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Mar 16, 2007 1:31:50 PM
- Trundle_GT3
- Veteran
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- Loc: CA, USA
- Posts: 1016, Gallery
- Registered on: Jun 30, 2003
- Reply to: Pentium
Mar 16, 2007 6:40:02 PM
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Pentium
- Rennteam Master
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- Loc: Earth , Romania
- Posts: 3055, Gallery
- Registered on: Apr 27, 2003
- Reply to: Trundle_GT3
Re: 997 GT3 suspension setup
Here we go:
Information
The procedure for performing suspension alignment on the 911 GT3 is similar or often identical to the procedure used on the 911 Carrera (997). The main differences are as follows:
. Different adjustment values (vehicle height and wheel alignment values).
. The vehicle height of the 911 GT3 can be adjusted at the front and rear axle by means of the adjusting nut(s) on the corresponding spring strut or struts.
. Max. wheel-load difference from left to right on front and rear axle is less than 15 kg.
. For the measured-value pickups, electronic wheel alignment testers require spoiler adapters of 50 mm and 100 mm in length, depending on the wheel alignment tester. This is the only means of enabling data transfer from the right side to the left. Refer to operating instructions supplied by the alignment tester manufacturer if necessary!
. Front-axle camber setting: Unlike the 911 Carrera (997), a basic camber adjustment is made by means of intermediate plates on the 2-part control arm of the front axle on the 911 GT3. A 1-mm thick adjustment plate -Arrow- is fitted as standard on the right and left in the 911 GT3! Camber adjustment (fine adjustment) is carried out at the spring strut mount in the same way as for the 911 Carrera (997).
. Check all wheels for clearance after adjustment and assembly work!
General procedure for wheel alignment
Performing wheel alignment using an electronic wheel alignment tester. Measurement procedures should be taken from the operating instructions for the wheel alignment tester involved.
In order to exclude erroneous measurements, the following preconditions must be met before alignment and the following points should be given special attention:
Unladen weight of vehicle according to DIN 70020, i.e. vehicle in ready-to-drive condition with full tank and including tools but without driver or additional weights.
Ball-joint and wheel-bearing play in order (wheel-bearing play cannot be adjusted).
Tyre pressure in accordance with regulations, fairly uniform tyre tread.
Quick-clamping holder with adapter (for the measured-value pickups) correctly secured to the wheels.
Use self-centring quick-clamping holders → WE1265 Porsche Quick-Clamping Unit to secure the measured-value pickups on the wheels. Any previously used quick-clamping holders that are available can also be used.
The self-centring quick-clamping holders are positioned centrally (with the claws first) in the centre of the rim and are tautened in the rim by turning the straining ring (clockwise).
Receiving surfaces for the quick-clamping holder on the wheels and the adapter surfaces must be clean and flat. Always check the levelling surface on the wheels precisely in particular before fitting the quick-clamping holders.
Strictly comply with maintenance intervals for measuring equipment and measuring platform. If the levelling of the measuring platform or measuring station is done in-house, levelling equipment is required. A hose level gauge is not adequate.
Skilled handling of measuring equipment and measuring platform.
Sliding plates with transverse motion (rotary motion) at the rear axle are advisable.
Refer to the Technical Literature supplied by PAG, the manufacturer of the measuring equipment and the manufacturer of the measuring platform.
Do not treat measured values as a whole, but very critically with regard to driving dynamics, high-speed strength of the tyres, tyre wear and cost/benefit effects (time required for correction of insubstantial deviations). The toe values are of decisive significance for driving dynamics and tyre wear.
If the vehicle is measured front and rear, check and adjust the wheel alignment values at the rear axle first. Camber values at the front axle apply for the straight-ahead position of the wheels. Steering wheel and steering gear in centre position when toe is being adjusted.
Before wheel alignment values are adjusted on front and rear axles, it is recommended or required that the height adjustment be checked at the DIN empty weight. Height adjustment allows the wheel-load difference to be kept as low as possible, provided wheel-load weighing machines are available. The wheel-load difference is adjusted by changing the vehicle height within the height tolerance. The priority is to achieve the smallest possible wheel-load difference per axle from left to right. Conclusions can also be drawn about wheel alignment values in the event of any suspension alignment that becomes necessary later.
