Cool Carbon Issues at the track this weekend??

[DriveHard]

At lime rock this past Saturday ( yes...right before the hurricane with about 35 other die-hards, 1 wet session 2 dry and 1 moist)


First of all i have the BMW BBK (so other than the crossdrilled / slotted rotors i am the same as a 135)
This was my second track day on the cool carbons, Third event on the BBK performance rotors..

Stock pads and BBK were fine... actually very good.. maybe a slight fade in the 5 session of the day.. ( historically speaking)

Cool carbons and BBK and Titanium shims (1st time out at NJMP) very good.. a little more rough feeling but no vibrations or issues.. Beeded in 1 week prior to event, and following all the guidelines etc

Cool Carbons and BBK and Titanium shims ( 2nd time out at Lime Rock park) ... 2nd lap after warm up lap, the steering wheel almost jumped out of my hand braking for big ben..!! that is not a place to not have brakes..!!.. I layed off for that lap and used the lap to see what i had.. on the 2 other turns where you will use brakes( but not as agressively as Big Ben) lesser vibration but working well..
as the laps went by held back a bit.. then let the session end.. I looked at them visuially and saw no high spots / or issues..

mind you they were absolutly great between events on the street while driving very spirited.. it was a month between events.

Next session,( 40 minutes later) i took it easy on first lap, and after being sure nothing was mechanically wrong, i laid into them as needed... and they were much better but still a minor vibration.......

after the third they were a little better than the 2nd session and never impoved from there..

conditions at track were 80deg's 1 wet session, 1 dry session, 1 moist session, and the last dry session..

Im almost 2 seconds off my best time at this track, and i blame the pads..its the only thing that held me back..

Are theses pads that sensative that they need to be bedded in befor each event ???? is the transfer layer that sensitive... did the brakes get better later in the session because they bedded in ( even though in a bad way)

driving to work today , i laid into them and the rotors seem fine ( no warping that i can tell)

any thoughts ??? I actuall felt the car was better with the stock pads ???

[pixelblue]

Alex,
I had vibration issues with my breaks too but I have noticed that cool carbons bite way harder when they get hot. I have to say been on CC since last year for a total of 7 track days and I have to change them now for my next event. I was debating if I want to try something else and I am leaning towards getting them again. I really can't complain about my breaks. haven't experienced too much fade, they bite pretty hard and has a great release and NO DUST! the pistons and the seals still look pristine, calipers are not discolored but need to replace the rotors for next year. I can promise you I am no slouch on the track yet not sure how some people get to destroy them so easily.

[DriveHard]

As it was just this weekend, i havent looked at pistons / seals.. I looked at them when i put them on and they looked great.. when i swapped tires.. rotors wer not discolored any more than they would normally, and calipers looked great.

ill try to look at them tomorrow in detail..

so am i correct in assuming it was transfer layer being reapplied????? do you bedd in before each event ??? does your vibrations subside during the course of the day ??

Thanks for your input

[pixelblue]

to be honest, I attempted to bed the pads twice but I am pretty sure I didn't do a good job. so difficult to find a long stretch of quite road around here. I must say the vibration is less noticeable this year compared to last partly because I have improved my breaking technique. your guess for the transfer layer would be a good one. I recently found micro cracks on my rotor which I am sure could cause vibration also.

[nordique14]

my first couple of laps out on the CC always give me some vibration but then they are fine the rest of the day. I get about 3 track days out of a set...and I am not punishing the brakes either. Not sure how anyone would get them to last 7 track days.

[GaryS]

I haven't noticed any vibration. They do bite harder after the first lap or two. My last set of front pads lasted 4 track days. The left side still looked pretty good, but the right side was gone.

[DriveHard]

Originally Posted by nordique14

my first couple of laps out on the CC always give me some vibration but then they are fine the rest of the day. I get about 3 track days out of a set...and I am not punishing the brakes either. Not sure how anyone would get them to last 7 track days.

