Brake failure at Mosport International Raceway June 6 & 7 2009

[syncros]

I'm back from a full weekend of track at the Mosport International Raceway and I must say that I'm very impressed by the way the car was handling all weekend long except for the brakes which failed big time in the first session where I started to push the car more (3rd run).

My track car setup is stock suspension with Toyo R888 tires with Carbotech XP12 on OEM rotors.

The brake-in for turn 5 is intense and slows you down from 160km/h to about 80km/h in a short distance as the car has a lot of grip has it climbs up a hill. As I pushed the brake harder on that section, I immediatly felt that my brakes were vibrating at the next braking section (turn 8 at the end of the long back straight). I hit 225Km/h on that straight and as I braked the steering wheel started to shake hard. I had to cope with this all weekend long and on Sunday the car was very tough to control under even light braking.

As I swapped my street wheels on on Sunday pm, you could feel that the brakes where not touching evenly the rotors as I was manually rotating the tires with the car up.

I'm real disapointed as everyone said to change the pads and the oil (which i did for Motul 600).

The vibration is so hard that I don't believe the issue is related to wrong pad material deposit on the rotors. The rotors seems warped. I haven't removed the backing plate but I will next time to help cool the brakes which don't any cooling ducts.

Anyone had similar problems with their rotors / brakes ? Lucid?

Thanks for your help, Vince

[lucid]

Did you bed-in the pads prior to the track day? I ran XP12s a few weeks ago at Lime Rock, and did not have any issues. I have gotten intermittent vibrations at times when using other pads and they all resolved after a few laps, so I think they were related to uneven pad deposits. I assume your rotors don't show any visible defects? Also, did you pull the pads out? How do the pad surfaces look? Are they worn evenly?

[DrKevM5]

Hello Vince! Sorry we didn't get a chance to meet. I had the exact same problem, as my pads were destroyed after the Friday Advanced session. To compound the problem at the first session on Sat., coming up the Andretti straight to #8 at 135mph, my car suddenly loses power and I get an error message that my fuel pump is defective!!! GAME OVER! Car goes into limp home mode, although later in the day it apparently reset itself. Luckily, I had two great students so the weekend wasn't a total loss. Bottom line, I will be going to a big brake kit, probably Stoptech. I am stunned that the stock brakes are worse than the ones on my previous e46. Compounding the problem is that there are no provisions for additional cooling (ducts), especially on the right side.

[von_zoom]

I changed rotors last year, and the first time on the track, after bedding had taken place, I noticed a little bit of shimmie coming from the front. The condition seems to worsen over the week end, so much that I did not run the last session. The next week we checked the rotors, and both had warped. Korman BMW who does my pampering, advised they thought the rotors were defected / bad and replaced them for me. I used the same pads (Hawk H10 Lucid) and I've had no problems since. I did however improve the air system for my brakes, replacing the old hose with a 1" larger duct.
vz

[attila]

I have the shimmie and some vibration (i even image or feel some nosie) from the front ever since I had severe issues with the stock pads. Since then I changed to the XP-10, bedded them, tracked the car (not too heavily, too many people on last session) but the issues are the same. Maybe less shimmie but same or similar vibration. I still dont think the rotors are warped, but is there any test one can do without taking them off??

I have some lines on my rotor from, minimal cobwebs etc.

This whole issue with the brakes is killing me. And I dont think Stoptech or Brembo would be better without cooling. At this point I am seriously considering getting a cheap car for track only. Like the new Z370 nismo.

[lucid]

Originally Posted by von_zoom

I changed rotors last year, and the first time on the track, after bedding had taken place, I noticed a little bit of shimmie coming from the front. The condition seems to worsen over the week end, so much that I did not run the last session. The next week we checked the rotors, and both had warped. Korman BMW who does my pampering, advised they thought the rotors were defected / bad and replaced them for me. I used the same pads (Hawk H10 Lucid) and I've had no problems since. I did however improve the air system for my brakes, replacing the old hose with a 1" larger duct.
vz

Just to clarify. Is your report based on your E92 M3 or your 5-series? Different beasts.

[von_zoom]

Just to clarify. Is your report based on your E92 M3 or your 5-series? Different beasts.

