I thought all IROCs came with 4 wheel disc brakes? I looked at a car yesterday that was a pretty nice 87 iroc but it did not have a serpintine setup or rear disc brakes both of which were a bummer. Did GM make IROCs without 4 wheel disc and serpentine setups? Also why does everyone swap the rears with drums instead of just putting on disc? This IROC had aftermarket gears and an auburn pro posi in it so if I bought it I would rather just put the disc on that rear instead of swaping everything over and re-shiming it, can it be done?

 

Unless you're putting on an aftermarket rear disc conversion kit, you'll have to do some fabricating with the axle flanges. They're different between a drum axle and disc axle.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

As pathetic as this is, I have never seen a drum brake live axel, I have only worked on
disc camaros. That makes sense though. So if I was to swap out the axels then the rest can be bolted up? Also, did all IROCs come with 4 wheel disc brakes?

 

Not all IROCs came with four wheel discs. It was an option(1LE or G92?). I do believe that all Borg rears came with discs. Also if you just switch axles, what are you going to mount the calipers to, how are you going to supply more pressure(discs need way more pressure than drums)? I'm not saying it's impossible, just a little more work. The reason most people like the drums, is because they don't drag like discs. Correct me if I'm wrong.

 

Does the extra rotating mass and the total inconvenience of changing shoes outweigh the benefits of disc though? If their is not a big difference in stopping power then I can live with drums. On my axel housing I have on my 92 1LE their is a mount that bolts onto the axel housing which bolts onto the caliper, I was hoping a drum rear end would use that same bolt method so all you would have to do is swap the mount, caliper, rotor, and lines and be set, but I guess it does not work like that.

[This message has been edited by UVA3rdGen (edited August 09, 2001).]

[This message has been edited by UVA3rdGen (edited August 09, 2001).]

 

UVA-

You may want to put some thought into going to rear disc's on a thirdgen. There is a post around here about the rear disc setup being defective from GM and how GM does not offer all the parts anymore to fix it. I have a '88 IROC w/rear disc and I have checked and re-checked it, bled it, adjusted it, etc. and it still does not work right. I had the car jacked up and in gear at idle and the back wheels would spin at like 5 MPH or so since there is no resistance on them and with the brake pedal slammed to the floor the wheels would barely even slow down. If I where you I would look to the after market, companies like Baer, SSBC, or Wilwood have kits for our cars. SSBC has a complete front 1LE kit for our cars, not sure about the rear. I Baer offers alot, I would check with them first. If you have any questions shoot me an email. I will try to find that post sometime.

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Poor college student(donations welcome ;0) with an all stock 1988 5.7L IROC-Z Hardtop, Auto. trans, white ext. w/gold accents (soon to be silver), black custom cloth interior, 4-wheel discs and G92 pkg. Car is dead stock. Has only standard Z28 power options and all the IROC performance stuff you could get. No pwr. seats, mirrors, or rear defrost.

Best run: 1/4 14.90 @ 92.7 MPH

See My Car here: http://zap.to/chevyguy1969

#3 Gone but shall never be forgotten. Long live the legacy of the man in black. RIP Dale Earnhardt "The Intimidator"

 

Good point, I look up the prices on calipers and rotors yesterday, it blew my mind. I had to rebuild my rear calipers twice already, they are really wussy when it comes to heat. The baer kits doesn't run cheap either though. Thanks for the advice though.

 

Here is the link, go down to the part of "replacing your rear calipers" and read the info.

http://www.isthq.com/~dan/1LEbrake.html#1LErear

Its actually the calipers that experience the failure, not the whole system. I need to read this article some more myself it looks like.

 

are all disc brakes better than jfront disc and back drum?

 

I swapped disc brakes on my drum brake axle and changed the proportioning valve. I noticed nothing in braking improvement and the are a PIA to change the pads (Nothing like the front) Drums are much easier + cheaper to work on, Since I am swapping to a different ratio with the torsen I just got a 92 rear with drums and i'm leaving them on there.

The only advantage to rear disc brakes is with open style wheels, they look better...

If you really want to go and improve OVER both systems, go with the rear drums and aluminum drums. At $45 a pop they're pricy, but light.

And for drag racing drum brakes are better because disc brakes always have some amount of drag whereas drums fully disengage.

Just some of my thoughts on the PIA, e-brake cable never workin', caliper seizin' lame GM disc brakes.

 

Serpentine didn't come on our cars until 88.

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89 RS

STILL Looking For:
An 87 IROC-Z28 350 TPI