Disc brake conversion (70 Dart)
So it sounds like the basic paths are:
1) Rebuild with the parts I have (namely the spindles, using the rest as cores or throwaways) and then ordering new rotors/pads/bearings/tapered ball joint adapaters to match. Possible downside being using old tech for braking.
2) Ditch everything and order a kit from Wilwood (or similar manufacturer). Theoretical upside being everything is new and made with new tech. Downside is cost, debate over performance improvement, and may require getting new wheels/tires because the ones I have (both on the car now and the wider rims I have as well) won't fit.
Yup, you've got it. DoctorDiff will have all the parts you need to refurb/replace everything for the 73+ mopar brakes.
Also keep in mind your tire choice. If you're planning on running 15" wheels and BFG T/A's, you can put the biggest, most expensive brakes you can afford on there and it won't make a lick of difference, because you'll be traction limited before you're braking force limited. Doesn't matter how much clamp force you generate at the rotor if you can't put it to the ground.
And, the "new tech" thing isn't really accurate. The old Kelsey Hayes calipers that were used on the A-bodies from '70-'72 are actually 4 piston fixed calipers, just like the Wilwoods are. The biggest drawback to them isn't their braking performance, it's the scarcity of reproduction parts available to rebuild them.
I'm short on data? Oh, you mean your made up data. Nice try though.
I am and actual Mechanical Engineer in automotive.
You wouldn't understand the data anyway. You're not a real Mechanical Engineer. You just play one on this site.
I have tested every GM, Ford , Chrysler brake package available since 1996 and a lot of foreign OEM's. And a lot of brake packages suppliers try to pitch to OEM's. The Willwood's will work better reliably than the 40 year old tech. You seem to think the only thing that makes a brake package good is the size of the caliper piston... I doubt you could understand much else. You surely don't understand why even clamping force is a benefit.
Where's your data, saying they are junk? Oh, it's just your opinion.
The OP can choose to use the old brake system and most likely it will work fine for tooling around. It's his budget. He should plan on spending $500-700 when it's all said and done keeping the old design brakes if he wants to replace everything with new and rebuilds.
I'm not sure what your problem is. I don't "play" a Mechanical Engineer, and I wouldn't claim to be an ME anyway because it would be selling my education short. I hold an Aerospace Engineering degree from UCLA, which required me to take every class a ME would take and then Fluid Dynamics on top of that. I participated in Formula SAE for two years while I was in school, and then a couple of Aerospace competitions after that. I left the industry after college, but let's face it, brake calipers are not rocket science and I'm more than qualified to weigh in.
I would have no problem understanding any data you posted. Of course, you haven't posted any, not in any of your threads here. I know if I worked at a "suspension R&D shop" and had access to that kind of equipment I would be testing the crap out of all the stuff I was installing on my car, but I guess you don't bother.
And I certainly didn't "make up" any data. I used the specifications right off of Wilwood's site, as well as the dimensions I pulled off of an extra set of the Mopar 73+ calipers that I have. Hell I even linked to the specs.
I
DO understand why clamping force is a benefit. And I said in post #12 of this thread that multi-piston, fixed calipers are more efficient at transferring force at the piston into actual clamping force. They lose less of the generated force at the piston to flex and have more even pressures across the pads, both of which improve the clamping force. But, the Wilwood calipers in questions have a significant disadvantage because of their smaller pad and piston area. They generate less force at the piston than the Mopar calipers, that's just the reality of their piston area. I have NEVER argued that single piston sliding calipers are better than fixed multi-piston calipers
in general. But that's not what we're talking about, we're talking about two specific calipers, and while the Mopar calipers do have a simple, less efficient design they also have
a lot more piston area.
Now,
neither one of us knows for sure if the actual clamping force is better for the 73+ Mopar brakes or the Wilwoods. That number can't be calculated like the force generated at the pistons, it has to be measured because you have to know how much force is being lost to flex and uneven pad pressures. No caliper will transmit 100% of the force at the pistons to the rotors. The 73+ mopar calipers would need to lose an extra 24% of the generated force at the piston though, which is a lot, to end up having less clamp force than the Wilwoods we're talking about, because that's what the Wilwoods are giving up for piston area. Is it possible the Mopar calipers are losing that much force? Sure, it's
possible. But again, someone would actually have to
test it in order to know that for sure.
Now, if you've tested every OEM brake system available since 1996 why don't you actually test a set of 73+ Mopar calipers against the Wilwood Dynalite's and post up the actual clamp forces? You can easily do that if you have the equipment and experience you claim to have, and personally I'd LOVE to see the testing results. Even if they prove me wrong. At least then people can make an educated choice between the 73+ mopar calipers and the Wilwoods, weighing the cost of the Wilwoods against their actual performance.