Before taking measurements and if the vehicle was previously raised or the setting was changed, quickly bounce the vehicle a few times on the rear and front axle. This is necessary in order to avoid getting incorrect measured results.
Check all wheels for clearance after adjustment and assembly work!
Preliminary work
1. Prepare the measuring station (combined rotary/sliding plates and weighing plates) and set it up on the wheel base.
2. Carry out measuring preparations (full tank, fill in washer fluid and set the prescribed tyre pressure).
3. Drive vehicle onto measuring station. Drive as carefully as possible to avoid bottoming the vehicle (the front spoiler).
Due to the reduced vehicle height, additional -stepped drive-on ramps and intermediate layers, if necessary- must be used to drive onto the floor-mounted measuring platforms. Measuring platforms without an inclination are unsuitable.
Information
The procedure for performing suspension alignment on the 911 GT3 is similar or often identical to the procedure used on the 911 Carrera (997). The main differences are as follows:
. Different adjustment values (vehicle height and wheel alignment values).
. The vehicle height of the 911 GT3 can be adjusted at the front and rear axle by means of the adjusting nut(s) on the corresponding spring strut or struts.
. Max. wheel-load difference from left to right on front and rear axle is less than 15 kg.
. For the measured-value pickups, electronic wheel alignment testers require spoiler adapters of 50 mm and 100 mm in length, depending on the wheel alignment tester. This is the only means of enabling data transfer from the right side to the left. Refer to operating instructions supplied by the alignment tester manufacturer if necessary!
. Front-axle camber setting: Unlike the 911 Carrera (997), a basic camber adjustment is made by means of intermediate plates on the 2-part control arm of the front axle on the 911 GT3. A 1-mm thick adjustment plate -Arrow- is fitted as standard on the right and left in the 911 GT3! Camber adjustment (fine adjustment) is carried out at the spring strut mount in the same way as for the 911 Carrera (997).
. Check all wheels for clearance after adjustment and assembly work!
General procedure for wheel alignment
Performing wheel alignment using an electronic wheel alignment tester. Measurement procedures should be taken from the operating instructions for the wheel alignment tester involved.
In order to exclude erroneous measurements, the following preconditions must be met before alignment and the following points should be given special attention:
Unladen weight of vehicle according to DIN 70020, i.e. vehicle in ready-to-drive condition with full tank and including tools but without driver or additional weights.
Ball-joint and wheel-bearing play in order (wheel-bearing play cannot be adjusted).
Tyre pressure in accordance with regulations, fairly uniform tyre tread.
Quick-clamping holder with adapter (for the measured-value pickups) correctly secured to the wheels.
Use self-centring quick-clamping holders → WE1265 Porsche Quick-Clamping Unit to secure the measured-value pickups on the wheels. Any previously used quick-clamping holders that are available can also be used.
The self-centring quick-clamping holders are positioned centrally (with the claws first) in the centre of the rim and are tautened in the rim by turning the straining ring (clockwise).
Receiving surfaces for the quick-clamping holder on the wheels and the adapter surfaces must be clean and flat. Always check the levelling surface on the wheels precisely in particular before fitting the quick-clamping holders.
Strictly comply with maintenance intervals for measuring equipment and measuring platform. If the levelling of the measuring platform or measuring station is done in-house, levelling equipment is required. A hose level gauge is not adequate.
Skilled handling of measuring equipment and measuring platform.
Sliding plates with transverse motion (rotary motion) at the rear axle are advisable.
Refer to the Technical Literature supplied by PAG, the manufacturer of the measuring equipment and the manufacturer of the measuring platform.
Do not treat measured values as a whole, but very critically with regard to driving dynamics, high-speed strength of the tyres, tyre wear and cost/benefit effects (time required for correction of insubstantial deviations). The toe values are of decisive significance for driving dynamics and tyre wear.
If the vehicle is measured front and rear, check and adjust the wheel alignment values at the rear axle first. Camber values at the front axle apply for the straight-ahead position of the wheels. Steering wheel and steering gear in centre position when toe is being adjusted.
Before wheel alignment values are adjusted on front and rear axles, it is recommended or required that the height adjustment be checked at the DIN empty weight. Height adjustment allows the wheel-load difference to be kept as low as possible, provided wheel-load weighing machines are available. The wheel-load difference is adjusted by changing the vehicle height within the height tolerance. The priority is to achieve the smallest possible wheel-load difference per axle from left to right. Conclusions can also be drawn about wheel alignment values in the event of any suspension alignment that becomes necessary later.
