How good are C4 Brake calipers?
03-01-2010, 11:47 AM
#21
Le Mans Master
Seriously, what all did you just say?
03-01-2010, 12:02 PM
#22
Race Director
06-01-2015, 06:06 PM
#24
What year C4 do you own (nothing listed in your profile)? "Late-model" C4's 95 and late had the J55 brakes as standard and were optional since 1989. All ZR-1's had the J55 brakes.
The J55 caliper is larger (wider) to accommodate the slightly wider 13" J55 rotor. There are a wide variety of performance pads available for the C4 brakes ranging from good HPDE pads to race-level stuff. Same with rotors; some people use a generic stock rotor and toss them when they wear out, some go for high-zoot rotors made for extreme braking.
I did a C5 brake upgrade on my 87 last summer and there was a marked improvement but the 87 front rotors were only 11.8" wide and relatively thin. With the C5 stuff in front, I now have a much wider range of brake components to use. I also added a Doug Rippie brake bias spring to help with the extra braking power up front. It's almost a necessity to keep from the ABS going nuts at even medium braking effort.
But adding C5 front brakes may require a different wheel. The OEM "salad-shooter" wheels do not work with C5 front brakes; the caliper is too large so something like a ZR-1 style wheel is needed.
The rear C4 brakes are very close in size to C5 rear brakes, so pad choice is the big factor out back. Add some good quality brake fluid with at least a DOT4 boiling point. cooling ducts to the front brakes, and stainless flex lines and you should be able to handle many tracks.
The J55 caliper is larger (wider) to accommodate the slightly wider 13" J55 rotor. There are a wide variety of performance pads available for the C4 brakes ranging from good HPDE pads to race-level stuff. Same with rotors; some people use a generic stock rotor and toss them when they wear out, some go for high-zoot rotors made for extreme braking.
I did a C5 brake upgrade on my 87 last summer and there was a marked improvement but the 87 front rotors were only 11.8" wide and relatively thin. With the C5 stuff in front, I now have a much wider range of brake components to use. I also added a Doug Rippie brake bias spring to help with the extra braking power up front. It's almost a necessity to keep from the ABS going nuts at even medium braking effort.
But adding C5 front brakes may require a different wheel. The OEM "salad-shooter" wheels do not work with C5 front brakes; the caliper is too large so something like a ZR-1 style wheel is needed.
The rear C4 brakes are very close in size to C5 rear brakes, so pad choice is the big factor out back. Add some good quality brake fluid with at least a DOT4 boiling point. cooling ducts to the front brakes, and stainless flex lines and you should be able to handle many tracks.
Also seems that dot 4 is an heavier fluid than dot 3
06-02-2015, 11:00 AM
#25
Team Owner
For street use (including some "spirited driving" on the Autostrade
), a DOT3 fluid works fine. Fluids from Valvoline or Castrol will work very well.I use a DOT4 fluid (ATE Super Blue) in my '87 autocross and track car. Never had an issue with seals in the master cylinder or the calipers. I buy the ATE fluid in one-liter cans as I do a fluid flush before every track day. Motul is another good DOT4 fluid for high performance use.
Note that the US government has recently decided that any brake fluid that is not a clear or yellow to golden color cannot be used or sold for use in the US. So we can't get ATE Super Blue fluid anymore but the ATE TYP200 fluid is available. The only difference in the two is the color...
You could use a DOT4 fluid in the clutch hydraulics, but any good grade of a DOT3 fluid will work fine. Just get a small can and mark it for "Clutch only".
06-02-2015, 11:27 AM
#26
Instructor
I think people get caught up too much on comparing these calipers to brand new stuff....
I road course race a 1973 Porsche 914 with stock rebuilt Girling Brake Calipers on vented/drilled rotors....no issues whatsoever and those brakes are tiny..
That being said, i've also tracked a 1996 LT4 and experienced very bad brake fade and brake loss. Solved that with Stainless Steel Lines, Dot 4 Fluid, better pads, a good bleed, good working master/slave cylinder, good vented rotors and you should be fine.
You can buy rebuild kits for the J55 Calipers as well...I just rebuilt them over in my restoration thread if you want to check it out. The brakes start here https://www.corvetteforum.com/forums...rogress-3.html then go on for a few pages i believe.
I road course race a 1973 Porsche 914 with stock rebuilt Girling Brake Calipers on vented/drilled rotors....no issues whatsoever and those brakes are tiny..
That being said, i've also tracked a 1996 LT4 and experienced very bad brake fade and brake loss. Solved that with Stainless Steel Lines, Dot 4 Fluid, better pads, a good bleed, good working master/slave cylinder, good vented rotors and you should be fine.
You can buy rebuild kits for the J55 Calipers as well...I just rebuilt them over in my restoration thread if you want to check it out. The brakes start here https://www.corvetteforum.com/forums...rogress-3.html then go on for a few pages i believe.
