Brake failure at the race track

[Gt86Force]

Originally Posted by Tristor

I started with Ferodo DS2500, and they are just not suitable for any serious track use. They are fine for a beginner who is doing occasional track days and primarily daily driving, they are not suitable for serious track use at all.

I don't want to be that guy, but based on some of the advice in this thread, it's really important to note that for critical safety systems you should be careful about making recommendations. Just because something worked for you does not mean it will work well for everyone, and most importantly, faster drivers are harder on critical subsystems. If you are finding the DS2500 (and RBF600 for that matter) sufficient on track, no offense but you're a slow driver. Neither of these are suitable for hard use.

I think it was Terry Fair that made the point that you should compare your laptimes on your preferred local track to what Spec Miata folks are doing on average. If you aren't beating the Spec Miata average lap time, you're slow and your experiences may not be suitable to extrapolate to someone else who is using their car harder than you are.

I agree, but I think also the OP is a starter (not recognizing brake fade is a beggineer mistake). BTW is not criticising, we all have been/are there! You need seat time and mistakes to learn!

The great thing with this platform is that you can start to approach the track with the car almost stock. Pads, oil, brake lines and tires and you are good to go IMHO.
If you can pace yourself, this car gives you the opportunity to learn a lot because is simple and really communicative. If you start with slicks, bbk, more power ecc. ecc. ignoring the fact that it may be dangerous, a lot of the root causes of your mistakes are not clear. (wrong braking technique for example).

I've started with that config, and upgraded when it stopped being enough. Now i'm running 265,ap racing (made by a company named essex, btw if you don't know them check out their website!! great products), more power, cooling ecc. ecc. It is a journey as it should be for every car you track independently of your experience.

And yes I'm slow driver, no offense! taken
I still pay for my track days, cars, mods, tires and gas. When you are fast usually you are getting payed.

[biggie]

Short review of the new setup (Stoptech slotted rotors, Carbotech XP10 pads - front only - Stoptech brake lines all around and same Castrol SRF).

During the pad's bed-in period the squealing was unbearable. This process took quite a long time, up to 600 miles of mixed driving (20% city, the rest up in the mountains).
Now, after more than 1k miles it seems to be a bit less noisy and I hope that's the case because they are bedded in properly and not because the outside temps have dropped in the last 2 weeks.
Up the mountains they behave great, lot's more feedback, no issues whatsoever.

On the track however there's an obvious tendency on straight hard braking for the back to slide around quite a lot. This was not the case before and my guess is because of the different pads in the back (yellowstuff). Also, the difference in feedback is not obvious on hard braking (and this is the case on most corners). Maybe there should not be any difference or I'm still to new in this and unable to see it, or maybe I did not pushed them hard enough for the difference to became obvious. Lap times are on par with those from my last trackday so I'm a bit disappointed. Ar least I'm more confident in my brakes.

I'll keep the pads for now, but I think I'll try something different next time (mostly because of the noise). Next on my list were Club Racer and DTC-60, does anyone know how these compare (noise wise) with XP10?

P.S. worth mentioning is that this time I did some cooling laps every 5 minutes or so

[new2subaru]

Originally Posted by biggie

Short review of the new setup (Stoptech slotted rotors, Carbotech XP10 pads - front only - Stoptech brake lines all around and same Castrol SRF).

During the pad's bed-in period the squealing was unbearable. This process took quite a long time, up to 600 miles of mixed driving (20% city, the rest up in the mountains).
Now, after more than 1k miles it seems to be a bit less noisy and I hope that's the case because they are bedded in properly and not because the outside temps have dropped in the last 2 weeks.
Up the mountains they behave great, lot's more feedback, no issues whatsoever.

On the track however there's an obvious tendency on straight hard braking for the back to slide around quite a lot. This was not the case before and my guess is because of the different pads in the back (yellowstuff). Also, the difference in feedback is not obvious on hard braking (and this is the case on most corners). Maybe there should not be any difference or I'm still to new in this and unable to see it, or maybe I did not pushed them hard enough for the difference to became obvious. Lap times are on par with those from my last trackday so I'm a bit disappointed. Ar least I'm more confident in my brakes.

I'll keep the pads for now, but I think I'll try something different next time (mostly because of the noise). Next on my list were Club Racer and DTC-60, does anyone know how these compare (noise wise) with XP10?

P.S. worth mentioning is that this time I did some cooling laps every 5 minutes or so

It doesn’t sound like you’re bedding the pads properly prior to using them. Driving 600 miles has nothing to do with it.

