Track brakes: rebuild & add cooling... or upgrade?

[odj]

Hi All -

I'll try to keep this as short as possible

I've been tracking my 135 for a bit, and have ended up with the following setup, trying to mitigate brake fade:

Stock calipers/rotors
PFC 08 pads F/R
Ti shims
F30 backing plates
RBF600 fluid

After adding wider wheels up front, the slight increase in cooling the F30 shields provided is null, and I can't bend them out to catch the air stream without them rubbing on something.

I inspected the calipers today (I have another issue with one of them) and all of the piston seals are fried. Crusty and toasty.

Anyways, I have a few questions for you all:

Do I drop the coin and rebuild both calipers, and add brake cooling ducts to the car?

Or do I invest in a BBK (such as stoptech)?

Which BBKs are actually going to be effective on the track and not just bling?

If I upgrade to a BBK, can I do just the fronts? Is it *really* going to screw up my proportioning?

If I upgrade to a BBK, will that solve my brake fade issues? Or will they require additional cooling as well?

Any input is appreciated.

[Ginger_Extract]

- I used RacingBrake SS piston rebuild kit for my OEM calipers, much better at resisting fade on track.
- Still going to build ducts, for increased cooling capacity. our cars are heavy.
- BBK's are all function, wider/bigger rotors, better caliper venting/cooling, etc.
- Just the fronts is fine, moderns automatically bias brake force, brake pad selection has bigger impact on braking effectiveness. Going with too much pad up front versus rear means more likely to lock up fronts and not get everything from the rears.
- Fronts do most the braking, so upgrading should fix all brake issues, but ducting can only be beneficial.

[Pyrat 2]

I have to say that if you are tracking your car and have lost confidence in your brakes then the bbk is the way to go. I installed a stoptech kit and I only wish I did it a year earlier. I have absolute confidence in my brakes now. No fade, more brake than tire, unbelievable.

If you can spring for the $s you won't regret it.

http://www.1addicts.com/forums/showp...5&postcount=42

[wjk_glynn]

I also got the StopTech ST60 BBK (specifically the version with the black calipers with 355x32mm rotors, p/n 83.165.6700.51) as they've got the correct brake bias for the 135i.

There is no question they have significantly more thermal capacity than the stock brakes (as evidenced by your toasted pistons).

However, I've one small gripe with the StopTechs in that I sometimes experience a small amount of variability in brake pedal travel/pressure from application to application: http://www.1addicts.com/forums/showt...2#post17568372

Most others with the ST60 do not report this problem.

If anyone has ideas on my niggly problem, I'm all ears...

Karl.

[2PUTT]

do you check your brake temps after your sessions? do you notice if you are trail braking? if so, this might be causing the extra temps on your calipers/rotors. the track used is also a factor to temps. some tracks can be brake intensive than others. i don't think BBK will help you.

the car already has 6pot brembos. the BBK will add rotor size which will help a little with temps. my suggestion would be rebuild the calipers. if you haven't switched to the better pistons, i would include this with the rebuild (http://www.turnermotorsport.com/p-11...-e82-135i.aspx).

maybe try different fluid as well. may i suggest Castrol SRF. this has a much higher wet boiling point than most fluids out there. Motul RBF600

i tracked my previous cars (a variety of Audi S4s) with StopTechs. i am pretty new to the 135. i was pretty impressed with the stock calipers in my limited time (1 event/4 sessions) with the 135. i basically used SRF fluid and Porterfield R4 pads. i believe that these are plenty for the car.

best of luck...keep us updated.

[Pyrat 2]

I have heard a couple others report this but haven't had the problem. I'm running st60s in front and st40s in back. I don't know if that makes a difference. I did a full bleed when installing earlier this year. Outboard bleed and then inboard bleed on each caliper. Pr, dr, pf, df in that order. Also, I do a mini bleed of just a couple ounces on each valve after each track event. Btw I run rbf600.

[Ginger_Extract]

Originally Posted by wjk_glynn

However, I've one small gripe with the StopTechs in that I sometimes experience a small amount of variability in brake pedal travel/pressure from application to application: http://www.1addicts.com/forums/showt...2#post17568372

Most others with the ST60 do not report this problem.

If anyone has ideas on my niggly problem, I'm all ears...

Karl.

- I have the same issue with stock calipers. Have bled brakes over and over again, and rebuilt calipers after they pistons blew out, issue still persists. Oh well. Doesn't affect brake performance enough for me to care.

