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Brake rotor failure

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I had an interesting experience yesterday and was wondering if anyone else has had a similar issue.. I bought a "track day kit" from powerstop off of american muscle with rotors/pads, and on my 4th session of the day I experienced total rotor failure. This was my first track day on these rotors, I had them on the street for a little while until I realized how aggressive the pads actually were... Anyways, this happened going into turn 7 at sears point.. Had it happened going into 11 I would have surely wrecked my car, luckily I was able to just drive straight off the track.

Now I am pretty worried about running any sort of 1 piece rotor.. Any thoughts?? I am planning on adding some cooling or I think a 2 piece rotor will help a lot..

Looking at the pic, it is apparent that the rotor got really hot.. Need to remember that I had zero cool down though, I pulled straight off track from heavy braking and then the car sat there.. Previous sessions the rotors didn't look as abused.

IMG_20200801_172825.jpg
 
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I had an interesting experience yesterday and was wondering if anyone else has had a similar issue.. I bought a "track day kit" from powerstop off of american muscle with rotors/pads, and on my 4th session of the day I experienced total rotor failure. This was my first track day on these rotors, I had them on the street for a little while until I realized how aggressive the pads actually were... Anyways, this happened going into turn 7 at sears point.. Had it happened going into 11 I would have surely wrecked my car, luckily I was able to just drive straight off the track.

Now I am pretty worried about running any sort of 1 piece rotor.. Any thoughts?? I am planning on adding some cooling or I think a 2 piece rotor will help a lot..

Looking at the pic, it is apparent that the rotor got really hot.. Need to remember that I had zero cool down though, I pulled straight off track from heavy braking and then the car sat there.. Previous sessions the rotors didn't look as abused.

What year is the car and what calipers are on it? From the pic it looks like you’re in an S550, but a few more details will help. No rotor should come apart like that, and is certainly not a trait or weakness of all 1 piece rotors.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
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Unreal Batman, never seen anything like that with any rotors, even though I have destroyed a few ( cracks ). I would be getting a set of two piece Girodiscs after that, as you probably need an aggressive pad at Sears Point , but you need some serious reassurance too. Check with KNS Brakes or Optimum Performance on this site and ask them about this --- spooky!!
 

TMSBOSS

Spending my pension on car parts and track fees.
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Did the pads wear evenly?? The reason I ask is to help find a possible cause, like a caliper out of alignment, stuck piston etc..

More likely a bad rotor.

Bill pushed Girodisc rotors, for good reason. They do cost more....sort of. Giros last the longest by far. I have never heard of a failure with a Giro.

The disc above, definitely a wall hanger for your garage.
 
Did the pads wear evenly?? The reason I ask is to help find a possible cause, like a caliper out of alignment, stuck piston etc..

More likely a bad rotor.

Bill pushed Girodisc rotors, for good reason. They do cost more....sort of. Giros last the longest by far. I have never heard of a failure with a Giro.

The disc above, definitely a wall hanger for your garage.
The pads appeared to be pretty even. I need to give them a better lock. I just made sure the wheel bearings did not seem sloppy and I just slapped another rotor on and limped the car home... At this point i probably will just get the giro disc setup for track use... Whats everyone like using for track pads?
 
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I have run the Power Stop Track Day pads on my S197 and they are very impressive for their price. However, I never used the PS rotors since their original rotors were drilled & slotted and NOT high carbon. From the description for these at:
https://www.americanmuscle.com/power-stop-mustang-track-day-brake-rotor-pad-kit-front-tdbk6811.html

it does not state the rotors are high-carbon iron. This may have something to do with it.

I have always used the StopTech (made by Centric) 1pc Slotted Rotors that are made with high-carbon iron. Never had a problem.

The only other thing I can think of is that one side of the rotors either heated or got cooled more than the other side and this caused warping that resulted in the catastrophic failure. What type of brake ducting do you have, if any?
 

Bill Pemberton

0ld Ford Automotive Racing Terror
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Noticed you have been doing HPDEs for 10-20 years so will assume you might be pretty aggressive with your brakes , but am referencing your pad use and not the rotor failure. There is no real excuse for that , but the big plus is Girodisc two piece rotors are US Steel , whereas most of the rotors out there are sourced elsewhere. Since we are not sure what your braking style is like or everything modded on your car , why not call KNS brakes or Optimum Performance and get their professional advice. They both carry Girodisc and though they are pricey they are less than their contemporaries and as noted they use steel made here -----many of the big names do not. I use G-Loc pads , but there are other good pads out there and I would definitely contact whomever you go the rotors from , especially the company and request they look at the rotor and ask what coverage they have for something like this?
 
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I've seen a failure like this before, but it was a two-piece front rotor on an FR500C. The mounting ears on the friction ring broke off and mangled the hat although the caliper survived. I'm not sure what the ultimate diagnosis was, but I suspect it was a combination of high heat and some kind of misalignment. The friction ring wasn't a Brembo ring, but I don't remember who made it. It was a reputable manufacturer - I remember that much - but which one, I won't speculate.

As for Girodisc, they're a great bunch of guys - I put a set of their front rotors on my 2011 Mustang GT, and I just dropped by their factory and picked them up on my way to the track. Good product, good people.
 

steveespo

Lord knows I'm a Voodoo Child
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Run Ford rotors. Or GiroDisc for OEM calipers, or upgrade to race spec stuff from AP, Brembo or Performance Friction. The rest of the aftermarket stuff is just cheap Chinese metal. If you are tracking any car, top quality brake parts are a priority.
 
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I've only ever seen this 1 time, the pads were either the wrong ones, or were installed incorrectly and they basically machined the rotor off it's hub.. assuming all is well with that, I would def be calling powerstop and asking them for new parts.
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
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I bought a "track day kit" from powerstop off of american muscle with rotors/pads,

Actually, go right back to American Muscle as you are their Customer. Also they have a lot more muscle with their supplier than you do.

American Muscle will make it right for you. They are very Forum sensitive. IYKWIM.
 
Actually, go right back to American Muscle as you are their Customer. Also they have a lot more muscle with their supplier than you do.

American Muscle will make it right for you. They are very Forum sensitive. IYKWIM.
I did, they said it was over 30 days , so powerstop's warranty would take over from here.... Which was a replacement only. No way in hell I would ever use these on a car again.

I replaced these rotors with factory Ford ones for now, as it is just my daily driver.. I will probably track it a few more times but I am going with girodisc for the track days now...

This has made me re think braking systems all together. Costing me about 7k to re outfit the brakes on my track car... Pretty irritated how they are so nonchalant about it, this could have been a pretty bad day for me or somebody else.
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
441
Southeast
That is a shame as American Muscle advertised it as a Track Day Kit & it has a catastrophic failure on your first track day. I thought AM was better than that.

“I bought a "track day kit" from powerstop off of american muscle with rotors/pads, and on my 4th session of the day I experienced total rotor failure. This was my first track day on these rotors”
 

Bill Pemberton

0ld Ford Automotive Racing Terror
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First, I would recontact American Muscle and comment to them that folks on a a Track Website ( TMO ) mentioned they were a solid company and would help you. Let them know you posted the concern with pictures and their strange response. Good reason for folks on here to contact KNS Brakes or Optimum Performance.

Second , as noted before, a two piece rotor ( suggested Girodisc ) , super quality racing pads , is likely all you really need, the brakes you have are pretty darn good and my personal feeling is a 7K system is not a necessity. Flush the system after each weekend is also my mantra.

Real surprised about American Muscle , but makes one question if that is where they want to buy their modification parts?!
 

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