C5 HPDE car: Front c5 caliper in rear, c6 caliper in front? Good or bad idea?
09-12-2016, 04:04 PM
#1
Drifting
Thread Starter
C5 HPDE car: Front c5 caliper in rear, c6 caliper in front? Good or bad idea?
would this be so wildly off balance that its not worth doing? require a bias and then be a great idea? require a bias adjuster and still suck?
thoughts please
thoughts please
09-14-2016, 02:17 AM
#2
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,078
Received 8,918 Likes
on
5,327 Posts
C5 and Base C6 calipers are the same front and rear. The C6 Z51 cars had 3 mm smaller pistons in the rear calipers due to the larger rotors being run on the C6 Z51. Thus it depends on which car the C6 caliper is taken from. If you add the C6 Z51 front and rear calipers, brackets and rotors you will the C5 brake bias.
Bill
Bill
Last edited by Bill Dearborn; 09-14-2016 at 02:22 AM.
09-14-2016, 09:34 AM
#3
Le Mans Master
C5 and Base C6 calipers are the same front and rear. The C6 Z51 cars had 3 mm smaller pistons in the rear calipers due to the larger rotors being run on the C6 Z51. Thus it depends on which car the C6 caliper is taken from. If you add the C6 Z51 front and rear calipers, brackets and rotors you will the C5 brake bias.
Bill
Bill
In general, it's a bad idea. You will most likely have bias issues but I'm not sure if you could get around that by using different pad compounds on each end and relying on the Active Brake Proportioning.
09-14-2016, 10:20 AM
#4
Drifting
Thread Starter
I think he's asking about putting the front C5 calipers on the rear and then putting front C6 calipers on the front. But as Bill said, the front calipers are essentially the same.
In general, it's a bad idea. You will most likely have bias issues but I'm not sure if you could get around that by using different pad compounds on each end and relying on the Active Brake Proportioning.
In general, it's a bad idea. You will most likely have bias issues but I'm not sure if you could get around that by using different pad compounds on each end and relying on the Active Brake Proportioning.
09-14-2016, 10:22 AM
#5
Safety Car
I'm not sure what the OP is trying to do.
I get the feeling he wants to play with brake bias. My suggestion is to talk to the brake pad people and use different pads on the front and rear of the car. You can do some really neat things this way - if you have proper guidance.
This is an HPDE car and not a race car so we don't know the reasoning for all of this.
Richard Newton
Brake Temperatures on the Track
I get the feeling he wants to play with brake bias. My suggestion is to talk to the brake pad people and use different pads on the front and rear of the car. You can do some really neat things this way - if you have proper guidance.
This is an HPDE car and not a race car so we don't know the reasoning for all of this.
Richard Newton
Brake Temperatures on the Track
09-14-2016, 10:26 AM
#6
Drifting
Thread Starter
I'm not sure what the OP is trying to do.
I get the feeling he wants to play with brake bias. My suggestion is to talk to the brake pad people and use different pads on the front and rear of the car. You can do some really neat things this way - if you have proper guidance.
This is an HPDE car and not a race car so we don't know the reasoning for all of this.
Richard Newton
Brake Temperatures on the Track
I get the feeling he wants to play with brake bias. My suggestion is to talk to the brake pad people and use different pads on the front and rear of the car. You can do some really neat things this way - if you have proper guidance.
This is an HPDE car and not a race car so we don't know the reasoning for all of this.
Richard Newton
Brake Temperatures on the Track
09-14-2016, 09:24 PM
#7
Instructor
I run stoptech in front and base c5 fronts in the rear. You will lose your ebrake if you care, also remember that front pads cost more than rear pads. So be sure you are okay with those two things.
09-14-2016, 09:29 PM
#8
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,078
Received 8,918 Likes
on
5,327 Posts
Bill
09-14-2016, 11:07 PM
#9
Drifting
Thread Starter
really?? that bad?? i had noticed that for like $800 more (and whats $800 in the grand scheme of things when there's thousands in road race parts added..) i could get into the entry level BBK's. but i didnt know c6z brakes had issues? elaborate? and yes i even searched for c6z brake swaps before posting, and i know a few people said they werent fans, but they didnt specify they had caliper issues.
