compression phase as it
passes through the inlet ports.As a result, the air is in the
expansion phase as it enters the
combustion chambers. Since
expansion always cools, the
air/fuel temperature is lower and
ignition is significantly improved –
thereby increasing performance.
Of course, the amount of air
that enters the engine under
expansion is less than it would
be under compression. To
compensate for this, we’ve simply
increased the boost pressurefrom the turbochargers by
approximately 0.2 bar. The result-
ing increase in temperature –
again through compression – is
immediately offset by the uprated
intercoolers.
Instead of hot compressed
air entering the combustion
chambers, we now have cooler
air generating more power and
torque. As a consequence,
there is a major improvement in
engine efficiency and thereforelower fuel consumption even under
heavy loads and at high rpm.
A simple solution, but then that’s
often the way when you take
a new approach to old ideas.
Expansion intake manifold

· 34 ·· 35 ·
The 911 GT2 |Drive
Exhaust system.
The rear silencer and tailpipes
of the 911 GT2 are made from
ultra-lightweight titanium to re-
duce the weight on the rear axle,
and improve driving dynamics.
The exhaust leaves the engine
through high-performance
manifolds into separate tracts
for each of the two banks of
cylinders. Twin three-way catalytic
converters clean the two streams
before they converge in the main
silencer unit. The twin
titaniumtailpipes are fully integrated
within
the rear apron moulding. Large-
diameter tubes reduce back-
pressure
on the engine,thereby
increasing performance. The
catalytic
converters are close
to the engine,
enabling faster
warm-up and therefore improving
efficiency. When starting from
cold, the process is assisted by a
secondary air injection system.
A system of ‘Lambda’ or oxygen
sensors in each of the exhausts
provides continuous monitoring of engine efficiency. Data supplied
by one pair of sensors enables
the engine management system
to perform separate adjustment
of the air/fuel mix for each bank
of cylinders. A further pair of sen-
sors*, one on each tract, is used
to monitor the efficiency of the
respective catalytic converter. This
facility enables much more accu-
rate control of potentially harmful
emissions.
The exhaust system on the
911 GT2 produces a warm,
deep and bass-rich sound –
even when the engine is idling.
Fuel system.
Fuel is supplied to each of the six
cylinders using a sequential fuel
injection system. The timing of
each injection and the volume
supplied to each bank of cylinders
are controlled by the engine
management system. Adjustmentsare based on a range of variables,
including throttle position, engine
speed, boost pressure, coolant
temperature and exhaust gas com-
position. The results are optimised
combustion and fuel consumption.
A hot-film air mass sensor moni-
tors the volume and density of the
incoming air to ensure the best
possible air/fuel mix, regardless
of weather and altitude.
Ignition system.
The 911 GT2 features static
high-voltage ignition technology.
Separate coils on each of the
plugs with platinum electrodes
ensure perfect ignition every
time. The role of distributor is
performed by the engine manage-
ment system, which controls the
individual spark plugs directly,
for optimum performance and
minimum fuel consumption.
* Not in markets with leaded fuel.Exhaust system

· 37 · · 36 ·
The 911 GT2 |Drive
benefits, such as optimum econ-
omy, emissions and performance
in all driving scenarios.
One of the most important tasks
performed by the engine manage-
ment system is cylinder-specific
knock control. By preventing pre-
ignition at high engine speeds
and loads, this function can avert
costly damage to the pistons and
cylinders. Since temperatures
tend to vary across the engine,
each cylinder is monitoredseparately. If a risk is detected,
the individual ignition timing is
adjusted.
The on-board diagnostics system,
designed to European standard,
quickly detects any faults in the
exhaust and fuel system and
displays them during driving
via the car’s instruments. The
benefits include active prevention
of harmful emissions as well
as consistent rates of fuel con-
sumption.Input data Used to regulate /control
Digital engine electronics
(ME7.8.1 control unit)
Engine load
Pressure upstream from throttle
Throttle-valve angle
Engine speed (from crankshaft)
Inlet camshaft phase angle
Throttle-pedal position
Oxygen sensor signals
Knock sensor signals
Ignition
Fuel injection
Throttle valve
Heating elements in oxygen sensors
Fuel pump
Fuel-tank venting
CAN interface to transmissionMoment interface to Porsche
Stability Management (PSM)
VarioCam Plus
– camshaft phase angle
– valve lift control
Electronic controller for
Variable Turbine Geometry (VTG)
Recirculation valve
Secondary air injection
Engine-bay fan
Starter
On-board diagnostics
Air-conditioning compressor
Interface to instrument cluster
Radiator fans (front control unit via CAN)
Vehicle speed
Air-conditioning settings
Engine immobiliser status
Clutch pedal switch
Ambient air pressure
Temperatures
– coolant
– air upstream from throttle
– engine oil
– air in engine compartment
– ambient air
Exhaust-gas temperature
Engine management system.
The Motronic ME7.8.1 engine
management system facilitates
optimum performance at all
times. This high-precision ECU
controls all engine-related func-
tions and assemblies (see
dia-
gram), such as Variable Turbine
Geometry, VarioCam Plus and
the electronic throttle, one of the
key prerequisites for the standard
Porsche Stability Management
(PSM). This produces various