Thanks .. and did you find that you needed to re bed them or did you only bed them in once when you first put them on?

7 track days = slow in, fast out >>>> read "smooth"

[pixelblue]

Originally Posted by DriveHard

7 track days = slow in, fast out >>>> read "smooth"

I don't know why I got so many track days out of them but trust me my times at this particular track is very fast. for example, a local pro driver in a stock E90 M3 participating in one lap of america was slower than me. granted I am running on R comps but still

[wkndracr]

I was also one of the nut jobs at Lime Rock this weekend, although I brought my Miata. I believe we chatted a little bit before the sessions started. I have the Cool Carbons on my 135i and I have the same issue. They are fine at normal street temps, but have a nasty vibration once up to track temps. I have 5 events on them and I first noticed it at my third event last year which was at Monticello.

I plan on bringing it to Lightning this weekend, so I decided to try to get them up to temp on the way home from work today to see if all the non-track miles evened it out a bit but the vibration did come back.

What I did notice last year was that it did get better after the first session, and is more pronounced if I'm not applying a lot of brake pressure. I noticed it the most while braking for the left hander at Lime Rock, to the point where it felt unsafe, but it did progressively get better later in the session, to the point where it was more of an annoyance than a safety issue.

I think I am going to either get a new set of rotors, depending on what I can get them for and if I can get them in time, or just pull them off and have them cut, and re-bed them. In my case I can see some spots on the rotors where it doesn't look even so I'm sure that is the issue.

[xerox445]

It sounds like the pads are changing shape at temp, or creating some type of boundry layer.

What type of rotors are you both running?

[wkndracr]

im running the stock rotors that came on the car. I didnt have too many miles on them before I changed pads, but I definitely didnt start with a fresh set. I just had the rotors cut and they said the fronts did have a slight wobble to them.

[wkndracr]

Just an update, I installed the freshly machined rotors and the vibration did come back, oddly enough. I can physically see uneven deposits on my right front rotor, so that must be the culprit. Its so hard to find an open road, to properly bed, but i did manage to get a bunch of stops on the NYS Thruway from 80-20 during bed in. Maybe I'm just not bedding in properly. I think I might just stop being cheap and get a set of new rotors and Carbotechs up front for track days. So frustrating. Looks like I'll be taking the Miata to the track this weekend.

[DriveHard]

Originally Posted by wkndracr

I was also one of the nut jobs at Lime Rock this weekend, although I brought my Miata. I believe we chatted a little bit before the sessions started. I have the Cool Carbons on my 135i and I have the same issue. They are fine at normal street temps, but have a nasty vibration once up to track temps. I have 5 events on them and I first noticed it at my third event last year which was at Monticello.

I plan on bringing it to Lightning this weekend, so I decided to try to get them up to temp on the way home from work today to see if all the non-track miles evened it out a bit but the vibration did come back.

What I did notice last year was that it did get better after the first session, and is more pronounced if I'm not applying a lot of brake pressure. I noticed it the most while braking for the left hander at Lime Rock, to the point where it felt unsafe, but it did progressively get better later in the session, to the point where it was more of an annoyance than a safety issue.

I think I am going to either get a new set of rotors, depending on what I can get them for and if I can get them in time, or just pull them off and have them cut, and re-bed them. In my case I can see some spots on the rotors where it doesn't look even so I'm sure that is the issue.

Hey wkndrcr.... Yeah it was me ( alex btw) that you chatted with..LOL.. how funny is that !! Ill be at Lightning also so ill see you there.. my buddy will have his s200, but my other friend with the 135 wont be comning..

Odd isnt it??? I was able to bed them in very well on the beach parkway at night ( ocean parkway by jones beach ) They felt great the next morning and at Lightning the following weekend... Thats why i was so supprised as to how they felt at limerock..

since limerock i bleed the brakes and checked for runout and they were fine..

The rotors although they have some slight groves that go allthe way around, they dont appear to have discoloration and or highspots.. BTW the groves are somewhat normal from what i see everyday in the shop..