Look up bedding track brake pads.

[churchx]

+1. Track pads have high working temps. Normal daily driving rarely heat them up to those. If anything, one of main reasons for many track pads to squeal is for daily driving light braking pattern to wear down bedded layer from rotors in few days, thus asking for rebedding from time to time if one chooses using track pads all the time.

[norcalpb]

Normal street pads you would drive a ton of miles and they naturally bed themselves.

Track pads you need to be quite the lunatic but it only takes 10 min.

Accelerate to 60mph in 2nd gear. Slam on the brakes with 70% force until you slow down to 10mph. Do this 5 times in a row. Yes you will look like a crazy person so do this somewhere private. DO NOT come to a full stop as this may damage your rotors. Make a U turn on the road you were on and do the same thing but at 100% braking force (do not engage ABS as this’ll fuck it up too). Once you’ve done your 5 100% braking force 60-10mph brake runs drive around for 20 min (no full stops) to let the brakes properly cool.

I say 5 times as a general guideline as this depends entirely on your brake compound and tires. 200tw tires get the brakes to proper temp quickly when braking hard, but it may take more than 5 brake runs with a true track pad.

I like to do it until I can smell the brakes. Sometimes you can see sparks shoot out which is normal.

[churchx]

And now some eye candy instead of text
[ame]https://www.youtube.com/watch?v=pdPX6rzuINc[/ame]

[norcalpb]

I find it hilarious that race tracks say absolutely no bedding on track. So where do they expect you to do it without the risk of getting pulled over??

[NoHaveMSG]

Originally Posted by norcalpb

I find it hilarious that race tracks say absolutely no bedding on track. So where do they expect you to do it without the risk of getting pulled over??

I have some pretty good roads out here for it. Of course we are not nearly as populated.

[churchx]

BTW, regarding brake bedding topic - why not keep pressing accelerator simultaneously while braking? In most cars brake torque is way more then engine torque, and it will still slow down, also engine torque = less chance to lock up brakes, shouldn't it ease putting same amount of heat vs just braking in fewer iterations of slowdowns and from lesser top speeds? Or how about floored accel pedal at low gear to maximize torque, and mid-brake just about for constant speed .. shouldn't it also continuously just build up more and more heat in single cycle? Anybody know of possible illeffects of using engine torque during bedding, why such way is not mentioned in most bedding instructions?

[wparsons]

Originally Posted by norcalpb

I find it hilarious that race tracks say absolutely no bedding on track.

Unpredictable braking down to slow speeds will cause a crash in a HUGE hurry on a track.

Originally Posted by norcalpb

So where do they expect you to do it without the risk of getting pulled over??

In the paddock, or on a brake dyno (you can buy pre-bedded rotors/pads from race shops).

[strat61caster]

no need to overstress the drivetrain since brake pads for racecars go on racecars that may have powertrains that aren't super durable

Also many modern ECU's cut power when brake and gas are applied simultaneously due to the Prius accidents like 15 years ago, it wouldn't be possible on a lot cars.

Also @biggie get XP10's for the rear as well, it will totally fix the instability, and agreed that you didn't properly bed them in until you started doing laps. Yes they don't feel radically different but you should be able to use them harder and longer than what you had before.

[NoHaveMSG]

Originally Posted by churchx

BTW, regarding brake bedding topic - why not keep pressing accelerator simultaneously while braking? In most cars brake torque is way more then engine torque, and it will still slow down, also engine torque = less chance to lock up brakes, shouldn't it ease putting same amount of heat vs just braking in fewer iterations of slowdowns and from lesser top speeds? Or how about floored accel pedal at low gear to maximize torque, and mid-brake just about for constant speed .. shouldn't it also continuously just build up more and more heat in single cycle? Anybody know of possible illeffects of using engine torque during bedding, why such way is not mentioned in most bedding instructions?

All bedding instructions I have read say not to do that. No reason is given though.

[RFB]

Originally Posted by NoHaveMSG

All bedding instructions I have read say not to do that. No reason is given though.

Korporate Kash k-ching probably, doing it their way probably wears out the pads faster breaking them in their way. More money for Kommie Korporate swine.

[NoHaveMSG]

Originally Posted by RFB

Korporate Kash k-ching probably, doing it their way probably wears out the pads faster breaking them in their way. More money for Kommie Korporate swine.

That makes no sense but okay.

If I had to guess, dragging the brakes may create too much heat in the rotors to develop a transfer layer, but I dunno