Porsche 911 GT3 Cup 2008 Release Note

911 GT3 Cup
Technical Handbook, 2008 Model

Forward
This technical information will give you the possibility to reference
data, adjustment values and working procedures and make the
maintenance and repair work on the vehicle easier.
We wish you every success with your 911 GT3 Cup.
Dr.Ing.h.c. F. Porsche
Aktiengesellschaft
Vertrieb Sonder- und
Rennfahrzeuge

911GT3 Cup 2008 Model competition car
This car is specifically designed for participation in one-make cup
competitions.
For obvious reasons, measurements referring to bodywork
dimensions of the production cars cannot be used as reference.
Porsche accepts no guarantee that the vehicle conforms to the
regulations.
The car can not be registered for road use and does not comply
with German road traffic regulations.
Illustrations, descriptions and schematic drawings serve
exclusively as presentation for the text. Porsche Motorsport
accepts no liability for the completeness and conformity of the
contents of this brochure with respect to the legality of the
current regulations.

For guarantee refer to sales contract
Project Management
Manager Porsche Michelin Supercup Mr. Jens Walther Tel. [phone]
Assistant Fr. Jennifer Biela 0711 911-84096
Fax:[phone]
Service Mr. Stefan Rometsch Tel:[phone]
Fax:[phone]
Manager International Cup Mr. Gerd Schmid Tel. [phone]
Assistant Mr. Rene’ C. Maier 0711 911 82683
Technical assistance Mr. Rolf Huber 0711 911 82690
Fax [phone]
Manager Porsche Carrera Cup Mr. Helmut Greiner 0711 911 84074
Assistant Mrs. Andrea Hagenbach 0711 911 84041
Fax [phone]
Service Mr. Rainer Sauter Tel. [phone]
Fax [phone]
Sport parts sales
Mr. Kienle Tel. [phone]
Mr. Lenzner 0711 911 82423
Mr. Müller Bernd 0711 911 82687
Mr. Müller Christian 0711 911 89175
Mr. Scozzaro 0711 911 83738
Mr. Wöhr 0711 911 83363
Fax [phone]
The delivery of parts is made only against payment in cash or cash in advance.

Contents
General technical data 1
Technical engine data 2
Engine 3
Valve train / cam timing 7
Throttle reset 12
Engine tightening torques 13
Clutch 14
Gearbox 15
Gear ration chart 16
Gearbox disassembly 18
Gearbox assembly 22
Gear lever 30
Gearbox special tools . 32
Fluid capacities 33
Suspension 34
Maintenance and settings 35
Steering 36
Chassis tightening torques 39
Cooling system 42
Brake system 44
PCCB Brake system 47
Bodywork 50
Dashboard and electronic 51
Modas 58
Fire extinguisher 74
Safety instructions
Important safety instructions are markad in bold page
numbers
Only for Service CD:
To jump directly to a specific chapter click on the appropriate
line.
By using the arrow keys on the keyboard it is possible to page
through the chapter.
By pressing the “BACK” button at the bottom of every page it
is possible to return to the contents page.

1
General Technical Data
Chassis number: from WPO ZZZ 99 Z8S 7 98001
Car model: 997 830
Engine model: M 97/75
Gearbox model: G 97/ 60
Number of gears: 6
Weight
Dry weight: approx. 1170 kg
Dry weight Supercup (PCCB) approx. 1130 kg
Dimensions
Overall length (mm) 4450
Maximum width (mm) 1815
Wheelbase (mm) 2355
Front track width (mm) 1516
Rear track width (mm) 1561

2
Engine Technical Data
Engine model M97/75
Construction Six-cylinder boxer
Type of cooling water cooled
Number of cylinders 6
Cylinder bore (mm) 99.98
Stroke (mm) 76.4
Actual cubic capacity 3598 cm³
Compression ratio 12.0 (- 0.4):1
Maximum power 309 kW / 420 PS
Maximum power at 7500 r.p.m.
Maximum torque 410 Nm
Maximum torque at 6500 r.p.m.
Maximum engine revs in 1st to 6th gears 8400 r.p.m.

3
Valve timing
Inlet valve diameter (mm) 41
Inlet valve lift (mm) 12.5
Exhaust valve diameter (mm) 35.5
Exhaust valve lift (mm) 11.1
Maximum inlet valve lift 105° after TDC
Maximum exhaust valve lift 115° before TDC
Camshaft adjustment:
Set the camshaft timing with the camshaft timing and adjustment
tools.
Camshafts:
Inlet valve camshaft:Engine M 97/75 race component
Exhaust valve camshaft 911 GT3 RS
Camshaft housing:
Engine M 97/75 modified 911 GT3 RS production component
Piston/cylinder:
Piston clearance 0.02 – 0.05 mm
Crankcase:
Crankshaft: The two-piece aluminium alloy crankcase is a production
911 GT3 RS component. The forged crankshaft has 8 bearings.
Crankshaft bearings:
The crankshaft bearings are the same as those used in the 911GT3 RS
engine.
Notice:
The term 911 GT 3 RS refers to the production car version.

