RedLS1GTO

I have posted a couple of threads on here lately asking questions about brakes for my C4 track car. I'm combining them into one consolidated thread with this one.

I don't have a whole lot of time in the car, but I think I am learning how to handle it pretty well. I'm doing HPDEs right now and would eventually like to get into actual competition with it. It has stock Grand Sport calipers with Hawk pads on it currently. With a lot of power and a lot of straightaway speed, not having confidence in the brakes is not a good thing and as of now I don't. What do you C4 guys recommend? I am trying to keep the budget as small as possible but after the recent Mid-Ohio post, I want to make sure that I have done everything I can with the brakes.

Basically I am looking for suggestions as to what to do along those lines. Am I good with stock calipers and good pads and rotors? Is it worth it to invest in some aftermarket systems like the Wilwood, Brembo, Baer, etc? If so which one? I am running on 17" CCW classics and at least for now don't want to have to change wheels.

Thanks in advance!!

rfn026

I wouldn't spend a lot of money here. I think the setup you have is just fine or what you're doing. Instead of spending money on parts hire a driving coach. You'll get a far greater return on investment.

I use a stock C4 setup except for 2-piece Wilwood rotors and a different bias spring. I also use Wilwood A pads. D.J Race Enterprise has consistently used stock Corvette calipers and they always outbreak the aftermarket systems. You might want to talk to Danny about optimizing your brake system. He's a true believer in stock Corvette brake systems.

I've been running them for almost ten years and never had an issue with the stock system. Then again I change the fluid every time I go to the track.

Richard Newton
Race Cars 360

ghoffman

Just the basics, pads, good lines and do your best to keep the caliper cool, with perhaps some DRM stainless steel pistons to reduce the heat transfer from the pads into the caliper. At that time, it would be prudent to replace the seals, they are very inexpensive from your Chevy store. Especially with the slide rail calipers, they get very soft with temperature and will spread. At 400F you have lost about 25% of the caliper's stiffness and if you find that 550 degree fluid is not enough, note that at 600F you have lost a full 50% of the aluminum's stiffness!

Gary04Z06

Carbotech pads, Xp10 front, XP8 rear, DRM bias spring for the master cylinder, high temp fluid, SS brake lines, new seals like was mentions.
Worked great for me on the track.
And run some brake ducts to the fronts....gotta keep the calipers cool.

astock165

I agree with everything Gary said except the perhaps about the DRM SST pistons. Those are a must.

The other thing you can do (that Gary actually showed me) is to cut a thin sheet of SST that is the same shape as the metal backing of the pads and put that on the back of the pad as another layer of insulation.

The biggest thing is keeping the calipers cool which is not a small task on a C4. It's easier if it's a dedicated track car since you can then remove the fog lights and use them as cooling ducts.

Fresh fluid is important too. I'd rather have fresh 400 deg fluid than old 600 deg fluid. Because of that I use the Valvoline synthetic fluid and have been very happy with it. I bleed the brakes before I go to every event (usually uses less than 1 qt).

Try things like this for a few event and if you're still not confident then you can investigate aftermarket stuff.

mikemiller68gs

I'm no expert, but I switched to C5 calipers in the front with Hawk HP Plus pads. I can go a ton deeper in to the corners than the stock calipers with HP plus pads i had before.

Mike

Sidney004

with all the above. If you upgrade wheels, the 18" wheels are the way to go because the increased clearance increases cooling. I run the Z06 18x10.5's and the open spoke design of the wheels is very good(compared to 17" sawblades.) I have also found that the stickier the tire, the less overheating the brakes experience because you don't use them as much. The real issue with the J55's is thermal capacity; if you simply want more braking power, sticky tires and high friction pads(I have used PFC 93's, 97's or Raybestos ST41's and they are very good.)

astock165

Did you change to C5 wheels up front?

redls1gto: keep in mind that in many cases the C5 calipers will not work with the sawblade wheels.

RedLS1GTO

I've looked at about a million different setups and 3 in particular stand out... anybody have any thoughts on these? I'm not running sawblades. I have 17x11 CCW classics all the way around.

Baer Claw Pro-Plus

http://www.summitracing.com/parts/BAE-4301348/

2 Different Wilwoods

http://www.summitracing.com/parts/WIL-1408337/

http://www.summitracing.com/parts/WIL-140-8337-DR/

John Shiels

GS calipers are not really very good. C5 calipers are better but I would get some Wilwoods from DRM for yu C4, You cannot have to much braking. It all comes down to $$$$$$$$$ and priorities and brakes are worth HP.

Some brake ducting and SRF is a must no matter what you are braking with.

ghoffman

1) Do not get holes in rotors.
2) If you get it from a big catalog place, good luck on follow up technical service, especially a year later.

The Wilwood clearance drawing is confusing to some, here is a pic of what the narrow SL6 looks like with a scale for reference.

mikemiller68gs

Yes, I switched to ZR1 style wheels at the same time.

Mike

BrianCunningham

The trouble with the C5 calipers, is that they're still slide rail calipers.

Wilwood makes a decent kit for our cars.

I really need to upgrade, I've already boiled my J55's

NOT A GOOD FEELING!

RedLS1GTO

OK, so I am more screwed up about this than before... does anybody know for sure whether any of the Wilwood kits will fit under a set of 17" ZR-1 offset wheels??? I have talked with John at CCW and he thinks the answer is no, however I have found a few different places that sell the kits that say they will fit with a stock ZR-1 wheel. John actually recommended that I go with C6 Z51 parts and was pretty sure they will fit. I have no doubt about those from a width point of view, but will those fit under a 17" wheel?

This is confusing

drivinhard

nope

CRAIG GELSTON

Danny gets GM calipers & parts for FREE, they SUCK!!! They might stop
a 3400lb race car going 150 once or twice, then you are playing with your life. I raced with that crap for 1 year and thanked god when I
could throw it in the dumpster. People have talked this to death a
million times on this forum, but at fast tracks like Road America, Atlanta
etc you will go thru 3 sets of front pads and 2 sets of rears in a weekend if you are going fast. The calipers get so hot it burns the paint off the wheels. Get something good or learn to recognize brake
failure before you total your car.
--Craig G.

ghoffman

Just stick a tape measure through the wheel until it touches the rotor face, and let us know the distance from there to the inside of the wheel spokes.

Sidney004

J55 Brake failure clues(probably applies to all PBR calipers)
1. pedal suddenly gets longer.
2. Pad Knockback(when you initially press on the pedal, no
resistance at first)
3. Smoke from the wheels and strange burning smell(ignite some
brake fluid and familiarize yourself with the smell.)

Those are the ones that I remember, I will update the list if any more come to mind.

John Shiels

Buy from DRM as Gary said call Jegs and others and you will get which won't be much help.

DRM knows C4 as they have been around forever.

Once I popped my C5 so I took the GS to the track. Passed 6-7 cars in a few laps and came in before I wrecked it those brakes are horrible for other than the street.

0Randy@DRM

There is two different Wilwood packages that I know about. The one right from Wilwood (SL6) and our package (GN3). Our package is much larger in size and requires the right wheel as we talked on the phone.

Randy