2010 GT3 brakes
Discussion
Brand new discs/pads all around. One track day and a few hundred miles later I get this vibration on the front at around 50-70mph. Figured bad discs from the factory and had OPC change them.
Put on two track days at SPA on the new discs and a few hundred miles later get the vibration again only worse. Brakes have to warm up so clearly must be the disc.
Anybody have this problem?
Put on two track days at SPA on the new discs and a few hundred miles later get the vibration again only worse. Brakes have to warm up so clearly must be the disc.
Anybody have this problem?
It is perfectly possible that you are killing your brakes in short order. The added grunt with the 3.8 makes it easier. TC also can work the brakes more than you think.
How sure are you that its the brakes and not something else? Disappeared completely after the last parts change and now back?
As a general brake insight, work on warming things up better as its this phase when the thermal shock kicks in. Cool down laps only help you with heat soak issues (ie killing your fluid and dust seals) while parked.
Other than that, look at your braking technique. There are plenty of people very fast in these cars who are not killing brakes in such a short time so if there is no technical issue causing your situation then you need to look at your approach. Much less braking would be an obvious solution
How sure are you that its the brakes and not something else? Disappeared completely after the last parts change and now back?
As a general brake insight, work on warming things up better as its this phase when the thermal shock kicks in. Cool down laps only help you with heat soak issues (ie killing your fluid and dust seals) while parked.
Other than that, look at your braking technique. There are plenty of people very fast in these cars who are not killing brakes in such a short time so if there is no technical issue causing your situation then you need to look at your approach. Much less braking would be an obvious solution
Pad deposit on the rotors. I'm guessing you have got the brakes very hot and whilst at this temp you have sat stationary with your foot on the brakes. It doesn't have to be long to transfer to the rotor and leave a mark. Thus every time that bit of the rotor comes through the caliper it has a different coefficient of friction manifesting itself in a vibration. The cure is to get the rotors and pads smoking hot or swap to a more aggressive non OEM pad to clear the deposits off the rotor.
OP, I've had quite a bit of unfortunate experience with this and in my case it was all my fault and to do with the discs getting too hot and warping, then the pads melting deposit on to the disc, but not from sitting with foot on brake as described above. The rear brake bias is very strong on the Gen2, and for me it was the stability control that was effectively killing the brakes on track as we know all 911s like to move around a bit and on the GT3 you're able to do this far more, however the SC is constantly working in that environment and therefore it only takes 5-6laps of somewhere like Spa to warp the discs if SC is constantly fighting the yaw induced by a car such as the GT3.
So like you OP I went through quite a few sets of discs before finally figuring out what was happening. It had never happened on any of my other pork so I was quite puzzled and blamed the discs, the pads and just about everybody else other than me.
I decided to switch off the TC & SC and whilst you're never aware what the TC/SC is doing (unless you have a moment) the difference in drivability with everything switched off is amazing and the car flows so much better. No issues ever again with brakes after I did this. Now I leave on the TC, so just do the first stage switch off of aids, to have a partial safety net and I'm not having problems with the brakes anymore. One final point, the warped rears would often feel like it was the fronts that were warped.
The Gen2 is very easy to correct compared with previous cars so don't be scared to switch off the aids and the car will definitely flow better and feel more stable once you do this, it was a eureka moment for me and my wallet is more healthy too now!
Hope that's of help OP.
PF
So like you OP I went through quite a few sets of discs before finally figuring out what was happening. It had never happened on any of my other pork so I was quite puzzled and blamed the discs, the pads and just about everybody else other than me.
I decided to switch off the TC & SC and whilst you're never aware what the TC/SC is doing (unless you have a moment) the difference in drivability with everything switched off is amazing and the car flows so much better. No issues ever again with brakes after I did this. Now I leave on the TC, so just do the first stage switch off of aids, to have a partial safety net and I'm not having problems with the brakes anymore. One final point, the warped rears would often feel like it was the fronts that were warped.
The Gen2 is very easy to correct compared with previous cars so don't be scared to switch off the aids and the car will definitely flow better and feel more stable once you do this, it was a eureka moment for me and my wallet is more healthy too now!
