Disc brake conversion (70 Dart)

oi81b4uu812b4 said
That's a lot of write up for still not understanding even caliper clamping force on the rotor. I really don't care if a caliper clamps with 3000, 5000 or 10,000 pounds of force. If it ain't putting it down evenly, it's not efficient. And if it clamps the pads unevenly and can't do it repeatedly with consistency, it's inefficient. A smaller brake pad making parallel clamping contact with the rotor will always be more efficient than a large pad being clamped unevenly. I think you need to review the Statics, Dynamics and Materials classes you should have taken to earn your claimed Rocket Science degree.

Once again, you really don't understand why a multi piston caliper would have sequential piston sizes either.

And sorry a Aerospace Engineering degree from UCLA is about as good as a used piece of toilet paper. Probably why you're a firefighter instead.

But,everyone else posting on here would probably be happy just swapping to an old single piston Mopar caliper and it will meet the needs of their application. Even drum brakes stop great just driving around with, if they are driving like a little old lady, which is what 72bluNblu says he does, they will be fine. They just don't work the greatest when hot.

And yes, we have tested Willwood brakes here! They work great!

More name calling, still no facts. If you've tested them, post the data.

Yes, for the 10th time, calculated clamping force assumes 100% transmission to the rotor, which is not achieved by ANY caliper. But the Wilwoods are at a 24% total force disadvantage. That's not a small difference, and would mean the Mopar disk would need less than 80% efficient to match the Wilwoods for stopping power. Is that possible? Sure. I seriously doubt they're that bad though. Even if they really are that inefficient, it means they provide similar stopping power for significantly less money. Which makes them a perfectly valid choice in a comparison against the Wilwoods.

Again, post your data showing how much more efficient the Wilwoods are at putting clamp force to the rotor and prove your case. Or just keep calling me names, but I couldn't care less. Resorting to calling me names just shows you don't have any real data to support your case.

myduster360 said
When upgrading my 10" Drums it was a short leap to Wilwood. Here's my thought process.

For me, the deal braker going factory was:

having to buy spindles. If you need disk spindles, even a GREAT price for used spindles is at least $125 shipped---New off shore copies are $200 shipped

The TWENTY EXTRA POUNDS PER WHEEL OF UNSPRUNG WEIGHT.{I think its ridiculous to see guys spout off about how great their thousand dollar+ suspension mods are the bees knees in one post but also swear to their dying breath that the HEAVIEST disk brake setup available is pretty much always "the best"}

FABO group think dogma says just go to get factory stuff from Dr.Diff,,ok well that's over $550. Not really a steller deal and that's for reman calipers and Chinese knuckles,,,,meh
View attachment 1715197528

Even if you RockAuto most of the parts and find knuckles, the core charges and shipping still winds up the same price

Ok so over $550 for 38lb PER WHEEL worth of factory bits.
I'm building my Swinger with a 3.6L pentastar for better weight distribution and 40lb hanging off each knuckle wasn't siting well, especially for $550. WFT! For $150 more I could just get 100% brand new Wilwood.

View attachment 1715197527

But is the $150 difference worth it?!?!

Then I remembered an OLD Mopar Performance News(Dec 1993) article i read some 25years ago(found it tonight in the basement). The MP engineers were going on about their MP branded Wilwood disk kits--the SAME kits being discussed. The engineers claimed when a vehicle's UNSPRUNG weight is reduced, there's a 6:1 advantage per lb vs the same lb removed from SPRUNG weight.

"A acceptable rule of thumb in racing is that every pound of sprung weight you can remove from a vehicle will give you the performance equivalent of 6lb of sprung weight"

In the MPN article, they dropped 20lb PER WHEEL for the Wilwood vs 10.75" factory Disk. So the resultant drop in ET would be equivalent to reducing overall vehicle weight by 240lbs!(20+20 x 6)--a potential drop in 1/4 mile ET of .20s. Now isn't that about what ~10-15hp gets you? Not too shabby side benefit for Fen BRAKES!

This would be ON TOP OF all the benefits of lighter wheel weight has on handling, which is 99% of the time why unsprung weight is reduced. So yeah WILWOOD!

My Wilwoods are 24.4lb total with the lighter weight 10" drum knuckle + LBJ.
The 10" Drums, Knuckle + LBJ weighed in at 35lb
The Stock 10-3/4" disks are ~38lb WITHOUT the knuckle OR LBJ, so maybe 45-48lb? if included.

View attachment 1715197551

Oh one more thing,,,that super scary 500lbf deficit the Wilwoods have compared to the "stock" disks,,it only takes an extra 15lb of foot pressure to make up the difference--about 2 toes worth lol

myduster360 said
2nd source on the 6:1 performance advantage comes from Olaf Manthey, Porsche race team owner/driver.

Olaf Manthey: “Removing 33 pounds of unsprung weight at the wheels is equivalent to losing 198 pounds from the body of the car, as a 1:6 factor has to be applied when the car is moving and that weight becomes mass. In fact, we are conservative with the 1:6 ratio, as Porsche considers it to be 1:7"

- You quoted a sale price on the Wilwoods. Nice if you can get it, but you're not comparing straight across

- The original poster of this thread doesn't need spindles, he already has them for the '73+ disks.

- Sure, you can arbitrarily add more brake line pressure to just the Wilwoods. But if you compare apples to apples using the same brake line pressure, the 73+ Mopar calipers still have more clamp force. If you're willing to increase the line pressure, you can do it for the Mopar calipers too. On that note, the 70 lb applied pedal force I used is already kinda high. Most newer cars with boosted systems use a pedal input of about 45 lbs. Maximum pedal pressure is usually assumed to be around 85 lbs, but that's not a sustainable force for most people. 70 lbs is typical for performance type vehicles, where it's assumed the driver is in decent physical shape. You can assume an 85 lb input force, but you may not be able to generate that all the time, which means you're not putting that force to the rotors all the time either.

- Yes, removing unsprung weight is always an advantage in performance. But, you're talking about racing and ET's, not brake force. If you want to spend cubic dollars to save a few tenths at the track, awesome, buy Wilwoods. But not everyone here is talking about racing, they're talking about having reliable brakes on the street.