dbs1

I run a 640hp 02 camaro and per the advice of Sam Strano I went to a better set of pads spec'd by him as well as some good fluid. Also using a hydraboost kit. I also have a C5 kit with the bigger rotors.

The car stops as well as my 67 did with Wilwoods all the way around and a hydraboost setup, and I have yet to expereince brake fade during a 20 minute session with speeds around 140mph and with the NT01 tires it flat STOPS!

My problem is that I am now needing a 4th set of rotors in just about 12 sessions or so. My front pads will usually last 6-8 sessions and the rear pads show very little wear while going on the 3rd set of front pads which tells me the back brakes are not being involved much. Sam Strano says that is how the factory set them up and not to monkey with it or I could cause some end swapping, which indeed may be true. On the other hand, I'm getting these solid rotors (just slotted) so hot that they are cracking after just 5-6 sessions and that's using some decent stuff.

Just wondering if anyone else has tried a bias valve on the 4th gen to get some help from the rears and if you have some negative and/or positive feedback from doing so? Thanks!

FASTFATBOY

iTrader: (23)

My buddy had this issue, We have the same setup but I am 500lbs heavier and at the time he had way more power(460 vs my 385). He always complained about the pedal never being the same when he enters the braking zone.

His car was on the rack one day and I happened to look at his rear pads and rotors and made the comment that he had just replaced them....he said no those are the first set. I was shocked.

I told him I go through a set of rears for every 2 or 2.5 sets of fronts. Now its even worse as I pump the brake pedal prior to heavy braking zones because of pad knockback.

At first we thought it was pad knockback, so he bought an Eaton diff and we had the spacer for the axles made thicker by a machine shop to stop the axles from moving around so much. This helped but didn't fix it.

At NOLA it was much worse one day, he noticed his shoe had melted to the floor that day, he brought a temp gun with him and the fronts were really hot and the rears not hot at all. The car had went lean due to a dirty MAF and the headers were cherry red(we figured that out later).

While we had it up insulating the floor I noticed he had taken the heat shield off under the drivers seat that protects the rear brake lines from heat, the bigger exhaust he made put the pipe even closer to those lines going to the rear............It was boiling the brake fluid in the lines going to the rear....he really had no rear brakes at all.

When we fixed that the car began wearing rears like it should.

Since I figured out the pad knockback deal at NOLA last time out I killed a brand new set of Carbotech XP20's on the front in 7.5 sessions, the rears would have made it through the last session but would have been done....they were a set of new XP10's. My car is 3800 lbs and will touch 140 MPH at this track on the front stretch.

When you get the rears working you will have to relearn how to apply the brakes as wheel hop is an issue with these cars, it will make you *** pucker up until you learn where the threshold is.


What pads are you running and what rear end?

Do you have the stock rubber line going to the rear end for the rear brakes?

Why are you changing rotors so often?

Stop buying slotted rotors, buy C6 Vette Brembo blanks.

Rotors will heat "check", thats the nature. I run mine cracked like that....no issues. Unless the crack is big, run it.

Are you running cooling ducts?

Jeff94TA

It's time to add some cooling ducts to the car and the cracking will be greatly reduced. My rear pads and rotors last forever so I agree with Sam on this one. I've only put one set of rotors on the rear since I've owned the car and not too many sets of pads. I run the C5 front brakes as well and never really tried to count the number of rear vs. front because it stops so well. The car sees lots of track time and I'm currently running NASA Time Trials with it.

dbs1

I already have front brake ducts. The previous 2 sets of front rotors cracked from drill hole to drill hole so no more drilled rotors. This current set came from Strano and although not the most expensive, he said they were good ones. After a 20 minute session on the main course at firebird with speeds of 147mph currently the rotors are glowing, but as mentioned the car stops VERY well.

I'd hate to put in an adjustable bias setup and find out Sam was right, that the cat then wants to swap ends.

Right now it's VERY predictable and stops VERY well. Maybe it just is what it is and rotors twice a year is a cheap price to pay for what it does.

