Brakes overheating on trackdays

[Wollemi]

I've just had to have discs and pads replaced on my 987.2 Boxster S after 5000 miles and 6 trackdays. The pads were crumbling due to overheating. To be fair the discs could have gone on for longer but they were a little warped.
Im looking for advice as to how to manage this, apart from not braking, and going faster round every corner. I will try that. I do know about cool down laps and not resting foot on brake and leaving the hand brake on. I usually only do one cool down lap; should I do more?
My car is still under Porsche warranty, my OPC have said that I could change pads but obviously other modifications are not allowed. Any thoughts on pads; as I am a mechanical incompetent I don’t want to have to change pads just for trackdays so would want something that I can full time.
It‘s been suggested that I monitor the temperature with a laser pyrometer but what is the safe operating temperature for the standard brakes and pads?
any advice gratefully received.

[Wollemi]

Thanks for that, cmoose, looks like i might have to buy myself a jack! and a torque wrench I suppose.

[v8ksn]

Are you driving with the traction control on or off?

[skinny]

6 trackdays sounds ok for std pads to me.

But you can just get some specific track pads and use them just for that then back to road pads for the road. Racing brake fluid should not invalidate anything as it'll still be dot4 or 5.1

[CrashBang]

Start with brake fluid, Castrol SRF or Motul RBF660 both have high boiling points.

Brake ducts, fit bigger GT3 items, they are only a few pounds from OPC.

Brake pads, better pads will squeal on the road as you won't get heat in them, so you either live with the squeal or swap out when doing a track day. Pagid Yellow (RS29) are very good but very noisey on the road and need a good heat cycle to bed them. A good duel use is Pagid Blue (RS4-2).

[dontdobends]

The RS14 pads worked well for me in the cayman, when I had it on track with no fade.

I when through 2 sets of standard disc's in 10k miles with the heat cracks.

[nsa]

As others said, Pagid RS29s. They are expensive - over £200 a set - but worth it.

[911-32]

I am running Carbon Lorraine RC5+ pads in my boxster and they every bit as good as the more expensive Pagids or Performance Friction race pads I have run before. Yes there is a little squeal, but not as bad as other race pads in my experience. Dust is ok, unlike the PFs for example where it is prolific and sets like concrete.

Just another option to consider.

[ChrisW.]

cracking of the pads is clearly heat soak from the discs ... GT3 ducts will help and two cooling down laps will help even more ...

But six track days from a set of pads can't be sneezed at ... how many do you get out of a set of tyres ?

As for warped discs ... two cooling down laps will definitely help.

A pyrometer will only tell you how hot everything is getting after the event.

And yes, PSM may overheat the rears .... but it is a safety net that for many is worth keeping. If it is working you need it, if it isn't, there is no heat !

[timg4d]

If you decide to go for Pagid RS pads, it 's probably best to get them pre-bedded in. The bedding in procedure is not really practicable on public roads (involves braking 5 times from 112 to 37mph).

[Wollemi]

ChrisW. said:

cracking of the pads is clearly heat soak from the discs ... GT3 ducts will help and two cooling down laps will help even more ...

But six track days from a set of pads can't be sneezed at ... how many do you get out of a set of tyres ?

As for warped discs ... two cooling down laps will definitely help.

A pyrometer will only tell you how hot everything is getting after the event.

And yes, PSM may overheat the rears .... but it is a safety net that for many is worth keeping. If it is working you need it, if it isn't, there is no heat !

I don’t drive my car to the ragged edge, I go to track days to have a good time driving harder and faster than is sensible on the public road but I certainly don’t wish to risk damaging my very precious car!

Tyres, - the first set did 2 trackdays and 9,000 miles the second eight trackdays and 8,200 miles which seems quite reasonable.

The pads that were replaced due to crumbling were still at 8mm front, 7mm rear so not badly worn at all. The discs were not really bad, a local independent that I showed them to said they would have let them stay on for longer.

I have to admit that I hadn’t really considered the whole issue of PSM on or off before. I’ve always kept it on on the basis of if it’s working I probably need it - I’m not sure I trust my skills enough. If I binned the car with it off I would feel a chump.

It’s been really interesting to hear everyone advice, I think I will have to look at harder pads but fitting the GT3 cooling ducts sounds sensible; what is involved in doing that please?

[88racing]

GT3 ducts are the cheapest mod you can make. Get them from Porsche - they’re only a few quid. They just clip onto the lower suspension arms, although I suggest you cable tie them on, as I did mine which was years ago.

Next, as already suggested, get some race spec brake fluid - the Porsche stuff isn’t up to it. Castrol is the best but is frighteningly expensive; consider Motul or Performance Friction.

PSM can muller you pads so turn it off and you’ll benefit for learning car control at the same time. PTV is worse and I don’t think can be defeated.

You may need to look at improving your braking technique too. Unless it’s wet, braking should be late and hard. Don’t be slowing for half the straight with the brakes partly on.

[gadgit]

Just out of interest, when I did test days the advice given was that 10 laps was regarded as about enough for a run, and then rest.
When I ran a f3 car it was also advised that on testing you should run 2 laps quite hard and then come in and check the brake temperatures. If all is good, then off you go for ten laps.
Concerning pads, if you want great brakes you are going to produce more heat, and I'm sure you understand that something is going to get hot.
My question is, as I have never done a track day, what do they advise at the briefing about times on the track and how to control your brake temperatures.
Or don't they bother?
Just be intetesting to know.