Hope that's of help OP.
PF
mrdemon said:
I doubt any of these disks are warped.
very very hard to warp a disk
Having personally warped a number of disks on 2010 GT3s, can I please ask you to stay with the Boxster threads Mr D. Your inexperience of the Gen2 997 isn't really helpful.very very hard to warp a disk
The 997.2 GT3 can do this - it is one of its weak points and I know of a number of cases (CS, RS and 4 litre) that have done it. Live with the vibration if it isn't too bad, otherwise have them skimmed or scrap them I am afraid. The root cause seems to be related to uneven pad transfer. Happens to both OE and aftermarket disks, making the why part a bit of a puzzler (and if it is any driver related factor it didn't do that on over a half decade of track time in 996 GT3s). May or may not be related to the weak diff, fragile hubs or PSM system. Some people don't get it at all so I even wonder if it is QC related to something in the hub assembly (not that I can see how)?
Doesn't appear to happen if everything is stock, but used properly the stock pads don't last 2.5 days so that isn't much of a solution either. Personally I've warped disks with both Pagid and Endless pads and both OE and Alcon disks. I am starting to get somewhat frustrated by it as frankly it shouldn't be possible.
Footnote: I've warped both fronts and rears. If it were rears only the PSM/TC would be a much more viable candidate.
Footnote 2: I've yet to hear of this affecting 997.1 GT3s (where the TC is known to eat rear pads). In the 997 I wear front to rear pads about 1:1 (used to be more like 3:2 on a 996 without PSM/TC, but the rear brake bias ought to account for that, implying that I am not leaning on the driver aids much. Heavy booted drivers ofter do rear pads appreciably faster than front on a 997).
Edited by DiscoColin on Sunday 6th April 22:01
The first front set of rotors had 600 miles of bedding in, one cold/wet track day at Silverstone on Michelin Cups. So slow and rotors got nowhere near hot. Vibration started a few hundred miles after track day.
Set #2 about 800 miles of bedding in, 2 days at SPA and vibration started about 1200 miles after. Steering wheel is about to fall out the window now when I hit the brakes. Nothing looks to be loose.
I cannot believe they are warped really unless they are made out of chocolate. I suspect the connection between the hub and the rotor. Those pins which make the connection look a bit suspect.
Set #2 about 800 miles of bedding in, 2 days at SPA and vibration started about 1200 miles after. Steering wheel is about to fall out the window now when I hit the brakes. Nothing looks to be loose.
I cannot believe they are warped really unless they are made out of chocolate. I suspect the connection between the hub and the rotor. Those pins which make the connection look a bit suspect.
Edited by mm450exc on Monday 7th April 20:19
DiscoColin said:
Having personally warped a number of disks on 2010 GT3s, can I please ask you to stay with the Boxster threads Mr D. Your inexperience of the Gen2 997 isn't really helpful.
The 997.2 GT3 can do this - it is one of its weak points and I know of a number of cases (CS, RS and 4 litre) that have done it. Live with the vibration if it isn't too bad, otherwise have them skimmed or scrap them I am afraid. The root cause seems to be related to uneven pad transfer. Happens to both OE and aftermarket disks, making the why part a bit of a puzzler (and if it is any driver related factor it didn't do that on over a half decade of track time in 996 GT3s). May or may not be related to the weak diff, fragile hubs or PSM system. Some people don't get it at all so I even wonder if it is QC related to something in the hub assembly (not that I can see how)?
Doesn't appear to happen if everything is stock, but used properly the stock pads don't last 2.5 days so that isn't much of a solution either. Personally I've warped disks with both Pagid and Endless pads and both OE and Alcon disks. I am starting to get somewhat frustrated by it as frankly it shouldn't be possible.
Footnote: I've warped both fronts and rears. If it were rears only the PSM/TC would be a much more viable candidate.