I'd have to look up what pads Sam sent me, but as he said, they flat work and they even do well on the street which he was not sure they would. The shop just mentioned the rotors have multiple small heat cracks, though not the terrible feeling in the pedal like the other rotors that cracked all the way through. Hmmm. I've got a call into Strano, I'll see what he suggests. thanks!

ps Of course my mech would like to see me take out more weight and strip the car but I don't see that happening. The car weighs about 3450 with no driver and I'm running the stock rear end with 3.55 gears, TA cover.

FASTFATBOY

iTrader: (23)

When you get on the decent longer straights take your left foot and tap the brake pedal a few times to push the rear pads back up to the rotor before the next brake zone. I do it once or twice.


What kind of ducts, from Blaine Fabrication? Where are you getting air from?

dbs1

I'll try that and see if it makes a diff. My mech grabbed the ducts and flex off the web. Nice setup with ducts located in the front grill.

1981TA

iTrader: (7)

Put in a Ford 9 inch or mod your rear axle to take Ford bolt-in axles (moser makes kits and parts) and you'll eliminate that knock-back issue. But... Dunno if I'd mod a 7.5 inch 10 bolt. I am working with a 8.5 inch 10 bolt as a starting point.

Joseph Freda

You definitely want an adjustable pro portioning valve. You should be trail braking up to the apex. The idea is to keep adding rear brake until the car starts over steering on turn in and then back it off. This will give you even more stopping power plus take some of the load off the front brakes. If the car starts wheel hopping, stiffen the rear shocks if they are adjustable. We are using The wildwood discs and poly matrix pads and they are lasting 4 -6 race weekends no problem. Don't forget to change caliper seals frequently. When they get hot they loose flexibility and the pistons may continue to put pressure on the pads causing drag even when off the brakes.

1981TA

iTrader: (7)

My wilwood adjustable prop valve is mounted on the trans tunnel, just behind the shifter (interior is mostly gutted). Dunno about trail braking coming into a corner. That requires a very fine touch. Over-do it and you won"t have a chance to compensate--your car will just switch ends. Did it once at turn one at Road America. That was what you could call a "pants filling event." Thankfully, I just mowed grass and didn't kiss the wall or another car.

FASTFATBOY

iTrader: (23)

IMO the proportioning valve is a waste of time and money.

Put the correct pad set on the car achieves the same thing. The car has too much rear bias as it is, it doesnt need any more.

I run Carbotech XP20 on the front and XP10 on the rear, I will drop back to XP12 and XP8 this winter.

You cant HOP on the brakes in these cars, you have to sqeeeeeeze them on and when the car is done rotating squeeze a little harder.

You tighten up the rear shocks to fix this(I doubt it will) you will have trouble putting power down out of the corner and possibly make it loose.

brigade24

I run a base C6 setup (kore 3) with blank AC delco rotors and XP12s...I'm on pace to get about 8-9 events out of them. i use scat hosing for ducts...i run the ax pads for autox...testing out carbotech's theory on using the same rotor, so far so good but the ax pads need more initial bite.

as far as rear brakes are concerned, the addition that has had the most impact was a Fays 2 Watts link...when i had a the pan hard system in the rear, under hard braking the axle would "shimmy" or "dance" as it got light making very challenging to brake late/trail brake without the back-end coming loose. That doesn't happen with a Fays 2 since the axle is only allowed to move up and down...plus you can raise or lower your ability to "rear steer". when adjusted properly, it works like a charm...

you probably already knew this but it wasn't mention so...food for thought.

1981TA

iTrader: (7)

Auto-X or Road Race? I can't see getting more than a couple of weekends out of front pads for road racing.

FASTFATBOY

iTrader: (23)

I can't make 8 sessions(2 day weekend) with a set of XP20's.

Haul my 3800 lb barge down from 140 all weekend, last time out I got 7.5 sessions and were to the metal. Ruined my caliper pistons. Now I have to put the Doug Rippie kit in them.....UGHHH.

1981TA

iTrader: (7)

Not fun. I'm doing well enough hauling down 2900 pounds from those speeds, but I did manage to cook both front calipers after my last HPDE. They had 16 sessions, plus about 1000 miles of DD. Once they got overnight cool after the weekend of fun (which I drove home 150 miles from), both seized.

Looking at the bright side though, the pads probably had another 500 miles left in 'em.

I've got Wilwood 6-piston calipers on order now, and cooling ducts already installed.