Wertles

I have a 2008 427R TrakPak that I bought last year with 6,800 miles on it. Perfect car. It still has the new car smell. Never tracked. I bought it to be my new track car. First time out the harmonic pulley separates. No big deal. 7 year old rubber that sat forever. Put on an ATI damper and all is well. I was finishing up my event yesterday and the brakes were feeling funny. This car came with the 6 piston calipers and 2 piece front rotors. Usually it takes 3-4 laps to get them to get everything up to temp, get the deposits off and smooth out. It never did so I figured they have just warped. Last year I had the rotors turned after the first event because I had a lot of brake pulse that didn't go away. I figured now they are just done so I back off the speeds and just get some easy seat time in. When I get into the pits, both rear rotors are cracked all the way through. The car has a total of 600-800 miles on track so not much at all. The front rotors have multiple hairline cracks but nothing dangerous. I am not running R compound tires so my speeds and braking are reasonable. Brake pads are Hawk DT-70's.

Questions

1. Is this a normal wear interval for rotors under these conditions? Coming from the BMW world, I ran 4 years on my last rotors, well over 3000 track miles and they are still in great shape and on the car. I am hoping someone can tell me that somehow a chunk of steel sitting in a garage for the last 10 years somehow gets brittle and that was my problem. Or at least tell me they have been running these rotors for a long time with no problems at all.

2. Is the friction disk replaceable on these rotors? I thought I remembered seeing them available during my research of this car last year but I can't seem to find that now. They don't appear on the website and was told they only sell the whole two piece rotor. That seems to defeat half the reason for two piece rotors.

3. Are the two piece rotors interchangeable with the stock rotors? Dropping $1000 every 1000 miles will get real old real fast. I'd rather find a more economical solution for the track if that's the case. I can get all 4 rotors of the brand I used to use for $335 but that is only if the front rotors are the same.

4. The front of the car has brake cooling ducts. I need to fabricate a better air inlet in the front bumper. I don't have the plastic pieces which connect the bumper to the hose that were supposed to come with the car and was told by Roush that they don't make them anymore. I just have the hoses sitting behind the screen which is not ideal. Does anyone make a rear cooling kit? Not usually necessary but obviously it's hot enough back there to kill them in a short while.

Otherwise the car is awesome. Except for the 5th gear ratio but that could be a whole different thread.

Thanks for any input.

CoffeeTalkJoe

SWEET Ride!!!

proeagles

Hair line cracks are a big deal. I know a guy with a BMW that had hair line cracks no big deal at Mid-Ohio and he left the track at the end of the straight over 130 mph with no brakes when the rotor exploded. I've tracked and raced BMWs for years and never got the mileage you claim from the BMW. Having said that, that Mustang is heavy and is very hard on brakes. Fix the brake cooling issue and 90 percent of your problem will go away. Can't speak to your other concerns as I'm not familiar with the Roush brake setup on that car. BMW's two piece rotor is not really a two piece in that you can just change the rotor on the hat as you are thinking. The hat is aluminum and the rotor is steel and they are bonded together. The whole assembly is changed as one piece. Probably the same with Roush. If the stock rotors are the same size as they often are, they would be interchangeable.

08'MustangDude

You can get 4-years from rotors at < 5000 miles a year...

I got 221130 miles out of my former '13 Jetta TDI before I had to change the front rotors and
pads, changed the rears four times in that span, rotors on the 3rd. All highway miles though...
Front pads were actually still good, but the rotors were starting feed-back, so they were warping.
I had NO problems stopping either, just good engineering... I sold it back to VW with over 243,000
miles a year ago. The only thing I did were the oil changes, DSG service, and front end links.
Everything else was original, including the the timing and serpentine belts. I also used NON
507.00 spec oil, nothing happened...

I just out slotted and drilled ones on my '15 TSI, no more brake fade, nice stopping power.