It is my 5 series - sorry, I should have made that plain. I have not tracked my E92 to any degree - yet. I was merely attempting to relate to the shimmie problem. I might add that I also tightened all the adjustment capabilities to my 525 shocks/suspension. I don't know if the shock set up on the E9X needs to be wrenched after track sessions, or if that can contribute to a shimmie situation.
vz

[Gearhead999s]

I am very suprised that you guys were having brake problems at Mosport.Mosport is my home track and over the years I have found it is by far the easiest track that I have been to on brakes.When I ran in the 24 hours twice in 91 & 92 in a E30 & a Camaro,we ran the same pads for the 24 hours and still had pad left in both cases.Mosport is totally a momentum track and the only place that you need to bleed off real speed is entering 5a.the rest of the corners are a maximum bleed off of 30mph even in a real fast car which does not create a lot of heat.My buddies who run real race cars running in the mid-20's usually blank off the cooling ducts to get enough brake temp as it is so undemanding on brakes there compared to the other tracks that we know.I ran about an hour with zero braking issues there last year on stock pads and had only a mild thumping that cleaned up in a weeks street driving and those pads were in the car for about 17000 kms on the street after that.

How did you bed in the pads?

Where you running with the MDM on as this will cause high brake temps even though the light is not flashing.

[attila]

Where you running with the MDM on as this will cause high brake temps even though the light is not flashing.[/QUOTE]


Very interesting thought!! Never thought about that, but I bet you are right! I did not have too much brake issues last time but the track was very busy I could not drive even close to the limit. So the XP-10 held up well.
I will turn DSC off completetly. I had the feeling last time that MDM was more of a hindrance than help with the BFG-Gforce1 tires.

[syncros]

I will dismantle the brakes tonight, take pictures and post them for you to see the actual situation. I'm thinking of removing the rotors, sand them on both side to remove any pad material and to reinstall them and to check if it does any difference. Otherwise I will put the OEM pads and will get them replaced by the dealer as I have the extended maintenance plan.

I'll keep you posted on the results and on the pictures of them.
But I still suspect that the rotors are warped as they rub only half way when I manually turn the wheels when on jacks and they squeel like hell even when I don't brake at slow speed.

[syncros]

Multiple answers below

Originally Posted by lucid

Did you bed-in the pads prior to the track day? I ran XP12s a few weeks ago at Lime Rock, and did not have any issues. I have gotten intermittent vibrations at times when using other pads and they all resolved after a few laps, so I think they were related to uneven pad deposits. I assume your rotors don't show any visible defects? Also, did you pull the pads out? How do the pad surfaces look? Are they worn evenly?

Lucid, I bed the pads in 3 days before the event on the street late at night on a "half-highway" where the limit if 60mph. (Although Carbotech recommendations is to bed the pads at the track) I followed some good instructions and ride the car about 300miles after to get to the track so the pads looked ok before my first session but the were squeeling like pigs!

My first 2 sessions went ok as I was discovering the track and not pushing the car at all.

The rotor don't show anything special other then a strong blueish color. I will pull out the pads tonight and post pictures. Thanks for your help.

Originally Posted by DrKevM3

Hello Vince! Sorry we didn't get a chance to meet. I had the exact same problem, as my pads were destroyed after the Friday Advanced session. To compound the problem at the first session on Sat., coming up the Andretti straight to #8 at 135mph, my car suddenly loses power and I get an error message that my fuel pump is defective!!! GAME OVER! Car goes into limp home mode, although later in the day it apparently reset itself. Luckily, I had two great students so the weekend wasn't a total loss. Bottom line, I will be going to a big brake kit, probably Stoptech. I am stunned that the stock brakes are worse than the ones on my previous e46. Compounding the problem is that there are no provisions for additional cooling (ducts), especially on the right side.

Hello DrKev, it would have been nice to discuss our brake issues at the track.
Were you using stock pads or did you have track pads? As I put Carbotech XP-12, I had high hopes to have a good weekend without braking issues as I don't consider myself an heavy braker and this track is easy on brakes.

Originally Posted by attila

I have the shimmie and some vibration (i even image or feel some nosie) from the front ever since I had severe issues with the stock pads. Since then I changed to the XP-10, bedded them, tracked the car (not too heavily, too many people on last session) but the issues are the same. Maybe less shimmie but same or similar vibration. I still dont think the rotors are warped, but is there any test one can do without taking them off??

I have some lines on my rotor from, minimal cobwebs etc.