I think i am just gonna bed them in again saturday night, and see hgow they are on sunday ( im not going for saturday event btw)

see you there i guess.. bright and early

[DriveHard]

Originally Posted by xerox445

It sounds like the pads are changing shape at temp, or creating some type of boundry layer.

What type of rotors are you both running?

My car is a 128 with the BMW BBK so i have the Vented and crossdrilled Rotors that come in the kit from BMW.. also the 6 piston Brembos..and i added the Titanium shims and ATE super Blue... the rotors never exhibited a pulsation before and that was 3 events with stock pads and now 2 events with the cool carbons. The rotors have about 8k on them ( maybe if that )

as of last night, they feel fine on my local "test track" i.e hard decel from 90+ to 50 / 40 mph... no vibration at all...

It must be a deposit issue... ????? i cant see anything else... i even checked all the bushings / strut mounts / tie rods etc .. they are all fine.. BTW the car only hass 11,5k on it..

[wkndracr]

Hey Alex, (I'm George btw) I guess I'll see you on Sunday! I'll have the Bimmer too . I ended up cleaning the deposits from the CC pads and put the stock pads back on. I did a few high speed stops the same way I did the other day, and I have no vibration! They definitely don't have the high temp grip the CCs have, but they're nice and smooth. I was able to get them hot enough that I could smell them, and they still stopped pretty well. We'll see how they hold up at Lightning. I guess the CCs are really hard to bed in, or my pads have been through too many heat cycles to be able to transfer material properly. The pad surface was a bit pitted and felt a little crumbly to me. Hard to explain, but I have a pic.

[xerox445]

You need at least 5 to 6 hard stops, getting progressivly faster each time to properly bed a pad in with a higher heat range. In my STI with porterfields, I did 60 to 10, 70, 70, 80, 85 all at "ABS threshold", (I made the girl in the car with me puke). Then drove for a few miles without touching the brakes to cool down. Never had an issue with them, lasted a long time, and always had crazy bite.

This was a street/strip compound.

[Elsabor67]

Good thing I ran into this thread. I have the CC pads front PowerSlot slotted rotors and steel braided lines from ECS tuning with ATE racing blue brake fluid. While at the 'ring last sunday I was experiencing the same things noted on this thread with the vibrations too. The more I pounded on the brakes the harder it felt but after mile 4 of the 12 it takes to do a lap they weren't as loud. I have 2 videos posted in the europe section and on the video of the second lap in some parts of the videos you can hear it.

The only concern I have is with the discoloration I sometimes see on the disc. I will try to take a pic later today with the car stopped and rotors cold. Should I really be worried about that or is it normal to see this? I still have the stock front rotors and plan on installing them after mid-oct once the weather gets colder. Any advice would be truly appreciated.

Nick

[wkndracr]

Discoloration on the disc is normal, as long as it is even around the disc. My discs had a bluish tint to them after the bed in procedure.

[DriveHard]

hey george..

wow those pads look a bit beat up more than i would have imagined... Imgonna try re bedding them in tonight and give it one last shot at Lightning. When i bed mine in the first time they were great like i said in an earlier post..odd i guess.. im prepping my car tonight so ill take a little closer look at them.

me and dan will be there at about 730ish ... come by and feel free to share the tent i bring.. at least well be out of the sun while the race is on after the first session, dont be a stranger..

if they dont do well, im gonna give cool carbon a call.. it just doesnt seem right, since alot of other peopel seem to really like them.

[DriveHard]

Originally Posted by Elsabor67

Good thing I ran into this thread. I have the CC pads front PowerSlot slotted rotors and steel braided lines from ECS tuning with ATE racing blue brake fluid. While at the 'ring last sunday I was experiencing the same things noted on this thread with the vibrations too. The more I pounded on the brakes the harder it felt but after mile 4 of the 12 it takes to do a lap they weren't as loud. I have 2 videos posted in the europe section and on the video of the second lap in some parts of the videos you can hear it.

