Disc brake conversion (70 Dart)

72bluNblu said
See, here's the best part. I don't say so. The math says so, based on specs provided by Wilwood and Mopar. Braking force is just physics and math, and based on the numbers from Wilwood, the Wilwood brake kits you can get for A-bodies that fit 15" rims aren't better than the 73+ Mopar disks at generating brake force. The '73 Mopar brakes have more piston area, more pad area, and just as much rotor diameter.

Are the Wilwood brakes shinier, fancier, few pounds lighter, sure. But you're just spending more money for something that doesn't actually create more braking force than the '73 Mopar brakes do. And isn't that what brakes are supposed to do? Create more braking force?

Now, if you think I've done the math wrong or used the wrong numbers, by all means lets see the right info. Let's see the proof. But the endless "Wilwood is better than everything factory" isn't going to cut it, you have to come up with evidence now.

Actually you didn't do any math. You just looked up piston area. Which shows your limited knowledge of how brake calipers are designed.

The problem with single piston brake calipers, slides and bushing mounts, is under braking the pads can flex and produce uneven friction coupling on the face of the brake rotor. Which causes uneven wear or tapering,noise, vibration; or all of those.. And if that's the case, it doesn't really matter what size the pads are. If they have a tendency to not perform properly, your braking force calculations can really only use the diameter of the caliper piston and not the pad area. Yes, the larger pad can absorb more initial thermal heat shock, but that's about it. The reason why multi piston brake calipers sometimes don't have large brake pads is because the manufactures are trying to eliminate pad flex that produces uneven wear,pad tapering and heat. Plus if they can achieve a more desirable "even" brake pad wear with a multi piston design and a smaller pad. The benefits of a larger brake pad's thermal shock heat absorbing is really has no benefit if the brake pad is being pushed into the rotor unevenly or the pad flexes even just a little outside the caliper piston diameter.

And usually modern multi piston calipers have more aggressive piston seals to pull the pads back off the rotors when the driver releases the brake pedal. Why? To produce less heat because your pad is dragging on the rotor after braking. Dummy.

Those old designed brake calipers when worn just don't perform great, they get by. They flex, they quit sliding, rotating on worn parts and a whole bunch of other problems.

I have awesome pictures of Brembo and Baer testing prototype ZR1 and CTS-V calipers over base model calipers on our 500 HP brake dyno at work. You can't beat the even clamping force of a multi-piston caliper and it's repeatability. Even under extreme temperatures. That's a fact.

Willwood, Baer, Brembo all base the number of pistons, piston size and pad size based of vehicle weight and what stopping force is needed. Usually you don't need 6 or 8 piston calipers on and old car. But those do produce a more even clamping force and better wear when designed for that application.