09-15-2016, 08:44 AM
#10
Instructor
I went through the same thing when I went into searching for a BBK.
i found that not a lot of people cared for the c6z brakes. The pads slip and the adjustment bolts break, round out, and the design in general is poor.
I was also told that the stock brakes would work just as well with proper pads.
Jump ahead a ad a month after researching non stop I finally settled on a StopTech kit. It was a little more but in the end I am glad I just didn't cheap out. I paired them with some Cobalt pads XR1for track and XR3 for road and AutoX.
as mentioned before, I moved the front calipers to the rear. Removed the Ebrake and I don't feel any bias issues. This is common when upgrading to a larger performance brake. however I am. It sure I would move them to the back with a c6z front and a c5 base front in the rear.
its your money in the end, so do what you want. But I can tell you, you're going to be much happier in the end not wasting money "to have it now". Save up for a couple more months if you have to and get a real BBK. Because buying a c6z kit your always going to be thinking or wishing you had gotten a real kit.
i found that not a lot of people cared for the c6z brakes. The pads slip and the adjustment bolts break, round out, and the design in general is poor.
I was also told that the stock brakes would work just as well with proper pads.
Jump ahead a ad a month after researching non stop I finally settled on a StopTech kit. It was a little more but in the end I am glad I just didn't cheap out. I paired them with some Cobalt pads XR1for track and XR3 for road and AutoX.
as mentioned before, I moved the front calipers to the rear. Removed the Ebrake and I don't feel any bias issues. This is common when upgrading to a larger performance brake. however I am. It sure I would move them to the back with a c6z front and a c5 base front in the rear.
its your money in the end, so do what you want. But I can tell you, you're going to be much happier in the end not wasting money "to have it now". Save up for a couple more months if you have to and get a real BBK. Because buying a c6z kit your always going to be thinking or wishing you had gotten a real kit.
09-15-2016, 09:59 AM
#11
Drifting
Thread Starter
I went through the same thing when I went into searching for a BBK.
i found that not a lot of people cared for the c6z brakes. The pads slip and the adjustment bolts break, round out, and the design in general is poor.
I was also told that the stock brakes would work just as well with proper pads.
Jump ahead a ad a month after researching non stop I finally settled on a StopTech kit. It was a little more but in the end I am glad I just didn't cheap out. I paired them with some Cobalt pads XR1for track and XR3 for road and AutoX.
as mentioned before, I moved the front calipers to the rear. Removed the Ebrake and I don't feel any bias issues. This is common when upgrading to a larger performance brake. however I am. It sure I would move them to the back with a c6z front and a c5 base front in the rear.
its your money in the end, so do what you want. But I can tell you, you're going to be much happier in the end not wasting money "to have it now". Save up for a couple more months if you have to and get a real BBK. Because buying a c6z kit your always going to be thinking or wishing you had gotten a real kit.
i found that not a lot of people cared for the c6z brakes. The pads slip and the adjustment bolts break, round out, and the design in general is poor.
I was also told that the stock brakes would work just as well with proper pads.
Jump ahead a ad a month after researching non stop I finally settled on a StopTech kit. It was a little more but in the end I am glad I just didn't cheap out. I paired them with some Cobalt pads XR1for track and XR3 for road and AutoX.
as mentioned before, I moved the front calipers to the rear. Removed the Ebrake and I don't feel any bias issues. This is common when upgrading to a larger performance brake. however I am. It sure I would move them to the back with a c6z front and a c5 base front in the rear.
its your money in the end, so do what you want. But I can tell you, you're going to be much happier in the end not wasting money "to have it now". Save up for a couple more months if you have to and get a real BBK. Because buying a c6z kit your always going to be thinking or wishing you had gotten a real kit.