Before taking measurements and if the vehicle was previously raised or the setting was changed, quickly bounce the vehicle a few times on the rear and front axle. This is necessary in order to avoid getting incorrect measured results.
Check all wheels for clearance after adjustment and assembly work!
Preliminary work
1. Prepare the measuring station (combined rotary/sliding plates and weighing plates) and set it up on the wheel base.
2. Carry out measuring preparations (full tank, fill in washer fluid and set the prescribed tyre pressure).
3. Drive vehicle onto measuring station. Drive as carefully as possible to avoid bottoming the vehicle (the front spoiler).
Due to the reduced vehicle height, additional -stepped drive-on ramps and intermediate layers, if necessary- must be used to drive onto the floor-mounted measuring platforms. Measuring platforms without an inclination are unsuitable.
Re: 997 GT3 suspension setup
Aligning vehicle at front and rear
Vehicle height/wheel loads
The vehicle height on the front and rear axle of the 911 GT3 can be adjusted at the spring struts.
Adjusting the height means that different wheel loads on the left and right can be corrected.
At the correct height the wheel-load differences lie within a permissible range, provided that the coil springs have the same installation position (installed spring preload) on each axle. Tolerance 1 mm. Wheel-load differences can be kept as low as possible in conjunction with wheel-load weighing machines. Tolerance from right to left on front and rear axle is less than 15 kg.
To check the height of a ready-to-drive vehicle (full tank and tools, washer-fluid reservoir full), place the vehicle on a level surface or on the measuring station.
Required values for front and rear axle can be found in the table → 4400TW Adjustment values for suspension alignment.
Adjustments should be made with the axle raised. Taking the load off of the wheels makes it easier to make the adjustment (adjusting nuts on the spring strut are easier to turn and will not be visually damaged).
Basic information on height changes/wheel-load changes
When changing the height/wheel-load, the following must be noted:
. A one-sided height change causes a wheel-load change at the same time. A wheel-load change on one wheel also alters the wheel loads of the other wheels.
. A one-sided increase in the installed spring preload (raising vehicle) increases the wheel load.
. A one-sided decrease in the installed spring preload (lowering vehicle) decreases the wheel load.
. A change in the wheel-load is always transferred diagonally onto the other axle side. This means that if the wheel load on one wheel is decreased or increased, the same occurs on the diagonally opposite wheel.
. Max. wheel-load difference from left to right on front and rear axle is less than 15 kg.
. Example: Rear left spring preload is increased. As a result, the wheel load: rear left -C- and front right -B- is increased ---------- rear right -D- and front left -A- is reduced.
Front axle
From road contact surface to hexagon-head bolt of cross-member screw connection to the body.
Rear axle
Measure from wheel contact surface to the locating bore in the rear-axle side section (between toe and camber eccentrics).
Vehicle height/wheel loads
The vehicle height on the front and rear axle of the 911 GT3 can be adjusted at the spring struts.
Adjusting the height means that different wheel loads on the left and right can be corrected.
At the correct height the wheel-load differences lie within a permissible range, provided that the coil springs have the same installation position (installed spring preload) on each axle. Tolerance 1 mm. Wheel-load differences can be kept as low as possible in conjunction with wheel-load weighing machines. Tolerance from right to left on front and rear axle is less than 15 kg.
To check the height of a ready-to-drive vehicle (full tank and tools, washer-fluid reservoir full), place the vehicle on a level surface or on the measuring station.
Required values for front and rear axle can be found in the table → 4400TW Adjustment values for suspension alignment.
Adjustments should be made with the axle raised. Taking the load off of the wheels makes it easier to make the adjustment (adjusting nuts on the spring strut are easier to turn and will not be visually damaged).
Basic information on height changes/wheel-load changes
When changing the height/wheel-load, the following must be noted:
. A one-sided height change causes a wheel-load change at the same time. A wheel-load change on one wheel also alters the wheel loads of the other wheels.
. A one-sided increase in the installed spring preload (raising vehicle) increases the wheel load.
. A one-sided decrease in the installed spring preload (lowering vehicle) decreases the wheel load.
. A change in the wheel-load is always transferred diagonally onto the other axle side. This means that if the wheel load on one wheel is decreased or increased, the same occurs on the diagonally opposite wheel.