Footnote 2: I've yet to hear of this affecting 997.1 GT3s (where the TC is known to eat rear pads). In the 997 I wear front to rear pads about 1:1 (used to be more like 3:2 on a 996 without PSM/TC, but the rear brake bias ought to account for that, implying that I am not leaning on the driver aids much. Heavy booted drivers ofter do rear pads appreciably faster than front on a 997).
I would like to see proof of a warped disk and not just uneven pad transfer causin a vibration.The 997.2 GT3 can do this - it is one of its weak points and I know of a number of cases (CS, RS and 4 litre) that have done it. Live with the vibration if it isn't too bad, otherwise have them skimmed or scrap them I am afraid. The root cause seems to be related to uneven pad transfer. Happens to both OE and aftermarket disks, making the why part a bit of a puzzler (and if it is any driver related factor it didn't do that on over a half decade of track time in 996 GT3s). May or may not be related to the weak diff, fragile hubs or PSM system. Some people don't get it at all so I even wonder if it is QC related to something in the hub assembly (not that I can see how)?
Doesn't appear to happen if everything is stock, but used properly the stock pads don't last 2.5 days so that isn't much of a solution either. Personally I've warped disks with both Pagid and Endless pads and both OE and Alcon disks. I am starting to get somewhat frustrated by it as frankly it shouldn't be possible.
Footnote: I've warped both fronts and rears. If it were rears only the PSM/TC would be a much more viable candidate.
Footnote 2: I've yet to hear of this affecting 997.1 GT3s (where the TC is known to eat rear pads). In the 997 I wear front to rear pads about 1:1 (used to be more like 3:2 on a 996 without PSM/TC, but the rear brake bias ought to account for that, implying that I am not leaning on the driver aids much. Heavy booted drivers ofter do rear pads appreciably faster than front on a 997).
Edited by DiscoColin on Sunday 6th April 22:01
Ie a report from Alcon that you have sent them a warped disk back and it's been confirmed warped.
Infact I,ll send my contact in the Motorsport dept at Alcon a email and ask him myself.
For MrDemon's benefit, at the time I had JZM send my warped disks back to Alcon. A week later all they could offer was a bit of supposition that added nothing to what we already knew. Having used and advocated the product for about 7 years I was pretty disappointed that they didn't seem terribly bothered. The level of vibration that we are talking about could not be attributed to pad transfer either, though that is certainly a related issue. I could demonstrate the effect with video, but I really cannot be bothered.
For Ruedbo - no, ceramic disks are not actually made out of metal and thus don't warp. The issues with ceramics are the subject of a plethora of other threads so I won't drag this one down that path, but when they die it is from failure of the surface rather than distortion of the rotor.
For mm450exc - Rear disks warping is known to have happened with OE rotors and Alcons in both standard 350 and the larger 362mm sizes on the rear. I don't know of any warping of PF disks, though I have heard of cases of similar (but much lesser) vibration from uneven pad transfer on those. All of the warped disks were on Gen 2 cars - I've not heard of the issue with the Gen 1 (though that can be susceptible to pad transfer issues). On the subject of uneven pad transfer - non-issue for Endless MX72 but the price is horrific. Also no problem with the OE pads, but as said - they last less than 3 days. The worst for it that I have tried are the Pagid RSL1. Much less so with the RS29 but still can happen on those. If I was going to make a recommendation to someone else right now I would say to try the Performance Frictions or Brembo race disks simply as I know plenty of people who are happy with them and nobody who has had this specific issue.
I am currently on Alcons (the rears having been replaced after the first instance, but I've also had them skimmed since) and RS29s. They are currently a bit grumbly (more than I would normally expect) but they aren't transmitting cabin vibration the way that warping does and are working okay at the moment.
The only other thing that I am aware of that can cause worrying levels of vibration such as this are (i) if the diff plates start to break up or (ii) if the central hub bolt has loosened (Manthey discovered a minor case of this on a friend's car while attending to something else and say that it does happen. Needs a 30mm deep socket to do IIRC. Note - talking about the hub here, not the wheel nut).
Hope all of that is of some value to some of you.
