Gt3 owners with gt2 rear sway bar
11-12-2011, 01:13 PM
#16
For this subset of drivers, the car's handling can also be mostly tweaked to their liking by running more front tire to get more front grip to get the car turned.
Everyone likes the car set up differently - the factory, given they also made the change in bars, 'probably' thinks they got the 07-08s a little under barred as well, but since no 2 drivers like the same setup, the GT2 rear bar is a quick fix for some.
There are some that soften the stock bar to fully soft and love it so this gives you an idea of the range of people's setup ranges.
11-12-2011, 01:21 PM
#17
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Even Porsche thought it was a good idea and made it official..
Technical Information Service 4
50/07 EN 4290
Dec 3, 2007
Approved rear-axle anti-roll bar
Model year: as of 2007
Vehicle Type: 911 GT3 (997)/911 GT3 RS (997)
Concerns: Approval of 911 GT2 rear-axle anti-roll bar.
Situation: The rear-axle anti-roll bar used on the 911 GT2 can also be fitted on the 911 GT3. For the special requirements associated with driving the vehicle on race circuits, the rear-axle anti-roll bar used on the 911 GT2 can also be fitted on the 911 GT3 at the request of the customer with immediate effect.The adjustable rear-axle anti-roll bar on the 911 GT2 has three different stability settings ranging from “soft” tuning ( -item 1- ) to “hard” tuning ( -item 3- ). Rear-axle anti-roll bar
Information
The rear-axle anti-roll bar used on the 911 GT2 is also approved for driving the vehicle on public roads.
Part Nos.: 997.333.701.94 → Rear-axle anti-roll bar
Procedure: Information
Follow the steps described in the Workshop Manual to replace the rear-axle anti-roll bar.
Even Porsche thought it was a good idea and made it official..
Technical Information Service 4
50/07 EN 4290
Dec 3, 2007
Approved rear-axle anti-roll bar
Model year: as of 2007
Vehicle Type: 911 GT3 (997)/911 GT3 RS (997)
Concerns: Approval of 911 GT2 rear-axle anti-roll bar.
Situation: The rear-axle anti-roll bar used on the 911 GT2 can also be fitted on the 911 GT3. For the special requirements associated with driving the vehicle on race circuits, the rear-axle anti-roll bar used on the 911 GT2 can also be fitted on the 911 GT3 at the request of the customer with immediate effect.The adjustable rear-axle anti-roll bar on the 911 GT2 has three different stability settings ranging from “soft” tuning ( -item 1- ) to “hard” tuning ( -item 3- ). Rear-axle anti-roll bar
Information
The rear-axle anti-roll bar used on the 911 GT2 is also approved for driving the vehicle on public roads.
Part Nos.: 997.333.701.94 → Rear-axle anti-roll bar
Procedure: Information
Follow the steps described in the Workshop Manual to replace the rear-axle anti-roll bar.
11-12-2011, 02:18 PM
#18
Many, although absolutely not all, believed that the 997gt3.mk1 and RS suffers from excessive push in as delivered form from the factory. Upon looking at the sways in as delivered setup, the rear bar is on the stiffest on its 3 settings and the front is on the 2nd softest of 5 settings. These subset of drivers, we're not able to get the handling they wanted by placing the front at full soft and were thus out of sway settings to try. When Porsche delivered the 2008 GT2 it had a thicker rear sway bar (30% stiffer) so a few people tried this bar and for them, it fixed what they wanted fixing.
For this subset of drivers, the car's handling can also be mostly tweaked to their liking by running more front tire to get more front grip to get the car turned.
Everyone likes the car set up differently - the factory, given they also made the change in bars, 'probably' thinks they got the 07-08s a little under barred as well, but since no 2 drivers like the same setup, the GT2 rear bar is a quick fix for some.
There are some that soften the stock bar to fully soft and love it so this gives you an idea of the range of people's setup ranges.
For this subset of drivers, the car's handling can also be mostly tweaked to their liking by running more front tire to get more front grip to get the car turned.
Everyone likes the car set up differently - the factory, given they also made the change in bars, 'probably' thinks they got the 07-08s a little under barred as well, but since no 2 drivers like the same setup, the GT2 rear bar is a quick fix for some.
There are some that soften the stock bar to fully soft and love it so this gives you an idea of the range of people's setup ranges.