09-15-2016, 10:41 AM
#12
Former Vendor
The old "put the fronts on the rear" format has been around for years. And for the most part it's proven in the end to be a band-aide idea at best. The notion that just because you can doesn't mean you should.
Front calipers are front calipers for a reason; they have more piston area. This is what keep brake balance or 'bias' in check. The rears of course are smaller. Moving larger bores to the rear would be ok...if you at the same time increased the front area keeping the balance within say 5% or so. But moving dedicated fronts to the rear can result in a near 50/50 brake bias. That might be ok on a Porsche but not so much on a Vette.
The side effect of such changes is a longer, softer pedal. All that area requires more volume displacement resulting in a less than favorable pedal experience. Tactical feel is lost on the softer response.
Clearly all these changes are in the eye of the buyer...and there are one or two who will swear by such changes being perfect. Good for them, but I suspect few of them are at the front of the groups in HPDE weekends like Bill an others who have not only learned the hard way but are very open about sharing their knowledge.
Spend a bit more one time and do it right. There are a few affordable options that could be classified middle of the road as in Caliper Kits for the stock rotor. One step below the full blown BBK they use oe spec rotors but offer the option of many pad choices and proper brake balance in their design.
Front calipers are front calipers for a reason; they have more piston area. This is what keep brake balance or 'bias' in check. The rears of course are smaller. Moving larger bores to the rear would be ok...if you at the same time increased the front area keeping the balance within say 5% or so. But moving dedicated fronts to the rear can result in a near 50/50 brake bias. That might be ok on a Porsche but not so much on a Vette.
The side effect of such changes is a longer, softer pedal. All that area requires more volume displacement resulting in a less than favorable pedal experience. Tactical feel is lost on the softer response.
Clearly all these changes are in the eye of the buyer...and there are one or two who will swear by such changes being perfect. Good for them, but I suspect few of them are at the front of the groups in HPDE weekends like Bill an others who have not only learned the hard way but are very open about sharing their knowledge.
Spend a bit more one time and do it right. There are a few affordable options that could be classified middle of the road as in Caliper Kits for the stock rotor. One step below the full blown BBK they use oe spec rotors but offer the option of many pad choices and proper brake balance in their design.
09-15-2016, 10:48 AM
#13
Drifting
Thread Starter
The old "put the fronts on the rear" format has been around for years. And for the most part it's proven in the end to be a band-aide idea at best. The notion that just because you can doesn't mean you should.
Front calipers are front calipers for a reason; they have more piston area. This is what keep brake balance or 'bias' in check. The rears of course are smaller. Moving larger bores to the rear would be ok...if you at the same time increased the front area keeping the balance within say 5% or so. But moving dedicated fronts to the rear can result in a near 50/50 brake bias. That might be ok on a Porsche but not so much on a Vette.
The side effect of such changes is a longer, softer pedal. All that area requires more volume displacement resulting in a less than favorable pedal experience. Tactical feel is lost on the softer response.
Clearly all these changes are in the eye of the buyer...and there are one or two who will swear by such changes being perfect. Good for them, but I suspect few of them are at the front of the groups in HPDE weekends like Bill an others who have not only learned the hard way but are very open about sharing their knowledge.
Spend a bit more one time and do it right. There are a few affordable options that could be classified middle of the road as in Caliper Kits for the stock rotor. One step below the full blown BBK they use oe spec rotors but offer the option of many pad choices and proper brake balance in their design.
Front calipers are front calipers for a reason; they have more piston area. This is what keep brake balance or 'bias' in check. The rears of course are smaller. Moving larger bores to the rear would be ok...if you at the same time increased the front area keeping the balance within say 5% or so. But moving dedicated fronts to the rear can result in a near 50/50 brake bias. That might be ok on a Porsche but not so much on a Vette.
The side effect of such changes is a longer, softer pedal. All that area requires more volume displacement resulting in a less than favorable pedal experience. Tactical feel is lost on the softer response.