For Ruedbo - no, ceramic disks are not actually made out of metal and thus don't warp. The issues with ceramics are the subject of a plethora of other threads so I won't drag this one down that path, but when they die it is from failure of the surface rather than distortion of the rotor.
For mm450exc - Rear disks warping is known to have happened with OE rotors and Alcons in both standard 350 and the larger 362mm sizes on the rear. I don't know of any warping of PF disks, though I have heard of cases of similar (but much lesser) vibration from uneven pad transfer on those. All of the warped disks were on Gen 2 cars - I've not heard of the issue with the Gen 1 (though that can be susceptible to pad transfer issues). On the subject of uneven pad transfer - non-issue for Endless MX72 but the price is horrific. Also no problem with the OE pads, but as said - they last less than 3 days. The worst for it that I have tried are the Pagid RSL1. Much less so with the RS29 but still can happen on those. If I was going to make a recommendation to someone else right now I would say to try the Performance Frictions or Brembo race disks simply as I know plenty of people who are happy with them and nobody who has had this specific issue.
I am currently on Alcons (the rears having been replaced after the first instance, but I've also had them skimmed since) and RS29s. They are currently a bit grumbly (more than I would normally expect) but they aren't transmitting cabin vibration the way that warping does and are working okay at the moment.
The only other thing that I am aware of that can cause worrying levels of vibration such as this are (i) if the diff plates start to break up or (ii) if the central hub bolt has loosened (Manthey discovered a minor case of this on a friend's car while attending to something else and say that it does happen. Needs a 30mm deep socket to do IIRC. Note - talking about the hub here, not the wheel nut).
Hope all of that is of some value to some of you.
DiscoColin said:
Footnote 2: I've yet to hear of this affecting 997.1 GT3s (where the TC is known to eat rear pads). In the 997 I wear front to rear pads about 1:1 (used to be more like 3:2 on a 996 without PSM/TC, but the rear brake bias ought to account for that, implying that I am not leaning on the driver aids much. Heavy booted drivers ofter do rear pads appreciably faster than front on a 997).
I have some track days coming up in my car and although I don't push it I've tended to turn off both the TC and PSM because of what I've heard about the rear brakes.Edited by DiscoColin on Sunday 6th April 22:01
Is it the TC and/or PSM that causes it? Is there any sense in just turning off TC or will that not help?
arcamalpha said:
DiscoColin said:
Footnote 2: I've yet to hear of this affecting 997.1 GT3s (where the TC is known to eat rear pads). In the 997 I wear front to rear pads about 1:1 (used to be more like 3:2 on a 996 without PSM/TC, but the rear brake bias ought to account for that, implying that I am not leaning on the driver aids much. Heavy booted drivers ofter do rear pads appreciably faster than front on a 997).
I have some track days coming up in my car and although I don't push it I've tended to turn off both the TC and PSM because of what I've heard about the rear brakes.Edited by DiscoColin on Sunday 6th April 22:01
Is it the TC and/or PSM that causes it? Is there any sense in just turning off TC or will that not help?
The 7.2RS has so much mechanical grip and understeer is nearly dialled out completely so it's quite easy to move the car around with confidence...the key, as you know, is to keep it smooth and balanced and it shouldn't bite you, but like all things only you can decide to switch off all aids. I took me a long time to gain confidence to do this, but was amazed how different the car felt (better) when I finally did it and then felt a bit daft that I hadn't been aware of SC interfering.
Good luck with it
PF
shaunRS said:
When getting them fitted I was not best please about the surprise additional cost to replace the disc alignment pins, £115+vat per corner.... Apparently the workshop manual states this must be done every time you change discs on centrelock wheels.
What part number is that?NBTBRV8 said:
shaunRS said:
When getting them fitted I was not best please about the surprise additional cost to replace the disc alignment pins, £115+vat per corner.... Apparently the workshop manual states this must be done every time you change discs on centrelock wheels.
What part number is that?It is recommended, but few would say that it was actually necessary to change it all at every disk change. If not though, condition should be inspected carefully.
Gassing Station | Porsche General | Top of Page | What's New | My Stuff