Cryo Treatment Tech

Vincent Keene · **Posted:** Mon Feb 05, 2007 9:17 am

Graham Jagger wrote:

Vincent Keene wrote:

Current Brakes (from a C4 Corvette)

Front 12.2” x 1.1 thk rotor, dual piston PBR floating caliper, Carbotech XP-8 pads
Rear 12” x .79 thk rotor, single piston PBR floating caliper, NAPA El-cheapo pads

For 2006, I ran Carbotech XP-8s up front, and the PFCM-Z pads in the rear. I ran 7 events with this setup and no ducting. The brakes worked flawlessly…until I cracked a rotor at the PCA event.

You told me that you were going to use the calipers off a ZR1. The ZR1 uses the J55 brakes (HD) from the Z51 option package. Larger caliper than standard and larger rotor. The rotor in the J55 option is 13", not 12". So you have the J55 HD caliper with the JL9 STD rotor. That is a mismatch. They went to the 13" rotor with the J55 caliper to help with heat dissipation. The STD caliper is only a bit smaller, physically, and uses smaller pistons. Mounting brackets are different but both options use the same brake pads.

The front calipers did come off a '95 ZR-1, and the rears came from a 96 GrandSport. Both of these had the J55 brake package.

No room for the 13" rotor behind my backup wheels which are 16". I still have full contact with pad and rotor so I don't see how a mismatch of parts could be the problem. My car should stop fine over and over with these parts.

Vincent Keene · **Posted:** Mon Feb 05, 2007 9:30 am

Graham Jagger wrote:

I think dropping down a grade in pad will be the best option for getting the rotors to last longer. The HP+, or Panther, or maybe try this new sponsors pads and run the Ferodo DS2500. Jim is having good results with his Camaro. They are listed as streetable pads so they could be run all the time.

This is my current plan. The rotors with the heat checks are being resurfaced today. I ordered a set of the Ferodo DS-2500s Friday from Essex. They are cheaper than the XP-8s, but still not cheap.

David Teague · **Posted:** Mon Feb 05, 2007 9:49 am

Bernie Baake wrote:

OK everyone, I conceed your all brake wizzards. Explain for the dummy when GRM tests this theory. It does not hold up. tests show that the Their Kelated Metallic Pads stopped the civic in 87.5% the distance that the organic ones did

Easy, the organic ones they tested were crap. I have always stayed away from organic pads, and at least run semi-mettalic pads. A good semi-mettalic street pad for the local auto parts store will stop the car in the same distance as the race pads. Like my previous example the first few laps out on my street pads on track I can use the same brake points as when I am on race pads however after a few laps they get heat soaked and their performance degrades to the point where I have to get on the brakes earlier and earlier with more pedal pressure and I usually have to back off or pull in for several laps to let them cool down.

In the past I have had discussions with 2 different owners of brake companies and they both agree that race pads will not improve your stopping distance very much, however they will allow you and your brakes to keep functioning at their best.

Vincent, I think you are making the right choice in steeping down in performance on your pads. I also think it would still be worth it to get some temps of your rotors when you get off track to see what your operating range is.

I wish I could find the story on the internet, but one of the tuner mags put a big break kit on and RSX and actually increased the stopping distance by 20 feet over the stock brakes, however they did find they had better life from their rotors and pads and the brakes were easier to modulate.

In the past I have had discussions with 2 differnt owners of brake companies and they both agree that race pads will not improve your stopping distance very much, however they will allow you and your brakes to keep functioning at thier best.

Vincent Keene · **Posted:** Mon Feb 05, 2007 10:47 am

David Teague wrote:

Vincent, I think you are making the right choice in steeping down in performance on your pads. I also think it would still be worth it to get some temps of your rotors when you get off track to see what your operating range is.

I also have some temp indicating paint on the way. I guess VIR-F will be a brake test & tune for me.

Vincent Keene · **Posted:** Mon Feb 05, 2007 2:13 pm

Update.

I picked up the resurfaced rotors at lunch and all the (visible) heat checks are gone.

Hopefully this is good news and a good start for the DS-2500 Ferodo pads.

Graham Jagger · **Joined:** Fri Aug 29, 2003 12:53 am **Posts:** 1718

Vincent Keene wrote:

This is my current plan. The rotors with the heat checks are being resurfaced today. I ordered a set of the Ferodo DS-2500s Friday from Essex. They are cheaper than the XP-8s, but still not cheap.

Good pads are never cheap. I'll be curious as to how you like the DS2500 compared to the XP8. Mark V is testing DS3000/DS2500 combination on his C4. I want to hear how he likes them and how the rotor wear goes.

I figured you probably didn't have enough wheel clearance to use the 13" rotors. They would have given you a bit more material to dissipate more heat.

Do you want those PFC street pads I have? There are a few C4 guys that will take them if you don't.

Vincent Keene · **Posted:** Tue Feb 06, 2007 9:21 am

Graham Jagger wrote:

I'll be curious as to how you like the DS2500 compared to the XP8. Mark V is testing DS3000/DS2500 combination on his C4. I want to hear how he likes them and how the rotor wear goes.

Jim P. is running the DS-2500s on his 1LE too so we all should be able to compare.