Gadgitn

[Wollemi]

gadgit said:

Just out of interest, when I did test days the advice given was that 10 laps was regarded as about enough for a run, and then rest.
When I ran a f3 car it was also advised that on testing you should run 2 laps quite hard and then come in and check the brake temperatures. If all is good, then off you go for ten laps.
Concerning pads, if you want great brakes you are going to produce more heat, and I'm sure you understand that something is going to get hot.
My question is, as I have never done a track day, what do they advise at the briefing about times on the track and how to control your brake temperatures.
Or don't they bother?
Just be intetesting to know.

Gadgitn

I've only done PCGB track days, but on those days the advice is usually to do sessions of 15 to 20 minutes max and do a cool down lap before coming in., with warnings not to put the handbrake on or sit with your foot on the brake.

[ChrisW.]

This does sound like classic overheating ... two cooling down laps would certainly help ... as would larger brake cooling ducts ...

I wouldn't leave PSM or PTV off ...

[Steve Rance]

Your technique will make a big difference. An experienced track driver will brake late, very hard and come off of the brakes (or begin to bleed off) quickly. He or she will ask a lot from the brakes but for relatively short periods as it’s the method that will bring the quickest lap time. More inexperienced drivers tend to brake softer but earlier which transfers more heat into the pad and disc and allows less time for them to cool before the next application. This was highlighted when the 996GT3 was first launched. A lot of drivers were complaining of overheating brakes but experienced drivers reported that they were fine. Porsche eventually asked a works driver to drive a complainants car to get to the bottom of it. I believe that the driver was Alan Mcnish. He did some very quick laps in the car with no problems. The owner jumped in and within a few laps he started to experience problems. Alan reported that the customers braking zone was almost twice as long and the brakes couldn’t cope with it. When the 996GT3 Gen 2 was launched the 4 pot fronts of the gen 1 were replaced with 6 pots.

[gadgit]

Steve Rance said:

Your technique will make a big difference. An experienced track driver will brake late, very hard and come off of the brakes (or begin to bleed off) quickly. He or she will ask a lot from the brakes but for relatively short periods as it’s the method that will bring the quickest lap time. More inexperienced drivers tend to brake softer but earlier which transfers more heat into the pad and disc and allows less time for them to cool before the next application. This was highlighted when the 996GT3 was first launched. A lot of drivers were complaining of overheating brakes but experienced drivers reported that they were fine. Porsche eventually asked a works driver to drive a complainants car to get to the bottom of it. I believe that the driver was Alan Mcnish. He did some very quick laps in the car with no problems. The owner jumped in and within a few laps he started to experience problems. Alan reported that the customers braking zone was almost twice as long and the brakes couldn’t cope with it. When the 996GT3 Gen 2 was launched the 4 pot fronts of the gen 1 were replaced with 6 pots.

Very impressive notes section mr Rance......
And a single seater man as well..
There are quite a few people who could benefit from this mans advice.
Fire more questions at him, and learn.
Cheers

Gadgit

[Wollemi]

Thanks for all the advice.

I'm really interested in what Steve Rance had to say; at the next track day I shall get instruction (as I always do) and look specifically at braking harder but
shorter.

It also seem like better cooling makes perfect sense. I'll get some GT3 cooling ducts, are there any disadvantages to having the GT3 ducts fitted? reduced ground clearance for example? Before the next track day I'm going to do the NC500 and go to Lewis & Harris too - so would it be better to delay fitting them until after that trip?

Edited by Wollemi on Tuesday 3rd April 12:06

[boxsey]

Wollemi said:

It also seem like better cooling makes perfect sense. I'll get some GT3 cooling ducts, are there any disadvantages to having the GT3 ducts fitted? reduced ground clearance for example? Before the next track day I'm going to do the NC500 and go to Lewis & Harris too - so would it be better to delay fitting them until after that trip?

Edited by Wollemi on Tuesday 3rd April 12:06

No downsides to the GT3 ducts. They're actually not much bigger than standard ducts. It's they're shaping and design that provides more airflow to cool the brakes. At about £9 each from an OPC I think they're actually cheaper than standard ones.

[Dr S]

Steve Rance said:

Your technique will make a big difference. An experienced track driver will brake late, very hard and come off of the brakes (or begin to bleed off) quickly. He or she will ask a lot from the brakes but for relatively short periods as it’s the method that will bring the quickest lap time. More inexperienced drivers tend to brake softer but earlier which transfers more heat into the pad and disc and allows less time for them to cool before the next application. This was highlighted when the 996GT3 was first launched. A lot of drivers were complaining of overheating brakes but experienced drivers reported that they were fine. Porsche eventually asked a works driver to drive a complainants car to get to the bottom of it. I believe that the driver was Alan Mcnish. He did some very quick laps in the car with no problems. The owner jumped in and within a few laps he started to experience problems. Alan reported that the customers braking zone was almost twice as long and the brakes couldn’t cope with it. When the 996GT3 Gen 2 was launched the 4 pot fronts of the gen 1 were replaced with 6 pots.

What he said. It is time and again surprising to see how much time less experienced drivers are spending on the brakes. Getting tuition is a very cheap way of solving the issue. Porsche brakes are designed to sustain proper usage.

It's different for e.g. the latest Audi TTRS. That car suffered brake failure on the Ring due to overheating in the hands Christian Gebhard, sport auto's head test driver and seasoned and pretty quick VLN racer. Here also the factory claimed that his braking technique was off. Well...