4
Connecting rod:
Because the connecting rods have a shot peened surface care must
be taken that no visible damage occurs when removing or fitting.
The connecting rod must not be polished.
Connecting rod bolts:
Attention: The connecting rod bolts must always be renewed
when the engine is completely overhauled. The surface of the
mating faces must not be damaged.
Tightening procedure:
Attention: The threads and mating faces must be lubricated with
engine oil.
Initial torque: 30 Nm +/- 10 % (mating torque)
Final torque: 1 x 60° +/- 2° torque angle
Piston:
The light-alloy pistons are 99.95 mm in diameter. The position of the
inlet valve pocket should be noted when fitting the piston. The
underside of the piston crown is cooled by sprayed oil. The weight
difference between all the piston/connecting rod assemblies must not
be greater than 5 grams.
Cylinder:
The cylinders are manufactured from a high-strength light-alloy with
Nicasil coating and have a bore of 99.98 mm.
Cylinder head:
The cylinder head is a GT3 RS production component.

5
Engine lubrication:
The 911 GT3 Cup engine is fitted with a dry sump lubrication system.
The oil tank is mounted to the engine.
An oil/water heat-exchanger is mounted to the engine (production GT3
RS).
1 – Oil tank 9 – Piston cooling
2 – Pressure pumps 10 – Timing chain tensioner
3 – Safety valve 11 – Camshafts
4 – Oil filter 12 – Hydraulic valve lifter
5 – Oil pressure gauge (Production) 13 – Crankcase scavenge pump
6 – Oil/water heat-exchanger 15 – Balance shaft
7 – Pressure relief valve 16 – Cylinder head supply pump
8 – Main bearing

6
Cylinder head mounting:
The following procedure must be adhered to when fitting the cylinder
head. The nut mounting faces and threads must be lightly oiled when
tightening.
1. Initial tightening to 30 Nm in accordance with tightening
sequence given below. Wait fifteen minutes before step 2.
2. Completely loosen all the nuts in reverse sequence.
3. Final tightening to 20Nm + 120° torque angle in the tightening
sequence given below.
Tightening sequence:

7
Valve timing
Inlet valve diameter 41 mm
Inlet valve lift 12.5 mm
Exhaust valve 35.5 mm
Exhaust valve lift 11.1mm
Maximum inlet valve lift 105° after TDC
Maximum exhaust valve lift 115° before TDC
Adjusting the valve timing on the GT3 Cup engine model
2008. Camshaft opening lead/closing lag (105° / 115°)
with special tool 000 721 996 10 and accessories.
Description:
Set cylinder number 1 to TDC using a dial gauge indicator
Fit degree wheel 996 450 131 00
Fit the camshaft 1 - 3 at the TDC exhaust / inlet valve
overlap and fix the inlet and exhaust valves with the special tool
000 721 966 10 with inlet special tool 996 450 *****, and
exhaust special tool 000 721 *****.
Mount the chain tensioning tool 00072194010.
Tighten camshaft wheels to approximately 30 Nm torque.
Remove the special tool from the camshaft slits.
Rotate the crankshaft 360°
Fit the camshaft 4 - 6 at TDC exhaust / inlet valve overlap
and fix the inlet and exhaust valves with the special tool
00072196610 with inlet special tool 9964501*****, and
exhaust special tool 000721*****.
Tighten camshaft wheel to approximately 30 Nm.
Remove the special tool from the camshaft slits.
Set engine to Cyl 1 TDC exhaust / inlet valve overlap
Rotate the engine three turns, and then pretension the chain
tension tool to the marks.

8
Set the cylinder 1 to exhaust / inlet valve overlap TDC.
Fit the special tool and, if necessary, correct the camshaft
position.
After tighten the timing chain sprockets as instructed
30 Nm + 90° torque angle.
Rotate the crankshaft 360°
Set the cylinder 4 to exhaust / inlet valve overlap TDC.
Fit the special tool and, if necessary, correct the camshaft
position.
After tighten the timing chain sprockets as instructed
30 Nm + 90° torque angle.
Attention:
Remove camshaft block before tightening.
When tightening hold the camshaft pulleys with special tool
00072196531.
Setting jig 000.721.966.10
Retaining spring, exhaust side 000.721.966.12
Retaining spring inlet side cylinder 1 – 3 996.450.*****
Retaining spring inlet side cylinder 4 – 6 996.450.*****
996.450.131.00

9
Valves:
The exhaust valves are sodium filled standard GT3 production
specification.
Exhaust system:
Exhaust system with cat-manifold (integrated catalytic converte) and
silencer.
Noise emissions are subject to country specific regulations.
Delivery version
without presilencer
Delivery version
including presilencer
Supercup version

10
Engine cooling:
The engine cooling is made by a water/oil heat-exchanger fitted to the
water cooling system.
Induction system:
Multi-stage – resonance – induction channel
Central air intake plenum
Replaceable air filter in boot lid
Attention:
The rubber sleeve in the connecting part must be removed when
racing in the rain.
Air filter element:
A
ttention:
Do not clean the air filter element with high-pressure.
Carefully remove the air filter element
Place the filter in a suitable water filled container.
Allow the filter to dry (without air pressure or hot air gun)
Afterwards impregnate the filter with filter oil spray.

