cobra rotors warping on road course events very easly
- Thread starter Robertp
- Start date
okay they are brembo rotors,
i measured run out on the brembos i have no clue which side they were on but on is 1.5 thousands the other is 4 thousands i suspect that the warped one is on the passenger side cause the drivers side napa one was about the same and the passenger side was 5 thousands whats your thougts guys, im thinking the hub is outta whack and from measuring the runout on it i think that also but i wanna here what others have to say, if its pad transfer id be suprised i tried my buzz wheel on the bad spots and i couldant change the reading on the rotors
Robert
i measured run out on the brembos i have no clue which side they were on but on is 1.5 thousands the other is 4 thousands i suspect that the warped one is on the passenger side cause the drivers side napa one was about the same and the passenger side was 5 thousands whats your thougts guys, im thinking the hub is outta whack and from measuring the runout on it i think that also but i wanna here what others have to say, if its pad transfer id be suprised i tried my buzz wheel on the bad spots and i couldant change the reading on the rotors
Robert
Robert,
I run CMP several times a year and it is hard on brakes. However, I have never warped a rotor on any of my cars. Not saying you haven't but just saying.
I'd suggest getting a new set of of Brembo OEM rotors (blanks) from Tire Rack and getting a set of Carbotech Bobcat brake pads and running that setup on the street for a few hundred miles. That will effectively slow season the rotors as suggested earlier. Then switch to a set of Carbotech XP10s (or XP12s) for the track.
The last set of rotors I had on my 99 Cobra (3685lbs) lasted two years with multiple trips each year to CMP by doing the above. I too would hit 120 before the Kink and 100+ on the front straight (running 1:51 laps).
And brake cooling is an absolute must on that track. More important than anywhere else. You have very little cool down time from T1 to T4 and very little from T14 to T1. Just over 2 miles with 14 turns; three of which are 90 degrees or greater and within less than a mile of each other.
-Kevin
I run CMP several times a year and it is hard on brakes. However, I have never warped a rotor on any of my cars. Not saying you haven't but just saying.
I'd suggest getting a new set of of Brembo OEM rotors (blanks) from Tire Rack and getting a set of Carbotech Bobcat brake pads and running that setup on the street for a few hundred miles. That will effectively slow season the rotors as suggested earlier. Then switch to a set of Carbotech XP10s (or XP12s) for the track.
The last set of rotors I had on my 99 Cobra (3685lbs) lasted two years with multiple trips each year to CMP by doing the above. I too would hit 120 before the Kink and 100+ on the front straight (running 1:51 laps).
And brake cooling is an absolute must on that track. More important than anywhere else. You have very little cool down time from T1 to T4 and very little from T14 to T1. Just over 2 miles with 14 turns; three of which are 90 degrees or greater and within less than a mile of each other.
-Kevin
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well what kinda power did you have to get those speeds, or u were prolly going thru turns much faster than i am at this point, thats pretty stout, im doing 120 between 7-8 also for a 99 cobra that couldant have been stock, the mach 1 the instructer guy had just had exhaust and he could do 108 lol i think he needs more power, well i ordered some hubs cause its funny how only one rotor out of 2 different brands would be warped and the runout on the one hub seems excessive to me at 6 thousands what you think?
Robert
Robert
Not sure about the runout... rotors and pads become disposables after a while and I have never bothered to measure one.
The 99 Cobra was not stock... it was putting 355/338 to the ground on a safe, reliable tune and a 3.55 gear (the most recent combination - the car had a long history).
-Kevin
The 99 Cobra was not stock... it was putting 355/338 to the ground on a safe, reliable tune and a 3.55 gear (the most recent combination - the car had a long history).
-Kevin
Yes, I warped all four rotors at Thunderbolt in NJ this past July. Very aggressive pads though - LOL.
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All motor. Here is the full list of parts on the car the last time I had it at CMP in June and turned the 1:51: http://www.svtperformance.com/forum.../637333-sale-1999-black-black-cobra-mods.html
When I had the blower on it several years ago, it was pushing anywhere from 480rwhp to 554rwhp depending on the tune.