The only concern I have is with the discoloration I sometimes see on the disc. I will try to take a pic later today with the car stopped and rotors cold. Should I really be worried about that or is it normal to see this? I still have the stock front rotors and plan on installing them after mid-oct once the weather gets colder. Any advice would be truly appreciated.

Nick

The blueish hue is normal.. thats a combo of the heat and transfer layer...

[DriveHard]

Just wanted to follow up on my issues with the cool carbons after a few track days...

Well I spent labor day weekend Sunday with my Racing Club (EMRA Eastern Motorsports Racing association emraracing.org) at beautiful NJMP Lightning course.. Wkndracr was also in attendance with his 135, along with his friend in his Miata, and my friend in his s2000.. Cudos to all as wkndracr pulled off a 1:20:xxx good enough for second, my buddy dan pulled a 1:21:xxx for third and i came in fourth with a 1:22:xxx, 2 seconds better then my best time there !!! ( and yes we are all in the same class ST-2 )

There are 2 big braking zones at lightning, and 2 moderate ones, the rest are all tap and go corners. I was hesitant to bring out the cool carbons again but when prepping my car the night before, i went over everything.. pads, shields, lines, lug nut torque, even checking rotor runout ( it was .0015 ) every thing looked fine.. i re-bedded the pads that night as best i could as it was laborday weekend and there were cops everywere, espically my special " lonely highway"

Im happy to say that i did not nearly experience the "shake the wheel out of my hand vibrations" pulsation this time out.. on the first warm up lap under double yellow, i just eased into the corners figuering i would just bring them up to temp and see how it went after the green flag..

Turn 1 braking zone gave me a slight vibration, no where near a pulsation that i felt at Lime rock the previous week. so i felt good for the rest of the braking zones.. The pulsation came back after a few laps, and then went away again to a small vibration. The rest of the day in the other sessions, it basically went the same way..

i suspect that after all the checking, that the vibration i get is mearly the result of that pad and my BMW BBK slotted and crossdrilled rotors.. and the Pulsation that i get is from random, temp related pad deposit..

I wish it werent there but it is manageable, and at least i know not to worry about it per-say..

The stopping performance was great by the way.. as a 128 automatic, i get up to about 120 to 125 ish ( indicated) at the end of the front straight, that is if i get the exit and acceleration i need out of turn 11 and when i tell you i lay into them for turn one, turn right, clip the curb, and track out at 60 to 70ish ( i think ) i have always felt good that i would never see the grass at the track out point..

Iguess what i am trying to say is that i dont think that the pads/ rotors would need re-bedding every time you go out, or have to worry about it when you do go out because by the time you find out, its too late.. there is no way to properly bed in brakes at the track because youll never have a cool off period.

I daily drive this car, and drive it in a spirited manner most of the time, so its not like my brakes dont get up to temp on a regular basis..

Hope this helps someone searching in the future, as i dont want to say cool carbons are bad, because they are not.. they just seem to have a personality that may not be for everyone..

if there are any question, feel free to ask.. ill keep looking at the thread.

Regards,

Alex.

[wkndracr]

Nice follow up. I meant to ask how the pads were doing, but we had so little time between sessions. My stock pads held up pretty well considering how hard I was on them, but the CCs definitely would have performed better. I still think they are a great choice if you want a dual purpose pad. I actually still have a little bit of vibration at street temps, probably because they have such a good initial bite when cold that the CCs don't. I'll guess I'll bring it in and see if I can get them replaced under warranty.

It was nice hanging with you guys this weekend. I do think its a little unfair to have the 135 and 128 in the same class. The extra torque the 135 has coming out of the corners really helps. The rear would get loose if I accelerated too much coming out of turn one. Dan has some serious car control. It looked like a lot of work to keep that s2000 pointed in the right direction. He seemed to be sideways at every corner, lol.