. Max. wheel-load difference from left to right on front and rear axle is less than 15 kg.
. Example: Rear left spring preload is increased. As a result, the wheel load: rear left -C- and front right -B- is increased ---------- rear right -D- and front left -A- is reduced.
Front axle
From road contact surface to hexagon-head bolt of cross-member screw connection to the body.
Rear axle
Measure from wheel contact surface to the locating bore in the rear-axle side section (between toe and camber eccentrics).
Re: 997 GT3 suspension setup
Wheel alignment
Rear-axle wheel alignment (camber and toe)
Prepare vehicle for checking and/or adjustment of wheel alignment values. Place front wheels on rotary table and rear wheels on rotary/sliding plates.
Before starting to take measurements, bounce the vehicle several times in quick succession on the front and rear axle. This is necessary in order to avoid getting incorrect measured results.
Front-axle wheel alignment
Adjusting front camber
Unlike the 911 Carrera (997), a basic camber adjustment is made by means of intermediate plates on the 2-part control arm of the front axle on the 911 GT3! A 1-mm thick adjustment plate -Arrow- is fitted as standard on the right and left in the 911 GT3!
Camber adjustment (fine adjustment) is carried out at the spring strut mount in the same way as for the 911 Carrera (997).
The 2-part control arms permit a correspondingly increased camber value to be obtained for circuit use. This is achieved using thicker adjustment plates.
Camber fine adjustment
The camber is adjusted by moving the spring strut transversely. For this purpose, loosen the three fastening nuts on the spring-strut mount and, to move the spring strut, remove the covering cap on the piston rod.
Adjusting caster
The caster is not adjustable on standard vehicles.
Toe-difference angle
The toe-difference angle is not adjustable.
Rear-axle wheel alignment (camber and toe)
Prepare vehicle for checking and/or adjustment of wheel alignment values. Place front wheels on rotary table and rear wheels on rotary/sliding plates.
Before starting to take measurements, bounce the vehicle several times in quick succession on the front and rear axle. This is necessary in order to avoid getting incorrect measured results.
Front-axle wheel alignment
Adjusting front camber
Unlike the 911 Carrera (997), a basic camber adjustment is made by means of intermediate plates on the 2-part control arm of the front axle on the 911 GT3! A 1-mm thick adjustment plate -Arrow- is fitted as standard on the right and left in the 911 GT3!
Camber adjustment (fine adjustment) is carried out at the spring strut mount in the same way as for the 911 Carrera (997).
The 2-part control arms permit a correspondingly increased camber value to be obtained for circuit use. This is achieved using thicker adjustment plates.
Camber fine adjustment
The camber is adjusted by moving the spring strut transversely. For this purpose, loosen the three fastening nuts on the spring-strut mount and, to move the spring strut, remove the covering cap on the piston rod.
Adjusting caster
The caster is not adjustable on standard vehicles.
Toe-difference angle
The toe-difference angle is not adjustable.
Re: 997 GT3 suspension setup
Adjustment values for suspension alignment
The following values relate to the empty weight, i.e. full fuel tank/fluid reservoirs, vehicle with tools, but without driver or additional weights!
Vehicle height
911 GT3/911 GT3 RS (997)
RoW/USA
Front axle
Height with 19-inch wheels
→ Adjustment value: 108 mm+ 5 mm- 0 mm → :
From road contact surface to lower edge of hexagon-head bolt of cross-member threaded connection to the body.
Rear axle
Height with 19-inch wheels
→ Adjustment value: 133 mm+ 5 mm- 0 mm → :
From wheel contact surface to the locating bore in the rear-axle side section (between toe and camber eccentrics).
Permitted transverse inclination of the vehicle: Max. difference in height, left to right = 5 mm.
Max. wheel-load difference from right to left on front and rear axle is 15 kg.
The following values relate to the empty weight, i.e. full fuel tank/fluid reservoirs, vehicle with tools, but without driver or additional weights!
Vehicle height
911 GT3/911 GT3 RS (997)
RoW/USA
Front axle
Height with 19-inch wheels
→ Adjustment value: 108 mm+ 5 mm- 0 mm → :
From road contact surface to lower edge of hexagon-head bolt of cross-member threaded connection to the body.