What I would like some more elaboration on is; why not add more camber/toe to the front/rear to combat the problem? Where is the "understeer" cured, at entry, apex or exit? Does a stiffer rear end improve traction? Does it make turn-in better? I've been taught to trail-brake my gt3, is that why I am not seeing understeer? I miss understeer. It was a friendly way to find the limit of the car. How about movement in the rear of the car (the "squirming" under acceleration), does a stiffer bar do away with that?
Le help
11-12-2011, 02:18 PM
#19
Rennlist Member
Understeer is when you hit the wall with the front of the car. ---GT3.1
Oversteer is when you hit the wall with the rear of the car. ---GT2
So we take the bar of the mighty but slightly over-powered GT2 and put it in the GT3.1
And now we have a more balanced car and no wall.
Oversteer is when you hit the wall with the rear of the car. ---GT2
So we take the bar of the mighty but slightly over-powered GT2 and put it in the GT3.1
And now we have a more balanced car and no wall.
11-12-2011, 02:38 PM
#20
Rennlist Member
I've got my stock bar on middle, and front one off full stiff. Handling is great, if not a touch oversteery at the limit. I'd love for the car to change direction quicker, but it will never really be quick enough.
What I would like some more elaboration on is; why not add more camber/toe to the front/rear to combat the problem? Where is the "understeer" cured, at entry, apex or exit? Does a stiffer rear end improve traction? Does it make turn-in better? I've been taught to trail-brake my gt3, is that why I am not seeing understeer? I miss understeer. It was a friendly way to find the limit of the car. How about movement in the rear of the car (the "squirming" under acceleration), does a stiffer bar do away with that?
Le help
What I would like some more elaboration on is; why not add more camber/toe to the front/rear to combat the problem? Where is the "understeer" cured, at entry, apex or exit? Does a stiffer rear end improve traction? Does it make turn-in better? I've been taught to trail-brake my gt3, is that why I am not seeing understeer? I miss understeer. It was a friendly way to find the limit of the car. How about movement in the rear of the car (the "squirming" under acceleration), does a stiffer bar do away with that?
Le help
11-12-2011, 03:41 PM
#21
I've got my stock bar on middle, and front one off full stiff. Handling is great, if not a touch oversteery at the limit. I'd love for the car to change direction quicker, but it will never really be quick enough.
What I would like some more elaboration on is; why not add more camber/toe to the front/rear to combat the problem? Where is the "understeer" cured, at entry, apex or exit? Does a stiffer rear end improve traction? Does it make turn-in better? I've been taught to trail-brake my gt3, is that why I am not seeing understeer? I miss understeer. It was a friendly way to find the limit of the car. How about movement in the rear of the car (the "squirming" under acceleration), does a stiffer bar do away with that?
Le help
What I would like some more elaboration on is; why not add more camber/toe to the front/rear to combat the problem? Where is the "understeer" cured, at entry, apex or exit? Does a stiffer rear end improve traction? Does it make turn-in better? I've been taught to trail-brake my gt3, is that why I am not seeing understeer? I miss understeer. It was a friendly way to find the limit of the car. How about movement in the rear of the car (the "squirming" under acceleration), does a stiffer bar do away with that?
Le help
The 'squirming' issue is basically solved by
- replacing the engine mounts (wevo or other)
- replacing rear suspension rubber (upper control arms, lower control arm Monoballs and caster pucks, toe arms
- the car will no longer squirm and will be 'much easier' to drive nearer the limit
I also believe re-valving the suspension to prevent all the weight from moving around is very helpful.
My car, with the GT2 bar on soft (firmer than OE hard), and front bar on middle of 5 holes, with all of the other above stuff done, is far, far easier to drive fast, works at a variety of tire temps with never the feeling that the rear will come around.
My current alignment is -2.2f, -1.75 rear, zero front toe, very even tire wear on the track, car turns, is neutral, and doesn't snap lose. I generally run 31-35 front hot, 34-38 rear - car has very good grip on track out.
In the beginning of my journey with this car, I tried alignment and tire pressures to find that good balance - but it was too knife edge if I made it work with tire pressures and with alignment only, the tires were just not getting equal wear across the tires so by definition you are leaving grip on the table.
That's my story.