06-02-2015, 04:51 PM
#27
I think people get caught up too much on comparing these calipers to brand new stuff....
I road course race a 1973 Porsche 914 with stock rebuilt Girling Brake Calipers on vented/drilled rotors....no issues whatsoever and those brakes are tiny..
That being said, i've also tracked a 1996 LT4 and experienced very bad brake fade and brake loss. Solved that with Stainless Steel Lines, Dot 4 Fluid, better pads, a good bleed, good working master/slave cylinder, good vented rotors and you should be fine.
You can buy rebuild kits for the J55 Calipers as well...I just rebuilt them over in my restoration thread if you want to check it out. The brakes start here https://www.corvetteforum.com/forums...rogress-3.html then go on for a few pages i believe.
I road course race a 1973 Porsche 914 with stock rebuilt Girling Brake Calipers on vented/drilled rotors....no issues whatsoever and those brakes are tiny..
That being said, i've also tracked a 1996 LT4 and experienced very bad brake fade and brake loss. Solved that with Stainless Steel Lines, Dot 4 Fluid, better pads, a good bleed, good working master/slave cylinder, good vented rotors and you should be fine.
You can buy rebuild kits for the J55 Calipers as well...I just rebuilt them over in my restoration thread if you want to check it out. The brakes start here https://www.corvetteforum.com/forums...rogress-3.html then go on for a few pages i believe.
Power stop brake kit could work better?
06-02-2015, 07:22 PM
#28
Team Owner
I've recently replace all old fluid with motul dot 3/4 and rear brake pads and i've got a little improvment in brake power, still I had to replace front brake pads, however seems that c4 1995 is a little it insufficient in brake power.. Don't you?
Power stop brake kit could work better?
Power stop brake kit could work better?
Also, how old are the flexible brake lines at each caliper? Going with a braided steel line like those from Earl's or Goodridge can help with better pedal feel. If the lines are original to the car, it's probably time to replace them.
If the rotors are original, it can't hurt to replace those too. For street use, there is nothing wrong with an OEM style rotor. Rotors that are drilled, slotted, or both may look good, but for general street use, they don't provide a lot of braking improvement.
06-03-2015, 03:32 AM
#29
What should work is the proper selection of brake pads. There are a number of good semi-metallic pads available that will provide an increase in braking performance. You may want to exchange PM's with Adam at CarboTech (a supporting vendor) he can give you some good information on suitable pads. You will need to find out if his company will do international shipping.
Also, how old are the flexible brake lines at each caliper? Going with a braided steel line like those from Earl's or Goodridge can help with better pedal feel. If the lines are original to the car, it's probably time to replace them.
If the rotors are original, it can't hurt to replace those too. For street use, there is nothing wrong with an OEM style rotor. Rotors that are drilled, slotted, or both may look good, but for general street use, they don't provide a lot of braking improvement.
Also, how old are the flexible brake lines at each caliper? Going with a braided steel line like those from Earl's or Goodridge can help with better pedal feel. If the lines are original to the car, it's probably time to replace them.
If the rotors are original, it can't hurt to replace those too. For street use, there is nothing wrong with an OEM style rotor. Rotors that are drilled, slotted, or both may look good, but for general street use, they don't provide a lot of braking improvement.
Thank you great info...
I will take a look at these stores
06-03-2015, 10:57 AM
#30
Supporting Vendor
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St. Jude Donor '11,'13
We can ship anywhere shoot me a PM or email what you need or tell me what you are looking to accomplish and I will be happy to help.
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Adam Adelstein
Amp’D Autosport.com
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Adam Adelstein
Amp’D Autosport.com
Internet's largest retailer of Carbotech Performance Brake Pads.
PH:216-780-8825.
Email: sales@ampdautosport.com
Web Site & Direct ordering http://ampdautosport.com/
All major CC and Pay Pal accepted.
Check out Promo code:z28
06-04-2015, 09:06 PM
#32
Drifting
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Did an emergency stop in the german autobahn at top speed to full stop.
The J55 roared loud and the corvette stopped without hesitation.
Indeed, the corvette slowed down faster and shorter than the 911 next to me. :-)
The J55 roared loud and the corvette stopped without hesitation.
Indeed, the corvette slowed down faster and shorter than the 911 next to me. :-)
06-04-2015, 11:04 PM
#33
Racer
I just got done switching out the brakes on my 92 C4 using a conversion kit including C5 calipers and rotors ... WOW, quite a difference!!! The C5 calipers have twin pistons while the C4's use only a single piston. But the overall improvement (noticeable), I think lies mostly in the larger and better-designed rotors. If you have a C4, want to improve the braking and are willing to spend the money, the swap kit available from VB & P Brakes ( http://www.vbandp.com ) includes quality components nicely finished in your choice of powder coatings. The only potential drawback is that the kit requires the use of A-mold style wheels to ensure proper fitment. However, not to worry ... look at some pics ... A-molds look SWEET on C4s.
