Over heating brakes-Stability control

[KennyL]

After experiencing 2 years of overheating brake problems I have discovered the problem is with the stability control.
I have cracked two sets of Brembo discs from the Gran Turismo upgrade kit ( now have 2 piece brake discs full floating with AP rotors ) and gone through more pads than you would believe to finally discover there is a stability control devise working even when traction control is turned off. At my last track day ( Brands GP ) after about six laps the brakes were overheated so I pulled two fuses out which shut this down and the brakes from then on were fine for the rest of the day. Does anyone know how this can be turned off in isolation as when fuses are removed other items are turned off such as speed related power steering control ABS etc along with lots of warning lights showing.

[Janner_Sy]

After experiencing 2 years of overheating brake problems I have discovered the problem is with the stability control.
I have cracked two sets of Brembo discs from the Gran Turismo upgrade kit ( now have 2 piece brake discs full floating with AP rotors ) and gone through more pads than you would believe to finally discover there is a stability control devise working even when traction control is turned off. At my last track day ( Brands GP ) after about six laps the brakes were overheated so I pulled two fuses out which shut this down and the brakes from then on were fine for the rest of the day. Does anyone know how this can be turned off in isolation as when fuses are removed other items are turned off such as speed related power steering control ABS etc along with lots of warning lights showing.

that simple then. you have a fault with your ESP cos i have never heard of anyone with that issue.

[KennyL]

Thanks for your input. Very helpful !

[Janner_Sy]

WTF. and that th second time. have you booked it into a garage to get a diagnosis

[DaveB@Vagbremtechnic]

There seems to be quite a bit of bluing on those they've got hot and then cold very quickly for that kind of metal fatigue to manifest itself. Purely from a curiosity point of view did the crack appear after the disc had cooled or in operation

Your GT calipers, are they the ones with the internal connecting pipe or do you have a pipe under your caliper.

If you have the newer design then it is possible that you have corrosion behind the pad slide plate, its caused by differential cooling between the caliper and the steel screwed in slide plate which the edge of the pad slides down.  The problem is a build up of dust and probably pad material behind the slide plate, this aint a problem in itself until it starts to corrode the ali caliper and the steel "bulges" preventing the pad from withdrawing. Its amazing how much force corrosion can generate.

Only thing is a full rebuild really, alternatively it could be a sticky piston - in either case it wont do any harm to strip down the caliper remove the corrosion, etch and re powder coat the calipers. If you do have a sticky piston then they are easily replaced from Porsche dealers about £25

[Msportman]

ESP will still be present with ESP switched off.

I have raced previously...not MK5 but you will get better heat distribution on a 2 piece set up but be warned that heat will travel down the FNS driveshaft and you 'may' suffer melting CV boots or worse a knack'd CV joint.
Get some ducting in there for sure.

What pads are you running?

When using Brembo drilled discs the holes drilled will ultimately cause cracking/weakening of the disc. Porsche use forged items hence they cost more but are resistant to track use. Slotted AP's should be good but track work will be equally cruel to big brake fits.I've been down this road before.

I think on a budget the OE discs possibly with a Cupra set using OE rotors will be cost effective with good high heat pads such as Pagid/Ferrodo/EBC etc and good fluid.

Did you notice lock up/ABS interviening?

Ian

[KennyL]

Not the best drive i've had coming back from germany where this happened the second time. The reason for the excessive heat is I am sure the stability control which apparently applies the brakes ( not that you would notice ) when it senses loss of traction etc. The brakes dont overheat when this is disabled and the car feels more responsive when exiting corners as if it is being held back slightly with stability control working. Would just like to know best way of turning this off without removing the fuses.

[KennyL]

Air ducting has been fitted.

Have tried EBC yellow, Ferodo 2500, Carbotec XP8 which were on the car at time of cracking, and Pagid RS29 along with different fluids that have all boiled including ATE Blue and Castrol SRF currently in the car.

The ABS system seems quite good, only very occasionally coming on, although thats partly to do with setup etc I guess .

[Hurdy]

Yes, you are right Kenny.

Even when the ABS is turned off the other functions still operate in the background and constantly apply the brakes to the wheel in most need to re-stabilise the car. It can do this several times over the course of a lap over and above what you will do when approaching corners. I did a 5 lap stint at Spa in the wet with R888's and my brakes were smoking when I pulled back into the pitlane. I had to go for a 10 min cooldown run to help chill them off!!!
Other than disconnecting the system via the fuses I haven't found a way to disable the functions in VCDS

[Poppa Dom]

Yes, you are right Kenny.

Even when the ABS is turned off the other functions still operate in the background and constantly apply the brakes to the wheel in most need to re-stabilise the car. It can do this several times over the course of a lap over and above what you will do when approaching corners. I did a 5 lap stint at Spa in the wet with R888's and my brakes were smoking when I pulled back into the pitlane. I had to go for a 10 min cooldown run to help chill them off!!!
Other than disconnecting the system via the fuses I haven't found a way to disable the functions in VCDS

Hope you did not put the handbrake on when you went into the pits John 

[KennyL]

Thanks Hurdy for your comments or maybe I should say support after one particular comment when I first posted this problem.

I guess as with all these problems they will only show up if the car is used in a particular fashion and thereby some people will never have this experience .

One option I have considered if all else fails is to have an in line switch fitted to disable the fuses for when I do track days as the car is used on a daily basis as well, but it would be great to be able to turn the system off in isolation.

Have you ever experienced the cutting out problem that I posted seperately ?

[RedRobin]

I did a 5 lap stint at Spa in the wet with R888's and my brakes were smoking when I pulled back into the pitlane. I had to go for a 10 min cooldown run to help chill them off!!!

....Strange, when I did my long stint (15 laps?) at Spa on that same wet day with the instructor in the passenger seat encouraging me to press on, I had the ESP off (as off as it ever gets with just the switch) and had no subsequent brake problems. [AP Racing BBK with Ferodo DS2500 pads and oem rear brakes]

I think the difference comes down to how hard you drive or at least how fast your car is. Your GTI is a much modified Ed30 with oodles more power than mine and you would doubtless be reaching much higher speeds and so braking much harder.

Kenny - You've just posted this as I was posting mine : -

I guess as with all these problems they will only show up if the car is used in a particular fashion and thereby some people will never have this experience .

....Which partly matches what I said about the difference in cars and hence driving. Hurdy is a very fast driver who really pushes it (but he is a safe driver).

[KennyL]

You are correct in what you are saying re- faster cars and drivers.

But its my understanding that even if you never applied the brakes for a whole lap the stability control would be doing this anyway.
The combination of stability control and heavy braking is over heating for me. When the system was disabled there was no overheating  no matter how hard I drove.( in my case that is )Every second quicker a car laps a track the more problems you are likely to experience.

I would just like to be able to turn it off without other things being affected.

[tony_danza]

The little gremlins in the ABS do faff around with your brakes, but I've kicked seven bells out of mine on track days and haven't had anything like that... melted pads, yes.

Is the geo right on the car? I had dodgy geo on an A3 once and it had a fit on fast slip roads and corners, got it sorted, stopped interferring.

[john_o]

from what Ive read there appear to be 2 levels of ESP off :
1. short press of button
2. >10sec press of button

is this correct ? and if so Kenny are you doing initiating mode 2?

I guess speaking to a company who race mk5's would ultimately be of the most help  e.g. VWR