[odj]

Thanks for all of the input guys. I know I'm asking for absolute answers on something that can vary widely per person per car per track, but I'm trying to at least make an informed decision before pulling the $$$ trigger.

Originally Posted by 2PUTT

do you check your brake temps after your sessions? do you notice if you are trail braking? if so, this might be causing the extra temps on your calipers/rotors. the track used is also a factor to temps. some tracks can be brake intensive than others. i don't think BBK will help you.

the car already has 6pot brembos. the BBK will add rotor size which will help a little with temps. my suggestion would be rebuild the calipers. if you haven't switched to the better pistons, i would include this with the rebuild (http://www.turnermotorsport.com/p-11...-e82-135i.aspx).

maybe try different fluid as well. may i suggest Castrol SRF. this has a much higher wet boiling point than most fluids out there. Motul RBF600

i tracked my previous cars (a variety of Audi S4s) with StopTechs. i am pretty new to the 135. i was pretty impressed with the stock calipers in my limited time (1 event/4 sessions) with the 135. i basically used SRF fluid and Porterfield R4 pads. i believe that these are plenty for the car.

best of luck...keep us updated.

I put some color changing paint on the edge of the rotors, and if I'm interpreting the color correctly, the front rotors passed 1400 degrees F.

I haven't been trail braking... trying to keep my braking zones short and intense (like with my prior car on the track).

[odj]

Well, after some more reading and speaking with Harold at HPA, I ended up pulling the trigger on the ST-60 based Stoptech kit, and ordered a set of SR34 pads for the track. Let's see how this works out...

[Pig Farmer]

Originally Posted by wjk_glynn

I also got the StopTech ST60 BBK (specifically the version with the black calipers with 355x32mm rotors, p/n 83.165.6700.51) as they've got the correct brake bias for the 135i.

There is no question they have significantly more thermal capacity than the stock brakes (as evidenced by your toasted pistons).

However, I've one small gripe with the StopTechs in that I sometimes experience a small amount of variability in brake pedal travel/pressure from application to application: http://www.1addicts.com/forums/showt...2#post17568372

Most others with the ST60 do not report this problem.

If anyone has ideas on my niggly problem, I'm all ears...

Karl.

Do you know if your shop used a pressure bleeder, or the old fashion two man approach (i.e. Pump up the brakes, open and close the bleeder, etc.). I had the same symptoms the first time I used a pressure bleeder with my stoptechs. Doing the two person approach (with the engine running) helped tremendously. I'd say I was 98% happy with the result. They I uninstalled and reinstalled my Cobb tune. When doing this, the Cobb seems to cycle every pump on the car (i.e. water pump, fuel pump, ABS pump). After that, the brakes have been rock solid. The fix may be as simple as having the ABS pump cycled to make sure no air is trapped in there.

[Ginger_Extract]

Originally Posted by Pig Farmer

Do you know if your shop used a pressure bleeder, or the old fashion two man approach (i.e. Pump up the brakes, open and close the bleeder, etc.). I had the same symptoms the first time I used a pressure bleeder with my stoptechs. Doing the two person approach (with the engine running) helped tremendously. I'd say I was 98% happy with the result. They I uninstalled and reinstalled my Cobb tune. When doing this, the Cobb seems to cycle every pump on the car (i.e. water pump, fuel pump, ABS pump). After that, the brakes have been rock solid. The fix may be as simple as having the ABS pump cycled to make sure no air is trapped in there.

You're a mind reader. This was my last guess as to the issue. I've done pressure bleeding and two-man old school bleeding. I'm guessing that a few little bubbles are trapped in the ABS/DSC module and only want to come out when coaxed enough.

[odj]

Originally Posted by Ginger_Extract

You're a mind reader. This was my last guess as to the issue. I've done pressure bleeding and two-man old school bleeding. I'm guessing that a few little bubbles are trapped in the ABS/DSC module and only want to come out when coaxed enough.

I've experienced the same thing. Never happy with my pressure or two-man bleeds. I had stumbled across a post that mentioned using INPA and a DCAN cable to cycle the ABS unit. I have to look into that further.... have a cable I bought a couple of years ago to reprogram some functions in my wife's MINI.

[wjk_glynn]

Originally Posted by Pig Farmer

Do you know if your shop used a pressure bleeder, or the old fashion two man approach... The fix may be as simple as having the ABS pump cycled to make sure no air is trapped in there.

