Chevelle disc brakes

[qwk406]

Hi folks,

I'm looking to improve the braking in my '69 Chevelle, I have stock front disc setup and at this point in time am keeping my 15" rally's. The car is street driven and currently upgrading the suspension with front SPC adjustable UCA's, LCA's and tall Howe BJ's. I do not want to put bigger wheels on it with "big brakes" just yet, as there are more important upgrades that take precedence.

Any advice/experience with a particular company as far as rotor's, calipers and pads? I've seen mention of a 12" rotor with a wilwood D52 caliper, anyone using a setup that has helped braking without making major mods? Use of factory parts from another year vehicle maybe?

Is drilled/slotted, slotted, just drilled really help it perform better on the street? I know it can benefit during race events, but this isn't a race car. I've also heard of drilled rotors cracking.

Is a dual piston caliper really better than single?

I try to use the best quality parts that are readily available, one thing I've learned in 36 years of driving this car everywhere (power tour, 150 mile trips to cape may, wildwood and further to OC Maryland), is that there is nothing worse than needing a simple part on a road trip and not being able to get a replacement at a local parts store because it's aftermarket.

Thanks for the advice.

[monkey]

I used NAPA prem pads and rotors and like them. I also installed hydroboost because I don't make vac.

[Hotwire]

A hydroboost setup will give you a better pedal, but as far as you brake hardware, wait to upgrade when you have bigger wheels. Spending money on a system to fit your wheels is wasted in my opinion.

As monkey above said, upgrade your pads to a better compound, install a hydroboost booster, check your rubber lines and make sure they're not swelling/cracked. Then just enjoy what you have until you bump up wheel sizes.

Whatever you have now, if you can lock up the tires, won't change that fact. I just went from 70 chevelle discs and stock rear drums to 2000 Z28 setup (LS1 big brake upgrade). It's awesome, but now my tires are the limiting factor.

Another thing you can do to adjust your rear drums to get the best performance out of them is find an empty street. Put the car in reverse and get up a decent amount of speed, then jab the brakes, let off, jab, etc until you come to a stop. Now drive forward and do a quick stop. If the rear of the car lifts, run the reverse procedure again. What you're doing is shocking the rear "auto" adjustment screws into action and adjusting the shoes so that the drums work as advertised. I would do this before any long trip or towing with my trucks/cars to make sure I had 100% brake capacity. It really does make a difference.

[jetmech442]

Hey qwk406,
So when I first started down this path about 10 years ago(geeeze really?), I got the CPP disc brake conversion kit, with iron D52's up front,and Gm metric "Cadillac" calipers(also known as D154's) with the ebrake in back. I after two years I swapped the fronts with Wilwood D52's because bleeding is easier and also looks. The D52 caliper actually has great piston area. The twin pistons in the wilwoods keep the same total area(well they loose a tiny fraction), so there's no force upgrade with those. You'd be hard pressed to find a caliper with that much area for our cars. I'm sure even pad distribution on the wilwood 2 piston helps, but not that I can tell.

Drilled/slotted looks cool, no doubt, I ran them for almost ten years. Supposedly the slotted can help with pad wipe and help initial brake bite. Drilled can crack, sure, I never ever got mine hot enough to experience cracking. Even if I did, the rotors are cheap enough to replace. I say go with what you like. If your street or autox, you won't miss that thermal mass being removed from the drilling. I would recommend the non friction surfaces ecoated so they don't rust so doggone easy after a car wash.

I just recently went to Tobins hubs from Kore3, 14'' rotors and Wilwood Aero6 calipers. I did this only because routing air ducts to the brakes is really compromised, and I plan to road course my 442 more and more. If there was a known solution for a 12'' rotor and keep my D52's, I would have. Switching to the Aero6 calipers actually lost me over half my piston area, so I had to drop my master cylinder bore from 1.25 to 1'' to keep my force the same. So braking performance will be roughly the same since I am still using wilwood BP20 pads. I don't want to go lower on MC bore because I think pedal travel is too much and heal toe gets harder with more brake pedal travel.

I think the D52's and D154 are great calipers(in wilwood form). They package well in 15'' wheels with 11+ inch rotors. If your looking for more stopping power, an aggressive street pad should make a big difference. Everyone's got their preference. I tend to use companies that publish their friction curves and am weary of companies that claim "excellent cold AND track use!" lol.

Hope this helps. -Scott


I'll briefly say the cadillac calipers with the ebrake are pure trash. I never got them working right, or adjusted properly and not for lack of trying and learning. 8 years go by and I never really had a firm pedal. two years ago I replaced them with wilwood D154's without an ebrake. instant hard pedal and driving becomes much more enjoyable. There might be someone out there that knows how to get the cadillac calipers to work and likes them, but I was never able to find that person.

[Skip Fix]

"If there was a known solution for a 12'' rotor and keep my D52's, I would have."
1LE setup from a B body spindle.

The rear Caddy/79-81Trans Am calipers are a pain as the ratchet mechanism often quits working either constantly retracting it too much or keeping it too tight. The ones on my &* TA have worked great for a long time had one gone bad off and on since I added them back in the late 80s. I do credit the silicon DOT5 for keeping the ratchets working. And it has a good pedal stopping at 125 at the drag strip.
D614 Impala SS pads are a little bigger and fit D52 calipers also.

Mt Camaro/Pontiac drag car has "plain" metric D154s on the rear to not have to worry about the ratchet though.So far unimpressed with the Wilwood Dynalites on the front fro drag and had to replace a set for bad pedal after only 15 runs and a little street miles.