Graham Jagger wrote:

Do you want those PFC street pads I have? There are a few C4 guys that will take them if you don't.

Thanks, but no. I have three sets of street pads already. I'm really hoping these new pads can do double duty so I don't have to keep swapping them.

Bernie Baake · **Posted:** Tue Feb 06, 2007 9:46 am

Vincent Keene wrote:

Update.

I picked up the resurfaced rotors at lunch and all the (visible) heat checks are gone.

Hopefully this is good news and a good start for the DS-2500 Ferodo pads.

Vincent hope you get more use out of the resurfaced rotors than I did. I resurfaced my stop tech rotors before Rockingham, ran at the Rock and at CMP and all the surface cracks reappeared. Actually I saw them start right after Rockingham. So after two events they were in the same condition as before I had them resurfaced. I had 5 thousanths removed which removed all signs of cracks.

Vincent Keene · **Posted:** Tue Feb 06, 2007 9:53 am

Bernie Baake wrote:

Vincent hope you get more use out of the resurfaced rotors than I did. I resurfaced my stop tech rotors before Rockingham, ran at the Rock and at CMP and all the surface cracks reappeared. Actually I saw them start right after Rockingham. So after two events they were in the same condition as before I had them resurfaced. I had 5 thousanths removed which removed all signs of cracks.

Only time will tell I guess. Just to be sure I'm covered, I did buy a backup set of rotors that arrived yesterday.

Edit: Bernie, how many events did you have on them before getting them resurfaced?

Bernie Baake · **Posted:** Tue Feb 06, 2007 9:59 am

David Teague wrote:

Bernie Baake wrote:

OK everyone, I conceed your all brake wizzards. Explain for the dummy when GRM tests this theory. It does not hold up. tests show that the Their Kelated Metallic Pads stopped the civic in 87.5% the distance that the organic ones did

Easy, the organic ones they tested were crap. I have always stayed away from organic pads, and at least run semi-mettalic pads. A good semi-mettalic street pad for the local auto parts store will stop the car in the same distance as the race pads. Like my previous example the first few laps out on my street pads on track I can use the same brake points as when I am on race pads however after a few laps they get heat soaked and their performance degrades to the point where I have to get on the brakes earlier and earlier with more pedal pressure and I usually have to back off or pull in for several laps to let them cool down.

So Now your saying there is a difference in stopping distance between OE and high performance pads? Simple Physics David, if you can pull more negative "G's" your stopping faster. If all pads stopped in the same distance then there's no need to use agressive ones. and the heat buildup would also be the same so a milder pad would still cause cracking of the rotor in the same number of braking evolutions.

Bernie Baake · **Posted:** Tue Feb 06, 2007 10:03 am

Vincent I ran three times at Rockingham and once at Roebling, I believe I had two autox events and I drove the vette down to Roebling. following Steve was like a small hpde in itself.

Vincent Keene · **Posted:** Tue Feb 06, 2007 10:09 am

Bernie Baake wrote:

Vincent I ran three times at Rockingham and once at Roebling, I believe I had two autox events and I drove the vette down to Roebling. following Steve was like a small hpde in itself.

Ah, OK. Well I had only Rockingham once on my rotors before the surface cracks appeared. Besides that, Rockingham isn't hard on brakes.

I'm really hoping the pad swap will do the trick, but I'll just have to wait and see.

Bernie Baake · **Posted:** Tue Feb 06, 2007 10:17 am

Vincent, remember you drive much more agressivly than me. Especially the first two events at Rockingham which were my first and second time on track. I truely believe that I was driving at about 75 to 80%. the car was still new. I press a little harded now but nowhere near what you do.

Vincent Keene · **Posted:** Wed Apr 25, 2007 8:46 am

Graham Jagger wrote:

Good pads are never cheap. I'll be curious as to how you like the DS2500 compared to the XP8. Mark V is testing DS3000/DS2500 combination on his C4. I want to hear how he likes them and how the rotor wear goes.

Update on the Ferodo 2500s. I ran them at:

VIR-F - THSCC (street tires)
VIR-F - NASA SE (street tires)
VIR-N THSCC (race tires)

I just pulled the pads last night and they are almost gone. They may last last 1-2 sessions on VIR-S next weekend. 3 events and they are done? :shock:

That's not the result I was looking for.

I was happy with the pad feel and initial bite. They work OK for the street also so I didn't have to swap pads at the track. At $135, that's not an acceptable value IMO so it's time for yet another experiment.

Thoughts?

Aaron Buckley · **Posted:** Wed Apr 25, 2007 9:41 am

Vincent Keene wrote:

Update on the Ferodo 2500s. I ran them at:

VIR-F - THSCC (street tires)
VIR-F - NASA SE (street tires)
VIR-N THSCC (race tires)

I just pulled the pads last night and they are almost gone. They may last last 1-2 sessions on VIR-S next weekend. 3 events and they are done? :shock:

That's not the result I was looking for.

I was happy with the pad feel and initial bite. They work OK for the street also so I didn't have to swap pads at the track. At $135, that's not an acceptable value IMO so it's time for yet another experiment.

Thoughts?

If you're running Corvette brakes, I would be out on the T1 forums and see what they run. - AB

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