This whole issue with the brakes is killing me. And I dont think Stoptech or Brembo would be better without cooling. At this point I am seriously considering getting a cheap car for track only. Like the new Z370 nismo.

I will remove the front rotors tonight to figure out it they look straight, but I don't have anything to check if they are straight. I will only sand them, but the oem pads on and see if they still vibrate.

Next time, I will remove the backing plate and I'm starting to wonder if we should had cooling ducts to our cars.

Originally Posted by Gearhead999s

I am very suprised that you guys were having brake problems at Mosport.Mosport is my home track and over the years I have found it is by far the easiest track that I have been to on brakes.When I ran in the 24 hours twice in 91 & 92 in a E30 & a Camaro,we ran the same pads for the 24 hours and still had pad left in both cases.Mosport is totally a momentum track and the only place that you need to bleed off real speed is entering 5a.the rest of the corners are a maximum bleed off of 30mph even in a real fast car which does not create a lot of heat.My buddies who run real race cars running in the mid-20's usually blank off the cooling ducts to get enough brake temp as it is so undemanding on brakes there compared to the other tracks that we know.I ran about an hour with zero braking issues there last year on stock pads and had only a mild thumping that cleaned up in a weeks street driving and those pads were in the car for about 17000 kms on the street after that.

How did you bed in the pads?

Where you running with the MDM on as this will cause high brake temps even though the light is not flashing.

My problem occured at the entry of turn 5 and i found that this required heavy braking. Since this was my first time in Mosport I overbraked at the entry of turn 8 as I was impressed by the 225-230Km/h at the end of the straight. Other then this, I agree that this is an easy track on brakes.

I was on DSC on the lap but not on MDM so only the rear brakes could have been affected. I bed the pads on the street where I did a sequence of heavy 60mph-10mph braking for 10 times and repeat the sequence after a 5 minutes brake cooling time (running on highway without ever touching the brakes.

Originally Posted by r53s65e90

I had a similar experience after a day at laguna seca with stock pads and rotors (both times). Towards the end of the day there was a vibration during braking that felt like warped rotors. Brakes worked fine so I didn't worry too much then and just thought that all I would need to do is change rotors and pads. Note that I was taking extra care of cooling down everything after a session. This included 5-10 min driving around the ring road.

Since then (1k+ mi later) my brakes are back to normal, so I am suspecting pad material deposits during the track day. Unless the vibration is really hard, I would say give it some time.

The vibration is bad according to me so I must take action before my next track event in a month as I don't this to happen again.

[Gearhead999s]

My problem occured at the entry of turn 5 and i found that this required heavy braking. Since this was my first time in Mosport I overbraked at the entry of turn 8 as I was impressed by the 225-230Km/h at the end of the straight. Other then this, I agree that this is an easy track on brakes.

I was on DSC on the lap but not on MDM so only the rear brakes could have been affected.




DSC & MDM uses all the wheel brakes to try to control the yaw not just the rear brakes.Hard braking at corner 8 is not sustained for very long as you trail brake into the apex.The best way to think of corner 8 is a turn on a oval that goes right.You carry a lot of speed right to the apex of 9 or at least try to!I have run stock pads on the last 3 cars that I have run at Mosport and never had any real issues and have been well into the mid 30's.Mosport is real easy on brakes.

[syncros]

You were right!
I removed the front wheel and realized that the front left wheel was tough to turn on without any brake applied to it. I removed the disks, lightly sand them and reinstalled the OEM pads and I must say that the vibration is almost all gone. I will double check and confirm tomorrow after a full day of driving the car. I'm just amazed at how much uneven pad deposit on the rotors can create such vibration.

Would I be better to have a set of dedicated rotors for track usage or should it be ok to use the same rotors with 2 types of pads? (I intend to track the car for about 10 days per year)

Thanks to you all, Vince

[jml]

I thought carbotech advised that you should not mix ceramic and carbon-metallic compounds? They are pretty explicit that you should run their pads on dedicated rotors - which I interpret as it being difficult to bed another type of pad material.

from their website:
"2. Do I have to resurface (turn) the rotors, or get new rotors?

If you have had another manufacturers brake pads on those same rotors; then you will ABSOLUTELY have to replace or resurface (turn) those rotors before installing the Carbotech brake pads.

