Took my S3 to the Track- What Did I Do to My Brakes?

[mikedb]

A few weekends ago, I took my S3 for a day of lapping with an instructor at my local track: http://www.calabogiemotorsports.com/ . It was incredible fun and the car performed very well. Both my instructor and I were really impressed with how it handled the 3.5 hours of hard track driving, while passing cars we had no business passing.

However, it is clear that the repeated braking from 200 km/h to 80km/h took a toll on my brakes. We didn't notice anything on the track, but on the drive home it was clear that they suffered some heavy wear. Not all that unsurprising, but I am hoping to get a little input on what needs to be replaced to get them back to near-new condition.

There are two main symptoms:
1- increased brake pedal travel- engagement is now much later in the pedal travel, but feels totally normal otherwise. After 1000kms of driving I don't really notice this anymore- not sure if that is because I have become used to it and need to bleed the brakes, or if the cause was pad wear that the callipers have adjusted to. Any thoughts?
2- The brakes sound quite a bit louder upon application (a low-frequency noise, almost 'humming'), and there is also pulsation. You can't really feel it through the pedal, but you can hear the pulsating noise. It sure sounds like glazed pads, but would those cause the pulsation as well?

If anyone has an idea what needs to be fixed/ bled/ replaced, it would be appreciated!

Thanks,
Mike

 

[S3Alex]

Even the 8V is a heavy car,and most of us with S3s have found that the brakes are quite poor for track use,and prone to overheat easily.

You may have got to the point where the pads have left deposits on the discs,and here is what mine looked like with an uprated brake kit(VWR) and DS2500 pads after a reasonably short time at Brands.




I think if you plan on doing trackdays that a decent big brake kit is the answer.

 

[cuke2u]

Warped discs?

 

[RO65ERS]

Sounds like you've ****** them aswell as the fluid!

 

[mikedb]

Thanks for all of your replies!

The track days will likely be no more than a few evenings a year, and for a car that I will only have for another 2-3 years, I think it would be a little overkill to upgrade the brakes. At this point, swapping out pads, rotors, and bleeding a bit of fluid from each calliper after a track evening or two is probably the more realistic solution.

I have driven ~1000km in the week since my track day, and assuming they are still safe, could come to live with the brakes in the shape they are in. That said, if there is a relatively simple process to get the brake pad deposition off of the brake rotors, it would fix most of my problem. Any suggestions for a method to do so? I could then bleed a bit of brake fluid from each caliper when I swap in my winter tires in two months.

 

[RO65ERS]

I would change the fluid, seeing as it's a simple and straight forward job.

Take the pads out and give them a good rub on some rough / sand paper. You may find they have glazed up so just rough them up and get the shine off.

Give the rotors a quick spray with some brake cleaner or even with the hose pipe. Let them dry and put the pads back in.

It'll all help.

 

[steeve]

Sounds very much like you've warped the discs, could be skimmed if they are not worn by a specialist or replace them and the fluid.

 

[A3_Rider]

Even a few hours driving on a track, depending on how you drive, can mean replacements. If you go to a track day expect to pay for new tyres and new pads. Even the clutch can go depending on how you drive. I wanted to go in my 8P but two new tyres + brakes + insurance just felt a waste of money.

 

[paulk]

my car did 4 laps back to back at the ring , only had a rear issues due to the queue getting off , but agree better fluid wouldn't hurt

 

[desertstorm]

If you don't do something with the brakes as they are now you won't be able to do another track day. You are likely to kill them completely if you tried to go on a track again. As stated above a change of brake fluid and bleed the system. A check of the brakes front and back to see what the pads and discs look like. A change of pad material may be a good idea to something more suited for track use.

 

[Bittern]

Did you have spongy brakes(long travel on the pedal and not braking) while going round ?. If so, that is the oil fluid was getting to hot and putting air into the system you will need a much higher boiling point fluid(DOT 4). Oh and changing to steel brake hoses helps as well(that's if you plan to do any more Trackdays that is ?). It sounds like your Disc's are warped because of the heat!. Jack the car up and spin the wheel, doing this will tell you if they are warped because you will hear it catching in a area of the disc(which in fact is a MOT failure).

 

[veeeight]

The standard S3 brakes (pads mainly) are not up to track work.

I get brake fade just from fast road work.

As @S3Alex says above, it's most likely deposits. See this:
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

 

[mikedb]

If you don't do something with the brakes as they are now you won't be able to do another track day. You are likely to kill them completely if you tried to go on a track again. As stated above a change of brake fluid and bleed the system. A check of the brakes front and back to see what the pads and discs look like. A change of pad material may be a good idea to something more suited for track use.

Well, I have to admit I did not follow this advice. I was at a corporate event at the track on Friday, and they surprised us by allowing us to bring our own cars out on the track during a later session. It ended up being me, a R8 V10, and a LFA out on the track for ~45 minutes- a little too sweet to turn down.

The brakes preformed without issue, and the 'warped' feeling and noise has actually gone away. This time I was very careful to take a full, slow cool-down lap, which I imagine helped significantly to prevent pad material deposition.

Did you have spongy brakes(long travel on the pedal and not braking) while going round ?. If so, that is the oil fluid was getting to hot and putting air into the system you will need a much higher boiling point fluid(DOT 4). Oh and changing to steel brake hoses helps as well(that's if you plan to do any more Trackdays that is ?). It sounds like your Disc's are warped because of the heat!. Jack the car up and spin the wheel, doing this will tell you if they are warped because you will hear it catching in a area of the disc(which in fact is a MOT failure).

The brakes never got spongy on the track itself- I actually only noticed the increased pedal travel on the drive home, when I could compare it to the previous travel under more normal braking conditions.

I would change the fluid, seeing as it's a simple and straight forward job.

Take the pads out and give them a good rub on some rough / sand paper. You may find they have glazed up so just rough them up and get the shine off.

Give the rotors a quick spray with some brake cleaner or even with the hose pipe. Let them dry and put the pads back in.

It'll all help.

I think this is my plan at this point. Since they longer have the 'warped' feeling/sound, I am pretty sure the rotors just need a clean. The only other issue to clear up is the long pedal travel, which I plan to address by sanding my brake pads, and bleeding the fluid that is in/ near the callipers in my front two wheels.

Does this sound reasonable?

Thanks,
Mike

 

[200sxr]

The brakes in most road car when used enthusiastically in the track will suffer. While going to a larger non floating caliper brake system with performance based pads will no doubt improve the performance of the brakes, here are a few things you can do to improve the performance of the stock setup.

1, Quality slotted rotors (not cross drilled)
2, Higher performance brake pads (you may want to consider a dedicated set for track use)
3, Change brake fluid before and after the event, use quality fluid

Lastly some people set the alignment before the track day and then set them back after the track day but it is up to you how serious you want to take it.

Cool down the brakes at the end of the session, do a cool down lap if possible; never park it straight after the session it will quickly cook the pads and fluid. Lastly do not use the hand brakes after the session.

 

[ACWKGYTO]

What brake pads and brake fluid would those in the know recommend that would improve the brakes for track and road use ?

Whilst keeping the S3 8V standard set up.

No brake squeel wanted though !