Last edited by 997gt3north; 11-12-2011 at 11:14 PM.
11-12-2011, 03:56 PM
#22
In my experience, the GT2 bar allows you to run 'proper' camber settings, front and rear, that lead to even tire wear and hot track tempts across the tire face - thus not using camber to fix a bar problem - and thus over all grip is better - and, a better range of tire
pressures work without basically leading to a slipper rear end - less camber, more grip and car turns without getting loose with to high rear temps.
The 'squirming' issue is basically solved by
- replacing the engine mounts (wevo or other)
- replacing rear suspension rubber (upper control arms, lower control arm Monoballs and caster pucks, toe arms
- the car will no longer squirm and will be 'much easier' to drive nearer the limit
I also believe re-valving the suspension to prevent all the weight from moving around is very helpful.
My car, with the GT2 bar on soft (firmer than OE hard), and front bar on middle of 5 holes, with all of the other above stuff done, is far, far easier to drive fast, works at a variety of tire temps with never the feeling that the rear will come around.
My current alignment is -2.2f, -1.75 rear, zero front toe, very even tire wear on the track, car turns, is neutral, and doesn't snap lose. I generally run 31-35 front hot, 34-38 rear - car has very good grip on track out.
In the beginning of my journey with this car, I tried alignment and tire pressures to find that good balance - but it was too knife edge if I made it work with tire pressures and with alignment only, the tires were just not getting equal wear across the tires so by definition you are leaving grip on the table.
That's my story.
pressures work without basically leading to a slipper rear end - less camber, more grip and car turns without getting loose with to high rear temps.
The 'squirming' issue is basically solved by
- replacing the engine mounts (wevo or other)
- replacing rear suspension rubber (upper control arms, lower control arm Monoballs and caster pucks, toe arms
- the car will no longer squirm and will be 'much easier' to drive nearer the limit
I also believe re-valving the suspension to prevent all the weight from moving around is very helpful.
My car, with the GT2 bar on soft (firmer than OE hard), and front bar on middle of 5 holes, with all of the other above stuff done, is far, far easier to drive fast, works at a variety of tire temps with never the feeling that the rear will come around.
My current alignment is -2.2f, -1.75 rear, zero front toe, very even tire wear on the track, car turns, is neutral, and doesn't snap lose. I generally run 31-35 front hot, 34-38 rear - car has very good grip on track out.
In the beginning of my journey with this car, I tried alignment and tire pressures to find that good balance - but it was too knife edge if I made it work with tire pressures and with alignment only, the tires were just not getting equal wear across the tires so by definition you are leaving grip on the table.
That's my story.
Funny, we have almost an identical alignment. I have 1.7 in the rear, instead of 1.75, but 2.2 in the front. I don't want to go more aggressive because I like driving my car on the street
I have about 0.5mm total toe out in the front, but honestly thats just a psychological number... I think I should just straighten it out completely 
Anyway, I have the RSS control arms and toe links and liked what they do. What does re-valving the suspension do?
11-12-2011, 11:24 PM
#23
There is an entire tread detailing my shock re-valving and going to higher front and rear springs. Shocks were sent out to Bilstein, they were re-valved to match #600/#900 f/r springs and Ira at Tarett Engineering developed a new rear spring hat that allows standard 60mm springs to be fit. The shocks retain their 2 settings.
Search for the tread - all my thoughts are there.
<--------- see the picture left - that is what my rear setup looks like
11-13-2011, 08:57 AM
#25
In my experience stiffer sways/sway settings kept in balance can significantly improve the handling in corners - but does nothing for acceleration squat or braking nose dive - stiffer springs and shocks help there (and in corners).
11-13-2011, 10:35 AM
#26
Rennlist Member
Torque determines how far you take the wall with you...
Might as well complete the definitions
11-13-2011, 11:22 AM
#27
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11-13-2011, 12:44 PM
#28
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Is mid position on the ~GT2 bar actually stiffer than the stock bar on full stiff, not sure that adds up? Any way, the car handles better with a softer rear bar in my opinion but it does depend on the rest of the geo obviously. I run 2' rear, 2.5' front, rear (stock) bar in the middle and front bar 1 from full stiff. With a cup diff if it understeers you can dial some out on the throttle. As long as you haven't gone in too hot in the first place.
