irace1

I would like some suggestions on racing brake pads. During the 25-Hours of Thunderhill, we went through 4 stock C5 front rotors due to cracking on our GTM Supercar. We were also eating pads at an alarming rate. Because this is a project to prove the engineering that went into the street version of this car that is based on a C5 donor, we are reluctant to switch to aftermarket brakes.





We found out after the race, that we may have had the wrong bracket on the front brake calipers, and the pads were mis aligned, allowing the top quarter of an inch of the pads to ride above the rotor. This may have been what was causing our rotors to fail. We have fixed this problem, but I'd like to find out what brake pads racers are using on their stock C5 brakes and any mods that have been done to make the stock brakes perform better.

The GTM only weighs 2400 lbs,and we never got the brakes above 490 degrees during the race weekend, so the stock two-piston brakes should work - with the right pad combination. My previous experience is in a BMW World Challenge car, and we used Hawk HT-10s in the front and Padgid Orange rears on stock E36 brakes, so that is the first change I would go to. I'd like to find out what experienced Corvette racers would suggest.

Thanks

jasonberkeley

Just about all SCCA T1 front-runners are using Hawk DTC-70 pads. The entire brake system, other than the braided stainless lines, is stock.

Some folks are using Carbotechs as well.

Good luck getting the stock brake-system to last without replacing rotors or pads for a race of that length. It's not going to happen! You will also notice that the calipers flex and "spread," causing accelerated pad wear.

irace1

Thanks for the advice. We've run cars with stock Ford Fox Body, Ford SN95 and BMW E36 brakes in the 25-hour over the last 5 years and only changed one rotor and maybe one caliper over that period. It's a matter of getting the combination right.

AU N EGL

If your running the Endros, time for a BBK. Bigger rotors and thicker pads.

irace1

Trust me, we'd love to go to bigger brakes, but right now, as a factory backed team, our mission is to prove that the stock C5 components used to build the street version of the GTM is up to the task of winning our class at the 25-Hours of Thunderhill and NASA's Western Endurance Championship.

bowmanized

What kind of pads did you use during the 25hr?
Are you using brake ducts?

AU N EGL

Time to tell GTM the stock brakes are not up the task.

Miaugi

Brake pads are like sports...eveybody has their favorites.

I have been using Carbotechs as do many others here and although some say they do not last long enough, they are certainly easy on rotors.

bowmanized

Yeah some are easier on rotors than others though. Organic pads specifically. I know Pagid Orange or Blue would be a better option than Hawk DTC-70 from a rotor life perspective.

0Anthony @ LGMotorsports

As far as pads go we spent the last year with Cobalt Racing and their XR2 compound pad on our World Challenge cars. I carry these for the StopTech kits as well as your factory calipers. They have another very popular option which is the GTS pad for less aggressive HPDE events as well.

If you are seeing rotor cracking it can be from a number of different issues, either not enough cooling, cooling in the wrong location, pad material, under sized brakes, or just a bad quality rotor in general.

Doing endurance racing on stock brakes is going to be impossible without running into brake problems.

Do you have pictures of the cracking?

John Shiels

25 hour brake systems are not OEM GM brakes you are trying the impossible even though you car is light.

How could the pads be past the rotor edge when you put them together, was it not visable?

What factory is backing you I guess GMT?

Brake cooling is?

Where did you measure the temp?

What was the weight of the previous cars yu raced?

Wilwood H seemed to crack my rotors but wear them slighty compared to others. Your rotors should get up to temp then stay there so cracking may be less.

Stoptech direct replacement rotors from LGM would last longer I have found and they swap right in.

wtknght1

I love the Carbotechs and have found they last at least as long as everybody else's stuff and in extreme cases, they seem to last longer (for me anyway). The Sebring 07 race is a perfect example - while everybody else ran out of brakes, the Carbos were still stopping me and I had pad left at the end.

For endurance racing, it's all about pace calculation. Yeah, you can run ***** to the wall if you want, but that's going to mean you replace pads, rotors, etc during the race which takes time. If you go slower and conserve parts, you don't have to change parts as often...but you go slower.

I've run some 3-hour enduros with a stock weight Vette (about 3300lbs) and made the brakes last, but for 24 hours, you'll have to change the pads several times...no matter what you run...if you want to win. The rotors should do better because you're not really allowing them to cool, but you're still going to crack a few. Again though, the key is finding the right pace and driving conservatively til you get toward the end of it. Then figure out how much tire, brake, etc is left and bring it home. Good luck.

DOUG @ ECS

but there should be some leway given due to the weight of that car.

0RAAMaudio

I came close to building a GTM for track use only but decided I just do not have the time to build and run a limited production car, really wish I could though!


I understand wanting to run with stock brakes but it seems you are going to continue having problems with them. I would contact all the T1 guys you can find or search wherever they hang out and see what is the best setup they use, possibly you can find something that will be tolerable at least.

If you want to try a set of Performance Friction Carbon Metalic rears I have a NIB set I am not going to be using, I will sell them for a very reasonable price to help you out a bit.

I just upgraded to 6/4 piston Stoptechs as I know two ST1 drivers that had incredible reliability with them, no 24 racers but allot of races, many in really hot weather, in the end better brakes, more reliable, far longer service life, less costly.


The PF part number is 0732.101.17.44

Good luck!

Rick