Lightweight Brake Drums

[cudabob496]

Anyone know of any aluminum or lightweight brake drums that would fit my 72Cuda. Maybe I could machine a few pounds off the existing ones?

[stickshifted]

Originally Posted by cudabob496

Anyone know of any aluminum or lightweight brake drums that would fit my 72Cuda. Maybe I could machine a few pounds off the existing ones?

dont do it. think about it this way: muscle cars already have very lightweight rears compared to the front's. why would you wanna reduce weight there?

i could see it if you had drums in front and wanted to make those lighter, but i say leave those heavy ones on the rear drums where they belong!

[Ray Bell]

I frequently reel at some responses on fora like this...

So many people seem so scared to let people try things they might consider to have an outside chance (it seems) won't be good or might incur some minute risk.

But this time I'd agree with them. If you plant to use the brakes as they are normally used, I wouldn't recommend cutting any significant weight off the drums.

[DJM]

Most if not all brake drums have a maximum cut stamped on them . This is stamped there for safety reasons. Any more cut than this reduced the integrety of the drum.

[JVMopar]

Instead of trying to cut weight off your drums you should think of going to smaller diameter brakes. Moving the weight in an inch or two towards the center line of the axle will give you more of a benifit than just taking some weight off of larger drums.

I don't know what your reasoning is, but I have to agree these cars weren't made to stop well. And degreasing the effeciency of the original braking system is probably dangerous.

[stickshifted]

Originally Posted by Ray Bell

I frequently reel at some responses on fora like this...

So many people seem so scared to let people try things they might consider to have an outside chance (it seems) won't be good or might incur some minute risk.

But this time I'd agree with them. If you plant to use the brakes as they are normally used, I wouldn't recommend cutting any significant weight off the drums.

haha. lol and i am usually one of those people who's always comming up wit crazy ideas...

but when your dealing with muscle cars, huge engine in front, and a rear end that likes to lose traction, the more weight you can geton that back end, the better.

now if he were talking about front drum brakes, ive always wondered this - if they can have drilled and slotted rotors, why not drilled and slotted drums? or at least drilled?

and the other reason why you can only turn a drum so far, is that cutting too deep will make the diameter so large the shoes will be too small for them and dont engage them properly. they will squeal and they wont stop properly if you do that.

i say this. add some weight to your back end. relocate your battery to the rear if you can.

[stickshifted]

Originally Posted by Badassington

Yes, the rears are lighter.

Maybe work on getting the frontend lighter, drilled rotors and aluminum calipers?

ehhh. i dont think id trust aluminum calipers...

could do a carbon fiber hood.....that would save hella weight

[stickshifted]

Originally Posted by Badassington

Well I understand but look at all the aluminum used in engine parts with rpm and up to 700 psi loads and then the aluminum caliper used on other factory cars for decades.
no big.

well aluminum forged rods might be good for a racing engine, but they're not gonna last 150,000 miles like a good forged steel rod will.

hmm. i learned something new today. i wasnt aware that many cars used aluminum calipers. all the cars ive dont brake work on had cast iron ones...

[aarracer]

Get a disk brake kit for the rear!

[DJM]

Although I will get a lot of negatives on this I willstand by the fact that drum brakes will stop you as quick or quicker than disk brake until under constant braking repeated braking heat up to the fadding point. This is a main point in favor of disk brakes is the fade resistance. Drums under hard braking will have more of a tendancy to lock up the wheels due to the shoes actually tightening themelves into the drum by turninig into the rotation of the drum. A thing that disk systems cannot do so are not prone to locking up.

[dodger1]

What DJM said, plus the fact that, the harder you hit the brakes, the front brakes take a higher proportion of the braking effort due to weight transfer, which means the rear drums don't need to contribute much during a hard stop. (Which is why proportioning valves are an integral part of disc/drum set-ups) Taxi/copcar rear brakes had larger drums, but I think that's because the vast majority of braking in those applications were low-speed, low-energy stops and the rears took more of the load than a high-speed stop would.

[cudabob496]

Buicks used aluminum brake drums, and they are a popular switch.
Obviously the aluminum brake drum had a steel inner lining.
I could shed 10 pounds per rear wheel with disc brakes, but only if they do not have an emergency brake feature. Otherwise the weights are about the same.
Already went to lightweight discs in the front, and skinny front tires, and lighweight wheels. That combo shed 40 pounds per each front wheel!!!!
Rear brakes only do about 30% of the braking anyway. I would go to Wilwood rear drag lites, but the law says I need an emergency brake.
Smaller rear drum brakes is a thought!
I would imagine that even without rear brakes at all, the front disc brakes would stop the car in a decent distance (not that I'm gonn try it). Probably the same distance as the original front and rear drum brakes combined.