11
Throttle cable adjustment:
The throttle cable adjustment is made on the connecting part
The two throttle cables are joined with the connecting piece in the
cockpit behind the drivers’ seat. This connection part removes the play
from the cables by means of a spring. The adjustment of the connection
part is carried out as described in step 1.
The throttle cable adjustment is made in 3 steps:
Tension free setting of throttle cable:
Unscrew the quick adjustment cap (1) to the thread stop.
The spring force automatically removes the play from both cables.
Tighten the screw cap (1) until it clicks clearly into place. In the closed
position, the marking on the screw cap must cover the marking 'Zu' on the
connection piece (2).

12
Re-setting the throttle
Re-setting the throttle is always necessary if the ECU or the throttle
sensor were changed or replaced.
•Disconnect throttle cable
•Rotate the knurled screw (idle adjustment screw) anti-clockwise
till a gap is visible between the cam-disc and the idle adjustment
screw (throttle completely closed).
•select warm up mode in Motec display
•press both menu button for 3 sec
•the Display show you “RESET” and 0,0
•Open throttle 6,5% with the idle adjustement screw (refer to
Motec display).
•Lock idle adjustment screw
•Connect throttle cable
•heck full throttle (refer to Motec display 100%
idle ad
j
ustin
g
srew
press both menu
button for 3 sec.
the Display show you
“RESET” and 0,0

13
Engine component tightening torques
All component tightening torques listed are given in Newton metres. Please ensure that your torque wrench is
calibrated correctly!
Crankshaft and crankcase:
Connecting rod
(see section connecting rod) M10 x 1.25 30Nm +60°
Oil pump M8 23
Crankcase studs M10 x 1.25 50
Crankcase nuts & bolts M8 23
Flywheel to crankshaft M10 x 1.25 90
Always renew bolts after flywheel removal
V-belt pulley to crankshaft M14 x 1.5 170
Plug screw for pressure release valve M18 x 1.5 40
Crankcase oil drain screw M20 x 1.5 50
Cylinder head and valve train:
The exact procedure for tightening the cylinder head bolts is described in
the section ‘Cylinder head’.
Camshaft housing on cylinder head
Initial torque M8 23
Final torque M8 28
Knock sensor on cylinder casting M8 23
Spark plugs M12 x 1.25 20
Attention: The spark plugs should be tightened a maximum of 5
times.
Camshaft pulley to camshaft M12 x 1.5 30 +90°
Timing chain case to crankcase 23
Valve cover to camshaft housing M 6 9.7
Camshaft bearing cap 13
Ancillary components:
Alternator belt pulley 55
Exhaust manifold to cylinder head 23
Lambda sensor M18 x 1.5 50
Clutch to flywheel M8 x 45 33

14
Clutch
5 ½” 3-plate sintered bronze clutch with central release
mechanism
Mounting instructions:
With multi-plate clutches care should be taken that the splined hub is as
well aligned as possible with the sintered plates.
(Special alignment tool, Porsche Nr. 996.450.335.90)
Smear the splines lightly with grease and slide the clutch plates along
the splined input shaft till the hub moves easily on the shaft. Remove
excess grease.
Make sure no grease is smeared on the clutch plates.
Wear:
Sintered clutch plate, new thickness 2.6 mm
Replace clutch plates when minimum thickness is: 2.2 mm
The diaphragm spring clamping force remains constant to this minimum
thickness, reduces when minimum thickness exceeded.
Fluid:
Endless RF - 650
Assembly diagram:

15
Gearbox G 97 / 63
The Porsche six-speed sequential gearbox is fitted with a limited slip
differential, and oil filter and a water / oil heat-exchanger for cooling
purposes. All gear ratio pairs can be changed individually to suit driver
preference, engine and the circuit characteristics. The gear pairs are
uniquely matched and should never be mixed. If one gear is damaged
the gear pair should be discarded.
Only one gear ratio set is allowed in the one-make cup races.
When filling the gearbox with oil for the first time, i.e. when the
complete system, including cooler, filter and oil lines are dry, the
system capacity is 3.6 litres. Following a gear ratio change only 3.0
litres of oil should be added. The use of Mobil ‘Mobilube’ SHC gearbox
oil is recommended.
Production gear ratio set:
Crown wheel and pinion 8/32
1st gear 12/38 997.302.961.6E
2nd gear 15/32 997.302.962.6C
3rd gear 18/31 997.302.963.6E
4th gear 20/28 997.302.964.6J
5th gear 23/26 997.302.966.9N
6th gear 29/27 997.302.966.9L
Limited slip differential:
The locking torque of the differential is 40 % (power) and 60 %
(braking) (Dynamic locking value).
The differential lock is checked by means of friction force
measurement in which the preload and wear of the clutch plates is
checked.
See page 18
Gearbox mounting:
A solid gearbox mount reduces the relative movement of the
complete drive train. The result is improved handling particularly
during weight transfer due to on/off throttle application. Using the
solid gearbox mounting increases the noise level in the cockpit.