· 75 · · 74 ·
The 911 GT2 |Comfort
‘Welcome Home’ lighting.
This standard lighting function
provides comfort and safety at the
push of a button. The low-beam
headlights are automatically
illuminated when the car is locked
or unlocked using the key remote.
The lights remain illuminated for
a predefined period, lighting your
way to or from the car. This delay
is user-adjustable via Porsche
Communication Management
(PCM) on vehicles with the optional
Sport Chrono Package Plus.
ParkAssist.
This optional parking aid is auto-
matically enabled whenever you
select reverse gear. Move too
close to a stationary object and a
warning signal is emitted. Continue
to reverse and the tone increases
in frequency. The distance is
measured by ultrasonic sensors
which are neatly concealed in the
rear bumper.
Cruise control.
This convenient option has an
effective range of 30 – 240 km / h
(19 – 149 mph). The system is
operated using a switch in a
separate control stalk on the
steering column and can even
be used in first gear.
HomeLink®
(garage door opener).
This optional garage door opener
is freely programmable and inte-
grated within the cockpit. It offers
remote control for up to three
garage, gate, home lighting and/or
alarm systems and is compatiblewith almost all garage and exterior-
door systems.
Automatically dimming interior
and exterior mirrors.
An auto-dimming function is
available as an option for the
911 GT2 for interior and exterior
mirrors. The package also includes
an integrated rain sensor for the
front wiper system.
Luggage compartment.
The volume of the luggage
compartment in the 911 GT2 is
105 litres. The entire compartment
is lined with high-quality, scratch-
resistant materials. The bulkhead
panelling conceals the amplifier
of the optional BOSE
®Surround
Sound System and the DVD drive
for the optional navigation module.
The additional 205-litre rear load-
space inside the car is easily
accessible thanks to the folding
sport bucket seats.
Anti-theft protection.
The 911 GT2 has an engine
immobiliser with in-key transpon-
der as well as a powerful alarm
system featuring contact-sensitive
exterior protection and radar-
based interior surveillance as stan-
dard. The alarm system is
activated and deactivated by a
remote control function in the
ignition key.
Vehicle tracking system.
The 911 GT2 can also be equipped
with an optional factory-fitted
preparation enabling future
installation of a vehicle trackingsystem obtainable from Porsche
Tequipment. This system allows
a stolen vehicle to be traced
throughout most of Europe, and
requires the installation of a
special wiring loom and a high-
capacity battery.
Chrono Package Plus.
The optional Chrono Package Plus
combines a dash-mounted
analogue/digital timer with a range
of useful functions. Lap or journey
times can be viewed, stored and
analysed using the performance
display in PCM. The information
available includes time elapsed
and distance travelled on the cur-
rent lap, as well as the number
oflaps completed and their
respec-
tive times. You can also view the
current fastest lap and remaining
range till empty. Driving times can
be recorded for any stretch of
road, and benchmark times can be
defined. Other useful
features
include a personal
memory func-
tion, controlled via PCM, which
stores personal preferences for a
range of systems, including lights,
wipers, door locks and air condi-
tioning.
Luggage compartmentChrono timer

· 109 · · 108 ·The 911 GT2 |
Index
Index
A
ABS 51
Air conditioning, automatic 69
Airbags 62
Alarm system 75
Anti-theft protection 75
Audio system 76
B
Bi-Xenon lighting system 56
Bodyshell structure 60
BOSE® Surround
Sound System 80
Braking system 58
C
Catalytic converters 34, 85
Charge-air cooling 16
Chassis 42
Chrono Package Plus 75, 92
Clubsport package 64, 92
CO
284
Colours 88
Comfort 66
Communication 76, 96
Cruise control 74
D
Design 16
Drive 18
Dual-mass flywheel 39
E
Electronic logbook 78
Engine 20
Engine cooling 26
Engine management system 36
Environment 82
Exhaust emission control 85
Exhaust system 34
Expansion intake manifold 32
Exterior 91
F
Factory collection 100
Fire extinguisher 64, 93
Front axle 44
Fuel supply 35
Fuel system 35, 85
G
Gearbox, manual 38
GSM telephone module 78
H
HomeLink®74
I
Ignition system 35
Instruments 68
Interior 68, 93
Interior materials 70, 95
K
Knock control,
cylinder-specific 36
L
Launch Assistant 38
Leather 89, 95
Lightweight design 24
Loudspeakers 79, 80
Lubrication, dry-sump 25
Luggage compartment 74
M
Mobile phone preparation 79
N
Navigation module 77
Noise 85
O
Oil supply 25
On-board computer 69
Oxygen-sensor control 34, 85
P
ParkAssist 74, 90
Personalisation 86
Porsche Active Suspension
Management (PASM) 48
Porsche Ceramic Composite
Brake (PCCB) 58
Porsche Communication
Management (PCM) 76
Porsche Side Impact
Protection (POSIP) 62
Porsche Stability
Management (PSM) 50
R
Ram air principle 17
Rear axle 45
Rear wing 17
Recycling 84
Roll cage 64, 92
S
Safety 54
Safety, active 56
Safety, passive 60
Seats 72
Seats, adaptive sports 73, 92
Seats, sport bucket 15, 72
Service 102
Servicing 85
Six-cylinder twin-turbo
boxer engine 20, 24
Sound Package Plus 79
Sport tyres 46
Stability control (SC) 14, 50
Steering 52
Steering wheel 71
Storage compartments 73
T
Technical data 106
Telephone module 78
Traction control (TC) 14, 50
Transmission 38
Turbocharger 28
TV tuner 78
Tyre Pressure
Monitoring (TPM) 47
U
Universal audio interface 79
V
Variable Turbine
Geometry (VTG) 28
VarioCam Plus 26
Vehicle tracking system 75
Voice control system 78
W
‘Welcome Home’ lighting 74
Wheels 46