If the rotors and drums are in relatively good condition, meaning they are smooth, flat, with no visible cracks, deep scoring, distorted, and with no other visible damage; and you have ONLY had Carbotech brake pads on them, then they do not have to be resurfaced or replaced. "

[lucid]

When I spoke with the Carbotech rep on the phone last year, he said their pads will work fine on an E9X rotor that has only been used with the stock pads.

[Subw00er]

Originally Posted by syncros

Multiple answers below

I bed the pads on the street where I did a sequence of heavy 60mph-10mph braking for 10 times and repeat the sequence after a 5 minutes brake cooling time (running on highway without ever touching the brakes.

It sounds to me like uneven pad wear. I think there may be two things going on. When you bed your pads, you say that above you did a second bed after 5 minutes of driving. Who told you to do this?! I bet this is what applied the material unevenly.

The second thing is that the xp12 is a VERY high temp pad and because you mention you are a light braker, it is possible that you are not getting enough heat into the pads. Keep in mind, this is a pad that professional racers might use.

I'd suggest you run your rotors with normal pads for a while to clean them up and wear off the material, then buy some xp10 pads and do a proper bed in and DONT bed a second time, especially that soon. Keep in mind there is a lot of metal down there, the rotor, hub, the wheel itself... It takes time to cool, and perhaps you cooled it only partly so when you when to bed in, you unevenly applied pad material to the rotor. You shouldn't need to bed a second time, I never have and I've been through about 5 sets of carbotechs in varying compounds (mostly xp10).

[von_zoom]

This may help. After new pads, I have used this proceedure, or something very simular, and have not had problems.

http://www.zeckhausen.com/bedding_in_brakes.htm

vz

[syncros]

VZ, I used these instructions which stated to bed the pads twice.

Lucid, I remember too that Danny from Carbotech mentionned the same to me. That they couldn't be used with other performance brake pads.

Today the vibration is better then yesterday with the OEM pads, but not gone yet.
I took an apointment at the dealer tomorrow because my differential seem to be leaking oil and I want this to be check as well. My visit to dealer will confirm our not the level our service that I will get under my extended maintenance program. I will never mention anything about this pas weekend and will see what they say about my front brakes.

My friend bought some XP10 and they indeed look better for this car, altough the sales rep of Carbotech strongly recommended the XP12 as our car is heavy. For the price difference I took the XP12 as per his recommendation.

I was told that Performance friction were offering the best pads and rotors on the E46 that you could use on the street and on the track. My instructor has this setup and after 3 heavy days of track no dust were to be seen on his aluminum wheels. James Clay posted yesterday that they should offer a similar package later on this summer. What do you think?

[Gearhead999s]

I have used PFC's in the past with very good results and look forward to the release of their product.I have Hawk HP +'s in the front of mine & have have experianced zero material transfer and they worked quite well on track with people telling me that the front rotors were glowing red braking down from the top of third gear.Had some fade but I am pretty sure that was from the stock rear pads as the Hawks were not available for rear as of yet.The noise on the street is another matter though and I think my street pads are going back in as soon as I have a chance.

[syncros]

Here's the result of the dealer investigation: Front rotors are warped by 0.006" while BMW replaces any rotor with more then 0.003" deviation. Rotors in order and covered by the extended maintenance plan. At the same time, they have order 2 seals for the differential. (both side leaking).

Do you any good recommendations to make sure that it won't happend again with the new rotors?

Thanks,

[jml]

Originally Posted by von_zoom

This may help. After new pads, I have used this proceedure, or something very simular, and have not had problems.

http://www.zeckhausen.com/bedding_in_brakes.htm

vz

Everyone, keep in mind that bedding in a race pad is a totally different level of effort. You will need to reach higher speeds, and get the pads up near their MOT slowly. For me, this takes at least 15 stops from 80-100mph to 50 with a 1400 degree MOT pad like the HT10.

PFC01s are the way to go when they are available. Far less sensitive to bedding in.

[DrKevM5]

Originally Posted by syncros

Here's the result of the dealer investigation: Front rotors are warped by 0.006" while BMW replaces any rotor with more then 0.003" deviation. Rotors in order and covered by the extended maintenance plan. At the same time, they have order 2 seals for the differential. (both side leaking).

Do you any good recommendations to make sure that it won't happend again with the new rotors?

Thanks,

Same issue for me, .05 mm left, .06mm right! Replaced under warranty. And I am ALWAYS careful with proper cool down after runs.