my IROC has the aluminum drum rears and i was wondering how much braking power is improved by installing stock rear IROC discs. i found someone with a posi rear end w/discs for a decent price. has anyone converted over? if so, do i need to purchase any extra hardware to hook up the parking brakes?
thanks for your input

 

I cant imagine drum to disc would be worth it. if I slam on my brakes, my rear drums will lock up pretty quickly...

 

Sorry but this is exactly what you don't want them to do.

Drum brakes work with little "feel". Converting to disc will give you better feel or sweet spot. This is the range from when the brakes are first applied- to when they initially lock. You will have better pedal control with disc brakes and they will not fade as easily.

My camaro is the third vehicle I've owned that I will have converted to 4-wheel disc. Have almost everything sitting in the garage to do this, just waiting to get Spohn subframe connectors and install them first before anything else.

I will be facing the same hurdle with the e-brake. Just haven't checked into it that far yet. Will worry about that after eveything is in. Along with the combo valve. But I'm probably not going to reuse the existing front discs so this will be trial and error.

 

I think that the only part you'll need outside of the actual brake components will be the E brake cable, and possibly just the aft end of it.

 

ok maybe i can help, my iroc came factory with a 3.45 9-bolt disc setup, when the pinion gear spit a tooth threw the cover, i put in a 10-bolt with 3.73 richmonds in it. and drums, when i did this , i changed the master cylinder and prop valve, and the rear cables.
when the pinion bearings on this rear went south i decided to install another rear end i had sitting around, a 10-bolt 3.23 with discs, once again i changed the master cylinder and prop valve, as well as the e-brake cables. so i now have discs, on all 4 again.

when i get enough money, ill fix the 9-bolt,

as for the difference, my brakes havent completely bedded in yet, but the difference is definitely noticeable.

my next mods will include cross drilled rotors for all 4 , as well as braided steel brake hoses.

if u have any questions shoot me an e-mail or something, ive done drum to disc and disc to drum swaps a few times, and i know the procedure pretty well.

Matt

 

On a third gen I really haven't felt a huge difference between disc and drum setups; though I'm sure the numbers would show a difference. I know though that it takes more power to turn disc brakes over drums. There are weight numbers in the Tech Data section that show how much heavier discs are than drums.

 

I did the conversion on an 85 IROC several years ago. You'll require new e-brake cables for sure, and as I recall (at least for my application) a proportioning/master cyclinder.

JamesC

 

So wait, does it really make a difference?

 

Considering the time, effort, and money to do the swap, probably not.

JamesC

 

There's your answer.

 

Of course it makes a difference!!

It is the difference between you replacing your front end or simply wiping your brow and saying "That was a close one"

ALL of my Firebirds have disk rears. If drums were so great then, new performace cars today would still have them.

Do the swap, it is worth it.

 

As always, it depends on how you drive and whether or
not your system works in the first place...

Assuming your disk/drum system is working properly

1. Autocrossing...
No difference, 1 minute runs not long enough

2. Street
No difference, Same deal you don't use the brakes
in a manner that means anything

3. SOLOII/Road racing
Yes, the brakes will change characteristics much less
over the 15 minutes or so of a heat

4. Mountain roads
Yes same reason

5. Drag racing
It is not unreasonable to see a loss here
The aluminum drum setup is often lighter than a lot
of disc setups. And it is light where it is "most" important
(rotating weight)

Of course if its broken...
Any change will likely appear to be an improvement