[cudabob496]

Originally Posted by stickshifted

dont do it. think about it this way: muscle cars already have very lightweight rears compared to the front's. why would you wanna reduce weight there?

i could see it if you had drums in front and wanted to make those lighter, but i say leave those heavy ones on the rear drums where they belong!

Heavy wheels, front or rear, equal SLOW!!

[cudabob496]

Originally Posted by DJM

Most if not all brake drums have a maximum cut stamped on them . This is stamped there for safety reasons. Any more cut than this reduced the integrety of the drum.

There is still probably a significant safety margin before failure, and the front brakes do 70% of the cars braking as well.

[cudabob496]

Originally Posted by JVMopar

Instead of trying to cut weight off your drums you should think of going to smaller diameter brakes. Moving the weight in an inch or two towards the center line of the axle will give you more of a benifit than just taking some weight off of larger drums.

I don't know what your reasoning is, but I have to agree these cars weren't made to stop well. And degreasing the effeciency of the original braking system is probably dangerous.

Reasoning simple, less unsprung rotating weight means car is faster.

[aarracer]

cudabob496

You could also narrow the rearend and get a more offset rim and shed more than a few pounds of unsprung weight that way?

[dodger1]

Older Subaru's (DL, GL, Loyale) had front discs with the park brake cable acting directly on the calipers. Light weight, and a built-in parking brake. Wonder what it would take to adapt them? A disc-brake hub for starters, obviously.

[cudabob496]

Originally Posted by dodger1

Older Subaru's (DL, GL, Loyale) had front discs with the park brake cable acting directly on the calipers. Light weight, and a built-in parking brake. Wonder what it would take to adapt them? A disc-brake hub for starters, obviously.

http://www.tolomatic.com/products/it...fm?tree_id=184

[cudabob496]

Just found out you can lose 10 pounds per rear wheel by going from 11 inch to 10 inch drums.

[cudabob496]

Originally Posted by aarracer

cudabob496

You could also narrow the rearend and get a more offset rim and shed more than a few pounds of unsprung weight that way?

Good point!

[JVMopar]

Now get a set of 9" you could loose a couple of more lbs.

[cageman]

Drums are lighter than discs.
I had a camaro that had alum drums in the rear, nothing wrong with them.
You could drill holes in the drums, and cut most of the backing plate off. get rid of the ebrake and cables. Probably as light as it will get. Look at an old nascar car form the late 60's to 70's, that is how they did it. I seen a 68 charger once that was ex nascar and it had no bcaking plates at all, just a little mount for the wheel cylinder and brake shoes to mount to, real light weight.

[aarracer]

And I know of one Nascar driver for sure, and there are probably more that died due to drum brake failure.

[DJM]

Originally Posted by aarracer

And I know of one Nascar driver for sure, and there are probably more that died due to drum brake failure.

If you are referring to my post above you will not that I stated that drum brakes will actually stop you as quick or quicker than the disc set up as long as they are not used to the point of getting HOT and then they are very prone to severe fade and failure. They will in fact (good or bad at times depending on the situation) lock up the brakes as the shoes will actually turn themselves into the drum self tightening.
But for constant repeated useage as in circle racing, heavy traffic on hot days heating up the brakes, long steep grades the discs will be better as they are very unlikly to fade out on you. Any place the brakes are used without a chance to cool down between usage disc brakes get the the +++.

[aarracer]

DJM

Not reeferring to your post, but adding a little safety belt knowledge to this particular subject. Also when racing or in any very high performance brake component applications were extreme temperatures and very high speeds are the norm, it is a good idea to have the components magnafluxed for invisible cracks prior to each useage.

[DJM]

Originally Posted by aarracer

DJM

Not reeferring to your post, but adding a little safety belt knowledge to this particular subject. Also when racing or in any very high performance brake component applications were extreme temperatures and very high speeds are the norm, it is a good idea to have the components magnafluxed for invisible cracks prior to each useage.

I fully agree. When you are racing the last thing you need is brake failure.
I do know some stock class drag racers that will run drums rather than disc because of weight with no problems but they aren't on the brakes constantly as they would be in going in a circle. But they can't run after market.

[cudabob496]

And 99% of us are just puttin around on the street!

[cudabob496]

Heres a question: My cuda weighs about 3250 pounds. What if I don't have brakes on the rear wheels at all. Will the Wilwood disc brakes on the front do an adequate stopping job. (Don't have a heart attack. I'm not saying I'm gonna do this. Just speculating)

[aarracer]

Originally Posted by cudabob496

And 99% of us are just puttin around on the street!

Then why bother at all with lighter brakes?

[ehostler]

With your monster of a 496, I would recommend converting to 4 wheel disc brakes. They are a lot lighter and will do a much better job of stopping that beast.