z28cdoyle

I designed a new front brake setup after I gave up on the LS1s (road race car=caliper spread, insanely high cost for racing brake pads for LS1 calipers). I decided to return to the stock caliper (cheaper brake pads, no caliper spread) and build a bracket to move it further away from the spindle so I could still use a 12" rotor. I experimented with different rotors and found the C4 (non HD) front rotor would work. I'm using a 1990 vette rotor. Of course the C4 rotor is thinner than the stock thirgen rotor so I made a spacer for the inboard pad to make up for the thinner rotor. This worked well since I had some trouble with the stock calipers bending the innner brake pad backing plate under heavy braking on the race track. I have a 5/16" spacer behind the inboard pad now... no more pad distortion.

I'm using the same hubs I made for the LS1s with extra length wheel studs.

My caliper bracket consists of a modified factory rear disc brake bracket (J65 Delco Moraine cast iron calipers) welded to a seperate bracket I fabricated. This allows me to use the stock caliper pins and have the "fingers" on the top of the factory disc brake bracket to brace the caliper. This is very important since the caliper pins do not absorb braking forces. They only locate the caliper in relation to the rotor and allow it to slide as brake pads wear. The factory disc bracket keeps the caliper from turning when the brakes are appiled so it absorbs the braking force.

A nice thing about this package is that the centering of the brake caliper over the rotor is not affected by the bracket thickness like on the LS1 setup. This means that the adapter bracket welded to the factory disc bracket can be as thick as you want it to be. I'm using a 5/16" thick bracket. The factory disc bracket is 1/4" thick.

I cut the spindles similar to the 1LE, C4, C5, LS1 setups but left an extension to fit into an opening cut in the adapter bracket. I think this makes the bracket stronger than any of the other setups. These extensions absorb rotating force transferred to the bracket from the caliper/rotor in addition to the two 1/2-13 grade 8 bolts holding the bracket to the spindles like the other setups use.

Here are some photos of this "Cor-maro" brake setup.

z28cdoyle

Another photo of the modified spindle.

z28cdoyle

The adapter bracket welded to the factory disc bracket. The slots engage the extensions left on the spindles.

z28cdoyle

The front of the bracket.

z28cdoyle

The bracket, spindle and hub.

z28cdoyle

Here's what it looks like with the rotor on.

z28cdoyle

Now for the caliper.

z28cdoyle

The spacer behind the inboard brake pad. It is visible in the last photo as well. The "nub" on the back of the inboard brake pad has to be ground off or you have to drill a hole in the spacer so the pad sits flat on the spacer.

z28cdoyle

Finally, a stock Camaro caliper clamping a 12" C4 rotor.

z28cdoyle

What it looks like from behind.

ebmiller88

iTrader: (7)

Now THAT is different, something to consider.. Nice job!

Ed

Mongoose

iTrader: (2)

Why go through all that fab work when a C4 conversion with pBR calipers is readily availableand cost effective?

DuronClocker

iTrader: (1)

That caliper looks tiny on that rotor I wonder if maybe a C4HD rotor would have been the better option because you may have not needed the shim then (since its thicker), and then you could have made the caliper look almost non-existent!

Its definitely something interesting, and I know the small 10.5" rotor holds back the stock brakes pretty bad. I was curious as to how decent the stock calipers were though when I noticed how huge the pistons are. They were huge compared to the pistons in my C4HD brakes. I don't see them working all that well for a road-race car. The iron just doesn't dissipate heat as quickly as aluminum could. I think you should've just swapped to C4 calipers since you already had some of the stuff. It just would've been the cost of new calipers and rotors since you can make your own brackets.

I think if I ever do it over again, I'd go with C5 brakes, but I won't do that until I know for sure I won't have to drive my car in the winter again. My winter tires are 16s and wouldn't fit over C5 calipers.

Gladstoneiroc

iTrader: (1)

That's pretty neat. I think putting the C4HD rotors would be more worth wild. How about C5 rotors with the delco-marines in the rear next? Also getting some track testing with these, I wish I could have some in-car experience with these.

z28cdoyle

I ruled out the C4 brakes because of their small pistons and the need for heavy brake pedal pressure to get them to work. This was just not something I wanted in a brake system.

Quite honestly, I don't know much about the C4HD system so I never considered it. How is it different than the C4 non HD?

The spacer behind the inner brake pad is also stiffening the brake pad backing plate. For anyone who thinks the problem with the stock caliper is inadequate clamping force, you should see what's left of my brake pads. I have had trouble with the inner brake pad bending (bowing towards the rotor where the piston pushes it). The spacer eliminated this problem. However, the caliper crushed the outer brake pad beyond belief.

I will try a different brake pad with more bite that can take more heat. If that doesn't work then I am through "playing games". I have been looking at racing calipers from Wilwood, Outlaw, and JFZ. These guys make calipers that stop 3500lb, 800hp Nextel Cup cars. I'm sure they can stop my car.

ebmiller88

iTrader: (7)

The HDs give you a 13" x 1.1" rotor and C4 calipers which are essentially the same as 1LE calipers. I run these on the RS and they're great, even with my drums in the back.

Ed