BTW, I happen to have a set of front XP10s and rear XP10s for sale. Make me an offer if you are interested: http://www.svtperformance.com/forum...0-fs-carbotech-xp10-front-xp10-rear-pads.html
He's not warping the rotors, rotors hardly ever warp. He's getting uneven pad deposits on them, though, because the pads aren't being bedded-in properly. And those uneven deposits lead to hot spots on the rotor, which then turn into hard spots, which wear slower than the rest of the rotor, turning them into high spots, and the problem perpetuates itself.
The solution is 3-fold:
1) Put fresh, plain-faced rotors on the car, and season them before you take them to the track. Seasoning means gently adding heat to them, then letting them cool completely. This relieves internal stresses. Here's how: Baer Brake Systems | Performance you can See!
2) Get rid of the "Satisfied" pads and go with something more track-proven, like Carbotech XP8 or Porterfield R4, and bed them properly. This is the process of getting pad material to transfer evenly into the surface of the rotor.
Here's how: Baer Brake Systems | Performance you can See! or Instructions for bedding in your brakes
3) Add cooling ducts, and direct the air into the center of the rotor hat, not its inside face.
The solution is 3-fold:
1) Put fresh, plain-faced rotors on the car, and season them before you take them to the track. Seasoning means gently adding heat to them, then letting them cool completely. This relieves internal stresses. Here's how: Baer Brake Systems | Performance you can See!
2) Get rid of the "Satisfied" pads and go with something more track-proven, like Carbotech XP8 or Porterfield R4, and bed them properly. This is the process of getting pad material to transfer evenly into the surface of the rotor.
Here's how: Baer Brake Systems | Performance you can See! or Instructions for bedding in your brakes
3) Add cooling ducts, and direct the air into the center of the rotor hat, not its inside face.
^ I agree. It's just real hard to warp a rotor. 1500 degrees isn't going to do it and you are going to run out of pad before you get much hotter than that.
1:51 at CMP... that's um, pretty darn quick.
1:51 at CMP... that's um, pretty darn quick.
1.57 is the best I could pull so far but I'm running kumho mx tires not r compounds, I get alotta my time from the straight away speed iv got just need to brake a little later but with vibrations I wasent comfortable doing that
Robert
Robert
Runout is only part of the equation, and it's not even going to capture the bigger part of the equation, which is pad smear and the resulting hard spots on the rotor.
Read this, then do what I recommended above. The author of this article, Carroll Smith, was THE MAN when it came to suspension and brake dynamics and a whole host of other things involving racing. He very literally wrote the book. Several of them, in fact. http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml
You've got a lot of experienced people here telling you the same things: Season the rotors, get good pads, bed them properly, keep them cool.
As an aside, I wouldn't be worrying too much about lap times on your 2nd track day. There are better things to focus on, which will actually make your lap times quicker sooner.
.
Read this, then do what I recommended above. The author of this article, Carroll Smith, was THE MAN when it came to suspension and brake dynamics and a whole host of other things involving racing. He very literally wrote the book. Several of them, in fact. http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml
You've got a lot of experienced people here telling you the same things: Season the rotors, get good pads, bed them properly, keep them cool.
As an aside, I wouldn't be worrying too much about lap times on your 2nd track day. There are better things to focus on, which will actually make your lap times quicker sooner.
.
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Well i'm not to worried about lap times just some freinds timing me, well guys I understand about pad smearing, but I'm only having the trouble on one rotor the run out is in spec the other is not, that's why I think I have deeper problems than just pad smearing, also the run out is bad on both sides of the rotors, I'll definetly follow the bed in procedure, but when there is 6 thouthands run out on the hub that's a problem in my book, do u guys not think so??
Robert
Robert
Nm
well the bearings are tight but the run out in them is what bothers me well the run out in the passenger side one that is, the hubs are new but in 2000 are so cause i did a mustang lug pattern swap
Robert
Robert
Thanks, David. I thought it was so-so considering my competition that day. That was in Time Trials back in June. Temps were well into the 90's that day and I was on a well used set of NT01s.
BTW, you probably don't want to know that a couple of weeks ago I ran a 1.49 on six year old 25k mile original F1 street tires in the bone stock 03 Z06... in traffic.
No. no I don't.
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I just looked at my 2006 times....1:59. Even the GT-1 cars were only turning 1:51 race laps. Is the new configuration that much faster or is it just great driving. ;-)
MYLAPS
MYLAPS
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