Is a Disc Brake Conversion Worth It?

[lewtot184]

from my experience a firm NO.

 

[Rusty knuckles]

I considered doing a disk conversion on my Charger. Then I took it auto crossing with drums. I can skid the tires just fine and don't get brake fade. So I decided that I didn't really see the point in switching. I'm sure the disks would have more "feel" with disks. But once tires slide there isn't any more stopping power.

 

[funknut]

When I first got my car it had manual drums. I had them rebuilt and braking performance improved, but still unimpressive. A while later I converted to hydroboost, Wilwood MC and front discs and it was a massive improvement. Braking performance was equivalent to both of our modern daily driven vehicles.

I did end up adding rear discs a bit later and can say they didn't contribute much of a change.

A while later, the hydroboost unit developed some problems, so I took it out and changed to manual brakes with a smaller bore MC and it was a huge step back. I'll be rebuilding and reinstalling the hydroboost unit this summer. Can't wait!

 

[Ron H]

Amazing how many different experiences and/or takes folks have with disk/drums. After my conversion, it takes a bit to lock the wheels on gravel; but they will lock. The stopping action was a noticeable difference. I’m not sure if I needed the extra hassles I encountered adding power. I could stop my ride even with the manual brakes – my leg power was fine, so far. Did think more than twice about this as members were saying they did fine with manual disks.

 

[69ChargerR/TSE]

11" drums?
I am going to use these shoes.

1969/DODGE/CHARGER w/11" Drums/Porterfield Brakes - Porterfield Brakes

1969/DODGE/CHARGER w/11" Drums/Porterfield Brakes - Porterfield Brakes

porterfield-brakes.com

 

[1 MEAN66]

I also change to disc/stock drum on my 66. There are a lot of articles on cheap (inexpensive) conversions in some of the now gone Mopar Magazines. If you can't find on line let me know I can try to send ya a copy. I forget what years switch to what years (that info is in the articles) but I was running low-mid tens @ 125-129. And about the third pass the 10" stock drums were not happy!!! So for about $100 I got a set of spindles from a 74 A-body Dart (10' discs) put them on, with new - pads, rotors, bearings, seals, and flex hoses ( all A body OE parts) which is all available at local parts store. Also change to a 2 bowl master ( 15/16' bore manual ) and of course made up the new brake lines I keep the 10" drums in the rear! I did use Wilwood adjustable proportion valve. The spindles have the same dimensions (angles at the ball joints, height, etc.) so all the front end parts like each other and work a normal. The "control" of the stop, beside the ability to not fade after repeated stops is what you are after. Being able to skid the tires while braking is NOT the key!!! Skidding tires have less traction/control then those that are rolling!!!!!!! That is 50s-60s Tom McCahill (and at that time) stupid road testing. I am sure that Wilwood systems would be even better, But the cost is far greater, and even a day at the Drag strip I never had any problems! Just "food for thought".

 

[blue69runner]

Change up too front disc from Wilwood. Running Dot 5 fluid. They are proud of the that fluid. LOL. But very happy with the stopping power. Got rid of that front end shaking when stopping. Best move I could have made. Could not find good new brake drums. They were egg shaped to say the least and had turned them twice and still not perfectly round. So that is when I decided to switch to disc on the front.

 

[Moparfever65]

Drums are fine until you go through water. Only need front discs.

 

[Demonic]

Rear disc is overkill unless you're doing heavy autocrossing or really want that slight decrease in stopping distance. Maybe if you're daily driving a 69 Hemi Road Runner.

I experienced drum fade on my Charger years ago, the second quick stop from 45-50 mph. Pedal was hard as a rock. Swapped to A body disc and never looked back A huge improvement.

 

[451Mopar]

Front disc is a pretty easy upgrade.
Rear disc is more of a job, and not worth the hassle on a street car.
On the rear disc setup, they want you to:
1. use the Green axle bearings
2. mount/weld brake line hose mounting tabs to the axle.
3. make your own hard lines to the brake hoses
4. if they even have an emergency brake option, its unlikely the E-brake cables will be the correct length.
5. depending on the kit (Wilwood), the rotors might not be hub-centric requiring hub adaptors for the rotors.

 

[Kern Dog]

What some people don't realize is that REAR disc brakes, when properly sourced and thought out, allow for more precise braking up to the point of lock up. This is known as "Thresh-hold Braking".
Drum brakes work based on "self energizing" which acts almost like a booster within the assembly. As the shoes dig in, they bite in an exponential manner. Twice your normal pedal pressure may result in 4 times the reaction at the drum brakes. DISC brakes are linear. 1 for 1. It is easier to modulate.
I agree that skidding brakes are less effective than a tire that is rolling BUT if you can't get the tires to skid at all, you are not reaching the potential of the brakes. You should be able to skid but then learn where that point IS and then use the brakes to just BELOW that point.
Think of having the ability to lift something heavy....You want to have more energy than you need so you can have control instead of using everything you have.....which may not be enough.

 

[Stonehengeheel]

I've converted both my cars to front discs.

It's my opinion that there is no need to change to rear discs.

This.