Clearly all these changes are in the eye of the buyer...and there are one or two who will swear by such changes being perfect. Good for them, but I suspect few of them are at the front of the groups in HPDE weekends like Bill an others who have not only learned the hard way but are very open about sharing their knowledge.
Spend a bit more one time and do it right. There are a few affordable options that could be classified middle of the road as in Caliper Kits for the stock rotor. One step below the full blown BBK they use oe spec rotors but offer the option of many pad choices and proper brake balance in their design.
but, in light all of the above info, ill just make the leap to BBK. ive been on that line, anyway.
09-15-2016, 01:59 PM
#14
Former Vendor
But both have the the same or near identical piston area from the factory.
My guess is that you're saying..."no, one is a big six pot, the other a two piston slider Todd"...and you'd be correct. However piston area as defined by it's clamping force is the same.
The six pot has (example) three pistons (small) behind the pad(s) that have about 4sq" of area. The two piston slider has two pistons (medium size) that have about 4sq" of area.
One is fixed creating equal are of piston pressure on both sides. The other works on a push/pull manner and thus also provide the same pressure to the outside as they do the inside.
*Both could be defined also as having 8" of area..one with pistons, the other with its mechanical design.
The following users liked this post:
sean.b (09-15-2016)
09-15-2016, 04:16 PM
#17
Former Vendor
Not beating up on you...just educating for the benefit of all. Sometimes things are not what they first seem.
09-18-2016, 05:51 PM
#18
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,078
Received 8,918 Likes
on
5,327 Posts
really?? that bad?? i had noticed that for like $800 more (and whats $800 in the grand scheme of things when there's thousands in road race parts added..) i could get into the entry level BBK's. but i didnt know c6z brakes had issues? elaborate? and yes i even searched for c6z brake swaps before posting, and i know a few people said they werent fans, but they didnt specify they had caliper issues.
Second problem is the so called padlet design. The padlets all taper at different places. If you are adept you can pull the caliper and swap them around in the caliper to offset the tapering but that gets to be a PIA. There are single piece pads that are available but they are comparatively expensive and are still thin.
Third problem is the tendency for the pad guide pins to freeze in the caliper and be so frozen that tools will break off when you try to get them loose. After your first track day they will be frozen into the caliper. However, every once in a while they will surprise you when they get hot on the track and will come loose. If they come loose on the outside of the caliper they will extend into the back side of the wheel spoke and if you are lucky the only thing that will happen is a deep scratching of the spokes. Some people have had the spokes break which can be fun at 150 mph. I had frozen pins with a high strength Torx bit broken off in one of them and one day one pin backed out and scratched the back of my wheel which turned out to be repairable. Others had a pin on the inside of the caliper come loose with the subsequent loss of a padlet (not likely with a single piece pad) and another exciting period when the brakes were applied.
Fourth problem is they tend to boil the brake fluid more than other calipers. In 17 years of doing HPDEs I always used excellent brake fluid and had good cooling going to my brakes. The one problem I never had until I ran the C6Z with stock brakes was fluid boiling. They would get hot on track and would start to pull to one side or the other under braking. If I slowed down below a certain speed the cooling air would stop and the brake fluid would boil. This happened after I came off track one time and while driving through the paddock somebody walked in front of me and I almost ran over them because there were no brakes.
When I first purchased my 08Z in August of 09 everybody that I participated in track events with told me to ditch the stock calipers. I tried to make them work for a year and a half and finally went with Wilwoods. With the same brake ducts in place as soon as I went to the Wilwood calipers I stopped having brake fluid boiling issues.
Other than those few important issues they may be good calipers.
Bill
Last edited by Bill Dearborn; 09-18-2016 at 05:51 PM.
09-19-2016, 12:07 PM
#19
Racer
Sean listen to the experts. You can get more brake bite with pads, and maintain fr / rr balance which is critical on track. Also read Johnny's 'Brake Questions' thread in this section.
09-19-2016, 12:09 PM
#20
Drifting
Thread Starter
