1 track day killed my rotors

[-SS454-]

I tracked my car once before with the Wilwood BP-10 pad, and brake wear was really good and virtually no wear on the rotor. A few days ago I switched to the BP-20 pad, bedded them in, then yesterday did another track day. The results was these completely ate my rotors up. I've seen plenty of other people using an actual race pad and not have wear like this. Could it be brakes were getting too hot? Maybe too cold? Wilwood says rotor grooving is normal, but I think this is very excessive for the BP-20 pad. Note, after the cool down lap and in the pits, surface temps were showing around 380F, suggesting the pads must have been getting to around 1000F.

https://static1.pt-content.com/images/noimg.gif

Car is a 1971 Chevelle. 3703 lbs without driver
Wilwood 11.75x1.25 GT48 front discs
Superlite 4 calipers
Rear drums with "performance" NAPA shoes
Top speed at track is about 96 mph for me.

Thanks

[Pete68]

You have 11 inch rotors and a 4000 lb car with you in it. Thats a lot of work for those small rotors. They just cant dissipate all that heat esp coming down from 97 mph. I would upgrade to 13 or 14 inch rotors if you are going to track the car a lot. I dont think any pad is going to solve the problem, its basic physics.

Yes going with bigger brakes forces a change to bigger wheels but that gives you a two fold benefit, with bigger wheels, 17 or 18 inch you can get much much better tires that a stickier and better for the track.

Or maybe stick to autocross where the speeds are lower.

[mitch_04]

Can you route some brake cooling ducts to the front brake pads?

Do you have an adjustable proportioning valve?

Maybe you would be able to give your rear brakes a little more of the work to take a little load off the front.

[Rod]

rotors are a wear item, when using racing pads.....did it stop better?

[-SS454-]

You have 11 inch rotors and a 4000 lb car with you in it. Thats a lot of work for those small rotors. They just cant dissipate all that heat esp coming down from 97 mph. I would upgrade to 13 or 14 inch rotors if you are going to track the car a lot. I dont think any pad is going to solve the problem, its basic physics.

Yes going with bigger brakes forces a change to bigger wheels but that gives you a two fold benefit, with bigger wheels, 17 or 18 inch you can get much much better tires that a stickier and better for the track.

Or maybe stick to autocross where the speeds are lower.

Nearly 12" and 3900 lbs with driver :P But yes its a lot of weight for a small rotor. Currently no plans to change to large brakes and big wheels. Fully aware the performance gains of it, but that isn't the purpose of the car. Goals are to drop 400 lbs off the car over time, which will help. I may redesign the caliper brackets and upgrade to a 12.19" rotor at a later time though. Unfortunately it's a custom CNC job.

I pulled the wheel today and found the brake pads are done too. Oddly the inner pad wore away much quicker, which is strange to me.

[-SS454-]

Can you route some brake cooling ducts to the front brake pads?

Do you have an adjustable proportioning valve?

Maybe you would be able to give your rear brakes a little more of the work to take a little load off the front.

I have bought cooling ducts, just trying to figure a way to mount them. Need to design a spindle duct too.

I do have a proportioning valve. I did crank some more rear brake in it, but it may not have been enough. I really don't want to crank too much brake in and find the rears locking up. Also I run rear drums, and they really can't handle the heat at all.

[-SS454-]

rotors are a wear item, when using racing pads.....did it stop better?

The BP-20s aren't a racing pad, I think that's my whole concern. It's one step up over the BP10s which is Wilwood's most street oriented pad. They did stop better though. Never would expect such destruction on the pads and rotors given the BP-10s lived perfectly well during a track day.

[Rick Dorion]

Did you upgrade the pads to resolve an issue? Maybe the BP10's will suffice for your intended use.

[-SS454-]

I went with different pads because I wanted more brake. I also felt the BP-10s fell outside their optimal temps and after a couple laps they wouldn't have as much bite, but would never fade.

[rixtrix1]

You said the inside pads wore more, are you sure the caliper isn't sticking due to heat?