Rear axle
Height with 19-inch wheels
→ Adjustment value: 133 mm+ 5 mm- 0 mm → :
From wheel contact surface to the locating bore in the rear-axle side section (between toe and camber eccentrics).
Permitted transverse inclination of the vehicle: Max. difference in height, left to right = 5 mm.
Max. wheel-load difference from right to left on front and rear axle is 15 kg.
Re: 997 GT3 suspension setup
Stabiliser setting
Stabiliser position, front axle
Front stabiliser setting: 911 GT3/911 GT3 RS (997) = position -2- .
Adjustable front stabiliser, GT3
Stabiliser position, rear axle
Rear stabiliser setting: 911 GT3/911 GT3 RS (997) = position -3- (Figure shows position -2- ).
Stabiliser position, front axle
Front stabiliser setting: 911 GT3/911 GT3 RS (997) = position -2- .
Adjustable front stabiliser, GT3
Stabiliser position, rear axle
Rear stabiliser setting: 911 GT3/911 GT3 RS (997) = position -3- (Figure shows position -2- ).
Re: 997 GT3 suspension setup
The following values relate to the empty weight, i.e. full fuel tank/fluid reservoirs, vehicle with tools, but without driver or additional weights.
. The toe-difference angle value is also influenced by the vehicle height. For this reason the measured result must be evaluated accordingly. No action is necessary in the case of small deviations from the toe-difference angle's required value as long as the value to the right and left is almost the same.
Wheel alignment values
911 GT3/911 GT3 RS (997)
RoW/USA
Front axle
Toe unpressed (total)
+ 6' +- 2'
Toe difference angle at 20* lock
- 1* 50' +- 30'
Camber (with wheels in straight-ahead position)
- 1*20' +- 5'
max. difference, left to right
10'
Caster
8* +- 30'
max. difference, left to right
40'
Rear axle
Toe per wheel
+ 13' +- 2'
max. difference, left to right
5'
Camber 1)
- 1*40' +- 5' 1)
max. difference, left to right
10'
1) Altered camber value on the rear axle which is also valid retroactively (from start of production). Previous value: - 2* +- 5'.
. The toe-difference angle value is also influenced by the vehicle height. For this reason the measured result must be evaluated accordingly. No action is necessary in the case of small deviations from the toe-difference angle's required value as long as the value to the right and left is almost the same.
Wheel alignment values
911 GT3/911 GT3 RS (997)
RoW/USA
Front axle
Toe unpressed (total)
+ 6' +- 2'
Toe difference angle at 20* lock
- 1* 50' +- 30'
Camber (with wheels in straight-ahead position)
- 1*20' +- 5'
max. difference, left to right
10'
Caster
8* +- 30'
max. difference, left to right
40'
Rear axle
Toe per wheel
+ 13' +- 2'
max. difference, left to right
5'
Camber 1)
- 1*40' +- 5' 1)
max. difference, left to right
10'
1) Altered camber value on the rear axle which is also valid retroactively (from start of production). Previous value: - 2* +- 5'.
Re: 997 GT3 suspension setup
Lu, if you read this here are my two cents: either you find someone that do 911 GT3 suspension tuning for a living or forget it.
I know I will not leave my dealer to play with my susp. setup. It's not only one setting you need to adjust. Everything is related.
And if I can't rise the height I can't buy it so next car will be either a Turbo (I already hate myself for saying it) or a "mini-GT3": C2S+X51 with no "heavy weight options" like full leather, adaptive seats, sunroof, navigation, bose, etc. Just the minimum things I need.
And maybe some weigh treduction will also take place.
And I will wait to see the facelift first.
Roger and out.
I know I will not leave my dealer to play with my susp. setup. It's not only one setting you need to adjust. Everything is related.
And if I can't rise the height I can't buy it so next car will be either a Turbo (I already hate myself for saying it) or a "mini-GT3": C2S+X51 with no "heavy weight options" like full leather, adaptive seats, sunroof, navigation, bose, etc. Just the minimum things I need.
And maybe some weigh treduction will also take place.
And I will wait to see the facelift first.
Roger and out.
Re: 997 GT3 suspension setup
Thank you Pentium...wow that was mighty complex. I think I will leave it as it as per factory levels. What a great insight. Thanks for your help. Whats up with your roads? Are you in the US of A? Our roads aint that good either. Lately we've been having huge pot holes.
What face lift are you talking about?
What face lift are you talking about?
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