Better Brakes
Thread Starter
Burning Brakes
Joined: Oct 2010
Posts: 1,160
Likes: 23
From: Prescott AZ
Better Brakes
I am hoping to get some insights to the best/biggest brakes I can install on my 93 ZR1. It makes me wonder why GM used the brakes that they did for the C4. Weight I guess. The C3 seemed to have better brakes (more pistons, etc.) and they didn't seem to improve them again until the C6. I don't want to change wheels, just want the best brakes that will fit without upsizing the wheels for better breaking on the road race track. What have others done? Any input would be appreciated.
Thanks,
Rob
Thanks,
Rob
Le Mans Master
Joined: Aug 2000
Posts: 8,838
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From: Australia
Le Mans Master
Joined: Mar 2001
Posts: 7,999
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
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Cruise-In IV Veteran
St. Jude Donor '12
If you are going to spend the money on the c5 brake swap you might as well go big brake.
IIRC the willwood kit from summit is less than $2K
And J55 with 3400+lb R comp tires, XP12/10 and bias spring will only last about 15 min before starting to fade on the race track.
IIRC the willwood kit from summit is less than $2K
And J55 with 3400+lb R comp tires, XP12/10 and bias spring will only last about 15 min before starting to fade on the race track.
Race Director
Joined: Jul 2003
Posts: 12,742
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From: Color my life with the chaos of trouble.
What I did... Wilwood kit number 140-8337. You will also need new lines, part 220-8338 if you go with Wilwood.
http://forums.corvetteforum.com/auto...4-it-fits.html
I can drive every bit as deep into corners as the C6Z guys.
http://forums.corvetteforum.com/auto...4-it-fits.html
I can drive every bit as deep into corners as the C6Z guys.
Le Mans Master
Joined: Mar 2001
Posts: 7,999
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
Cruise-In III Veteran
Cruise-In IV Veteran
St. Jude Donor '12
What I did... Wilwood kit number 140-8337. You will also need new lines, part 220-8338 if you go with Wilwood.
http://forums.corvetteforum.com/auto...4-it-fits.html
I can drive every bit as deep into corners as the C6Z guys.
http://forums.corvetteforum.com/auto...4-it-fits.html
I can drive every bit as deep into corners as the C6Z guys.
Melting Slicks
Joined: Jun 2004
Posts: 3,253
Likes: 2
From: Castro Valley CA
I went the C5 route and it is adequate but the pad taper is a real issue. You really need to consider upgrading to 18" wheels ; in addition to vastly superior track tire availability IMO there is a significant brake cooling effect that comes with the increased clearance and the more open wheel design(C5 Z06 style.)
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Team Owner
Joined: Dec 1999
Posts: 34,873
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
What pads do you have now? What pads do you use for tracks days?
The J55 brakes are good and the front rotors are very close to the C5 front rotors in size.
I would suggest for track days:
Install some good air ducting to the front brakes. This is a necessity even with aftermarket brakes.
Replace the stock rubber brake lines with stainless lines (Earls or Goodridge)
Flush the existing fluid and replace with a high performance fluid. I use ATE Super Blue in my 87 and have not boiled the fluid. Other good fluids are Motul 600 and Castrol SRF.
Use good pads. High-performance pads will make a big difference here. (use the search function in the Autocross and Road racing section)
The J55 brakes are good and the front rotors are very close to the C5 front rotors in size.
I would suggest for track days:
Install some good air ducting to the front brakes. This is a necessity even with aftermarket brakes.
Replace the stock rubber brake lines with stainless lines (Earls or Goodridge)
Flush the existing fluid and replace with a high performance fluid. I use ATE Super Blue in my 87 and have not boiled the fluid. Other good fluids are Motul 600 and Castrol SRF.
Use good pads. High-performance pads will make a big difference here. (use the search function in the Autocross and Road racing section)
Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
Dumb question...to the best of my knowledge the J55's where developed from the SCCA Showroom Stock days of the early C4's 84-87, then made available to factory cars. So if they worked in road course racing then, why would they fade now and not work now? Weight difference in the cars is the only thing I can think of that makes sense? Assuming a showroom stock car is still lighter than a actual street showroom stock car.
Melting Slicks
Joined: Jun 2004
Posts: 3,253
Likes: 2
From: Castro Valley CA
Dumb question...to the best of my knowledge the J55's where developed from the SCCA Showroom Stock days of the early C4's 84-87, then made available to factory cars. So if they worked in road course racing then, why would they fade now and not work now? Weight difference in the cars is the only thing I can think of that makes sense? Assuming a showroom stock car is still lighter than a actual street showroom stock car.
Le Mans Master
Joined: Mar 2001
Posts: 7,999
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
Cruise-In III Veteran
Cruise-In IV Veteran
St. Jude Donor '12
Dumb question...to the best of my knowledge the J55's where developed from the SCCA Showroom Stock days of the early C4's 84-87, then made available to factory cars. So if they worked in road course racing then, why would they fade now and not work now? Weight difference in the cars is the only thing I can think of that makes sense? Assuming a showroom stock car is still lighter than a actual street showroom stock car.
You have to find the pads that work for you and can haul it down in a very short distance.
I'm betting it has something to do with in the old days they were running 2+ min laps at Road Atl and to stay mid pack these days you need to do a 1:40. Shoot the other weekend I was hearing 1:27, 1:28, 1:30 laps from the front runners! Thats a LOT of work on the brakes!
I'm sure weights are close.
Safety Car
Joined: Sep 2010
Posts: 3,752
Likes: 190
From: Indiana PA
I have used both the J55 and now the C5's with ducting, SS lines, high temp fluid and proper racing pads. The issue with these brakes is not fade. With a new set of pads, calipers and a good bleed; the J55's are as race worthy today as they were 22 years ago. The problem is the longevity of a good hard pedal due to caliper spread and pad taper. Once the calipers start to spread or pads get a significant taper(longitudinal) the brakes go to S&%t pretty quickly. If you get radial pad taper due to the caliper spreading, you can lose your brakes altogether(happened to me twice at Laguna Seca!) The amount of maintenance and cost of calipers and pads makes the BBK a more reliable and cost effective setup.
