theamxguy

Just installed Wilwood Spec Corvette front big brake kit with 20 mm thick pads. Properly bedded the pads and then went to Road Atlanta. Did approximately 2 hours of track time. I run in the red group and the car makes 144-146 mph rolling into turn 10. I am running Pirelli scrubs. Best time to date is 1:41.3 measured with RaceChrono Pro on an I phone.. The pads look good, but the rotors are being eaten. They have tiny ridges across the whole face, almost like at high temperatures the BP 40 pad removes the transfer layer of pad on the rotor surface? I can see little to no transfer layer on the rotors. Any of you guys experience that? I have a set of BP 20 pads for the street. If either of these pads kill rotors, I would like to know it now and I will swap pads. A buddy of mine was at the track with me and runs 14 inch Wilwoods and he left his street pads on it. His rotors look almost new and are nice and smooth with a little transfer layer obvious. His car runs 1:55 times and tops at 135 into turn 10. Any pad recommendations from you guys doing street and track. I have heard EBC SR 11 pads don't kill rotors and SR 21 don't either. I haven't been able to find those pads in the Wilwood 6620 brake shape yet. Anyone know a vendor who has them in stock now?

Olitho

A good source of knowledge on available pads is Ken and KNS Brakes.

Also, I always crack my rotors before I wear them out. I hear people talking about pads being hard on rotors. What is hard on rotors is the extreme temperature swings.

I saw your post on the Spec Corvette Facebook page. I think you also said you wore out a set of pads in one day. That is not normal, I don't care what track you are running. Is that correct? If so, perhaps you have some other issue going on?

theamxguy

Thanks for your reply. I am a newbie to the Wilwood Spec Corvette brake scene. Maybe I am anxious for nothing? However, I don't recall posting up on the Spec Corvette Facebook page about this issue? I installed the Wilwoods 5 days ago and I was just at Road Atlanta two days ago, and this is my first post regarding the Wilwoods? I need to start hanging around the Spec Corvette Facebook group because my car is fairly similar. I certainly have burned through stock size C5 brake pads and rotors in one or two track days and these brakes are certainly going to outlast my stock size stuff! I don't have cooling ducts to the spindle yet, so I wonder if that is accelerating the wear. Do most Spec Corvette guys run brake cooling ducts? In our Lemons C4 Corvettes we found that brake ducting extended pad and rotor life on track. (14 inch Wilwood rotors and FNSL calipers and Carbotech RP2 pads).

Olitho

I have personally found brake ducting to not be very effective on the C5. My bottom line decision I made is that it is not worth the expense and maintenance of the ducts. I ran them for a couple of years and then ripped it all out. Essex Brakes has a good white paper on the topic that comes to the same conclusion as I did.

https://www.essexparts.com/news-blog...n-my-track-car

theamxguy

Yes, I read that paper and it is one reason I didn't put ducting on the car. But I still have my Lemons C4 history that clearly demonstrated ducting provided longer brake life with the rigid mounted 14 inch Wilwood rotors and more compact Wilwood calipers in an endurance situation where the cars were run a minimum of 8 hours and up to 24 hours with only fueling and driver change stops.. I have wondered if Essex / AP Racing has superior heat dissipation built into their rotors and calipers? You obviously made a decision based on longevity and hassle, and I will likely stick with my current setup and follow your lead and not duct. I am currently just doing HPDE stuff and not WTW racing with my C5. Thanks again for responding!

rjacobs

I can GUARANTEE you are overheating that pad.

Wilwood says BP40 compound is good to ~1k degrees.

I over heated some G-Loc R8's on my Miata track car and thats a 1250 degree rated pad... smeared the **** out them and eventually the brakes did nothing but chatter across the smeared pad.

Rx7Rob

Last year I got a pre-production set of SR11 and SR21 in 6620 so EBC at least intends to make them.

theamxguy

Rx7Rob, you must have friends in high places! I would love to get some pre-production SR-11 and SR 21 pads to try. How did you like those pads? I am still watching for them in the 6620 size.

Kubs

The pad tearing up rotors is typically a sign that the pad is too cold. I think the BP-40 is too aggressive for your driving, or that track, or both.

Rx7Rob

I thought they felt pretty good. Very close to my typical ST47. Never had any fade with them and my rotor temps were lower than with the 47s. They lay down a thick transfer layer on the rotors. I like them better than BP40's but I'm also probably running much higher temps than you are.

I hated the BP30 and smeared the pad material on the rotor. But I just drove a 2200 lb car in a Champ Car race at Sebring and the BP30 worked great and seemed to last.

RX82Z06

FWIW - installed the Spec Corvette Aero6 front kit with BP30 pads and ran Road Atlanta last weekend for 3 days. Air temps were in the mid 90’s, and the brakes were brilliant. After a light bed-in the BP30’s still needed a couple of sessions to fully bed-in. I run A7’s and no brake duct’s. I previously ran the AP 8350’s and the Wilwood FS6R calipers with every pad option out there, and the Aero6/BP30 combo was a great improvement. Having moved into W2W racing, I needed more thermal mass to manage the high temps. I found this set-up to be fade free with good modulation at some seriously high track temps.

Drive Safe,
Tom

Olitho

APs are fantastic brakes... I forget which kit I have on the GT2 car, but I must say that the Spec Corvette kit on my other car works fantastically well, too. I am generally running Hawk DTC60 pads on the front. I hear Wilwood is now private labeling the Hawkes after previously private labeling Raybestos. The factory change to Mexico for Raybestos reportedly produced pads that are delaminating. I have seen that happen twice recently.