Disc brake conversion (70 Dart)

66fs said
I know most of what you say, and agree with what you are saying, the problem I have is in your calculations on the spread sheets. 1. You do not account for the friction from the opposite pad in a floating caliper. 2. The braking diameters are incorrect unless I am missing something. I have been driving fast A Bodies for 45 years and unless the is a failure, stuck pistons, calipers frozen, glazed pads or rotors, all of the OEM disc systems work fine. To me the refinements are in the different diameter pistons to evenly apply pressure to the pads, higher friction materials, larger OD rotors to get a better moment arm, thicker rotors and pad materials to dissipate the heat better. Not raelly new technology I can't just upgrade to ant system I have. As for the floating calipers, I'm sure they are not optimum but can really get the job done. I have not seen pad wear problems in any of my cars, including an 96 ACR Neon with 250,000 street miles. I do not road race, so I am not standing on my brakes and trashing a set of pads, rotors, and at least 1 set of race tires every weekend. I usually replace pads every 100,000 miles and Rotors every 200,000 miles.

I did road race a 400 HP Forward Motion 2.2 Shelby Charger in the late 80’s early 90’s and later a Neon, the stock brakes sucked after both cars had marginal upgrades and weren’t on the either car very long. Pads even disintegrated outside the piston diameter due to flex/heat on several manufacturer brands. You can’t put the heat into the metal backers on the pads without them bending under a single piston. And there was a lot of tapered worn pads and shuddering. And with race pads that produce high dust, the floating calipers stop floating. On street cars the old single pistons work for most people just fine. I doubt many people push their old floaters very hard.

Sounds like you are pretty easy on your brakes. Most people here are. I doubt mine last 1/4 of those miles on any car I have.

I did have a rare thing happen once. I had a cast iron rear caliper brake in half and the piston fell out approaching a turn at about 90 mph. Most likely though that came from a few months earlier when the car was pulled out of a trap backwards with a strap and maybe a poor casting.