I don't know, but if I can think of a way to cycle the ABS pump I will.

Karl.

[wjk_glynn]

Originally Posted by odj

...I had stumbled across a post that mentioned using INPA and a DCAN cable to cycle the ABS unit. I have to look into that further...

If you manage to dig it up, please share.

Thanks.

Karl.

[odj]

Originally Posted by wjk_glynn

If you manage to dig it up, please share.

Thanks.

Karl.

Karl -

Here it is:
http://www.e90post.com/forums/showthread.php?t=598994

I'm going to try and go through the process with mine, I just need to figure out which software and datens I need for the e82. It was trial and error getting the MINIs coded a couple of years back, so it might take me a bit. Will report back when I figure it out.

[Bullitt]

Originally Posted by wjk_glynn

I don't know, but if I can think of a way to cycle the ABS pump I will.

Karl.

I personally have not tried nor verified the following procedure yet, but it seems to have worked for a fellow member who accidentally ran his brake system dry and needed to bleed the ABS system:

"Put it up on 4 jack stands and drive the car in gear. Do not turn off traction control or anything. The car will not go above 15 mph and you'll hear the abs pump cycle. (The car will sound really weird) Once you do like 5 "pulls" for approx 10-12 seconds each pull, rebleed the brakes in the proper bleeding order. I did the whole cycle 3 times. It worked for me and I have my pedal back no problem."

Reference: http://www.1addicts.com/forums/showp...0&postcount=36

[wjk_glynn]

Originally Posted by odj

Here it is...

Thanks, and sorry for hijacking your thread!

Originally Posted by Bullitt

I personally have not tried nor verified the following procedure yet...

Interesting and thanks.

Though I'm the kinda guy people find under a collapsed car with feet twitching...

Karl.

[odj]

Originally Posted by Bullitt

"Put it up on 4 jack stands and drive the car in gear. Do not turn off traction control or anything. The car will not go above 15 mph and you'll hear the abs pump cycle. (The car will sound really weird) Once you do like 5 "pulls" for approx 10-12 seconds each pull, rebleed the brakes in the proper bleeding order. I did the whole cycle 3 times. It worked for me and I have my pedal back no problem."

Well, that sounds super sketchy

[odj]

Originally Posted by wjk_glynn

Thanks, and sorry for hijacking your thread!

No worries at all. That less-than-factory pedal feel had been driving me nuts.

[Pyrat 2]

Originally Posted by odj

Well, after some more reading and speaking with Harold at HPA, I ended up pulling the trigger on the ST-60 based Stoptech kit, and ordered a set of SR34 pads for the track. Let's see how this works out...

Nice. You won't regret it. I'm running Ferodo DS2500 at the track with my stop tech ST60/ST40 combo. Do be aware that if you run too aggressive of a pad you will overwhelm the tires and have ABS kicking in more often than you would like. It's a difficult dance to balance. I'm running MPSS at the track and the street and the DS2500s seem to be slightly more aggressive than I'd like for this tire. Not enough so though that I'm going to experiment too much as racing pads are $$$s and I think this combo is paired close enough.

Bottom line is don't get too aggressive a pad unless you have tires to handle it. You need to be pairing them in consideration of each other.

[odj]

Originally Posted by HeelToe

Nice. You won't regret it. I'm running Ferodo DS2500 at the track with my stop tech ST60/ST40 combo. Do be aware that if you run too aggressive of a pad you will overwhelm the tires and have ABS kicking in more often than you would like. It's a difficult dance to balance. I'm running MPSS at the track and the street and the DS2500s seem to be slightly more aggressive than I'd like for this tire. Not enough so though that I'm going to experiment too much as racing pads are $$$s and I think this combo is paired close enough.

Bottom line is don't get too aggressive a pad unless you have tires to handle it. You need to be pairing them in consideration of each other.

Point taken. I'm running ZII Star Specs, so hopefully they'll be grippy enough to balance out the stopping power. If not, it'll just be something new to learn, I suppose.

[odj]

Well, the brakes are on, bled, and bedded. Even with the street pads, they're already enough to lock up the front 225 ZIIs.

Gotta screw around with INPA this afternoon to see if I can cycle ABS. I did hit ABS a couple times when bedding the pads, and pedal was noticeably softer after doing so.