Matthew91-Z28

Alot of late model g-bodies run 12 in rotors by getting a spindle from a caddy, or caprice wagon, a caliper from the same vehicle, and a 1LE rotor. http://www.carcraft.com/techarticles/57098/index.html

The only reason why I'm interested in this is because I want to know if you can put 12in brakes on a 3rd gen for cheap and with no whammies.

I have looked into it. I got a caliper from a '84 caprice wagon. Looks like a stock 3rd gen caliper on steroids. Its huge! The piston is about 1.5 times as big as a stock 3rd gen.

Anyway, its a little tricky, but I think I have most of this puzzle solved. I have already designed the bracket, but have not machined one nor test fitted. I'm having my spindle machined as we speak.

Just a small disclaimer: I'm not saying that this is better than any other 12in setup already discussed on this board. I just think its alot less work intensive (no hub, no searching for bigger lugs) and cheaper. But then again, you get what you pay for.

The good things are that you can get the braking torque from a 12in rotor, you can have good braking by running a much bigger caliper (more surface area), and you can do it cheaper and with alot less hassle than other brake mods.

The bad things are that it will be heavier and you won't have the more responsive dual pistons (1LE, LS1, vette).


Oh...almost forgot. I need the caliper piston areas for the vette, ls1, c4, and 1le. Anyone got this info. I remember reading it in one of the brake upgrade posts, but can't seem to find it via searching. I need to know so I can compare.

ebmiller88

iTrader: (7)

Interesting read...I've heard of swaps like that before. I think it would be an improvement over the stocker. Please post some pics of what you have going so far.

As far as the dimentions you were asking for, I have no idea, but I think Alloy has the figures somewhere. He did a lot of number crunching in the C4, LS1 and C5 threads a while back, maybe he can help you out,

Good luck!'

Ed

Brett H. - 89GTA

How do the spindle mods look? Similar to the 1LE & C4 brake mods? Is the bracket design pretty straightforward?

I wonder if SSBC makes a Force 10 caliper that would fit so that you could still have an aluminum dual piston caliper. Of course, the low buck nature of the idea would go out the window.

Matthew91-Z28

Well, I won't be able to show pics of the spindle mod until I get it back from the machine shop next week. But here is a short description. You know how on the stock spindle, one of the spindle "ears" is forked?? Well, for the first cut I shaved off the outer fork down to the plane of the caliper bolt boss. I did this so I can get the 12in rotor on the spindle for test fitting and bracket design.

Now whats left will be the two stock ears. There are 3.5 inches of space between the two ears where the stock caliper slides in. You'll need around 5.5in" to fit the '85 caprice wagon caliper (2.5in" dia and 4.9in"" piston area). So the next cut will be a line across the bottom of the stock caliper bolt holes. This cut will shave enough of the stock ears to fit the new bigger caliper.


I wanted to preserve as much of the stock ear as possible to act as a scaffold and support for the new caliper bracket. So you'll only need to take them down about 1 inch (like I said to the bottom of the bolt holes).

The new caliper bolt holes (compared to the stock) will be about .75" (per side) to the outside and about .75" higher.

Here is a basic plan of what the bracket will eventually look like. Keep in mind that there are 3/4" (12/16") space between the rotor and the ears, so its easy to run a 3/8" thick bracket. (Only one side showing the new bracket).

Matthew91-Z28

Oh...and the Force10's use the existing bracket. They were supposed to have them for 82-92 f-bodies last June. Damn they are pricey though ($380).

Just another side note. The bracket design above is only tentative. I have other designs in mind. SO...its not final or anything. I still need to get my spindle back so I can really get to work on it.

Brett H. - 89GTA

I figured the Force 10 calipers for the F-body wouldn't fit with the 12" rotors. They do make them for some G-Body cars, but I don't know if they are the ones with the big rotors. I agree, they aren't cheap...

Matthew91-Z28

No they won't fit a 12 in rotor, at least without a modified bracket. I'd like to find some cheaper 2-piston calipers like that that don't require a basket (unlike the 1LE pbr's). But, I'm confident that the '84 caprice wagon caliper with its huge piston will deliver some puckering brake power on that 12in rotor.

SLP-GTA

iTrader: (1)

market the bracket and spindle mod, could make you some $$$
to buy other performace mods for the Z28 Matt

Matthew91-Z28

Wow. Thanks for the encouragement. I really hope this thing works out. Depending on how well they work, I might put a few sets together for people who are interested in purchasing them. But (don't worry) I won't withold any info on how they are built from the board members.

I really doubt any company selling big brakes would market them because they are just TOO cost effective and would take money away from their $$$ products.

Oh well. We'll see soon enough. Nice ride by the way. She's pretty.

ebmiller88

iTrader: (7)

I thought about the Force 10 calipers a while back but there's 2 problems with them; #1--Price. Too much money just for a set of calipers; #2--They use a stock rotor. What's the use of upgrading if you can't increase the rotor size?

Let us know how this turns out for you Matt, looking good..

Ed