LS1 rear discs on a GN

[Bruce]

I just recieved my set-up for doing this, and just stumbled on to this.

http://www.thirdgen.org/newdesign/tech/ls1reardisc.shtml

It'll be a while before I get mine done, thought this might be of interest to others thou.

[instro84]

thanks for the info Bruce, did you do the LS1's in the front yet?
Dale

[1badTTA]

I am wondering if they can be easily installed on a TTA rearend. I need to find a solution to the TTA rear brake calipers flexing and bending while trying to hold boost. The drum style E-brake is an added bonus too.

[Bruce]

thanks for the info Bruce, did you do the LS1's in the front yet?
Dale

Yep.

Incredible stopping power. I makes even the B Spindles, 12"ers look feeble.

[Bruce]

I am wondering if they can be easily installed on a TTA rearend. I need to find a solution to the TTA rear brake calipers flexing and bending while trying to hold boost. The drum style E-brake is an added bonus too.

Did you look at the link, to see if the axle flanges are the same as your's?.

It's been years since I looked at a TTA rear axle.

[1badTTA]

Did you look at the link, to see if the axle flanges are the same as your's?.

It's been years since I looked at a TTA rear axle.
That's why I was asking, I haven't had mine down to the mounting flange to see if it would work, I was hoping someone had though. I may just have to take it apart just see if it is a straight up swap though.

[Dave Jones]

I need to find a solution to the TTA rear brake calipers flexing and bending while trying to hold boost.

If you're certain that caliper flex is the problem, I'd be looking for a different caliper. Visually, the '98+ rears didn't appear to me to have significantly more material in the bridge than the older PBRs do. (I've heard that the ZO6 calipers are a bit stiffer, but I don't know if that applies to the rears as well as the fronts).

FWIW, the only time I've known for sure that caliper flex was an issue with PBRs was when they were really hot. It doesn't take that much heat before the aluminum loses it's stiffness. I'd suspect your problems holding the rears at the line have more to do with caliper piston area. I believe that GM wanted to make it difficult to lock the rears for liability reasons, and that translates into piston ratios that aren't exactly ideal for holding boost at the line.

On the positive side, at least you don't need a line lock to do your burnout. :-)

[shmed]

that sounds good, does anyone know the diameter on the backing plate?
the hole that slides onto the axle?
im running the ford type bearings and there quite large 3" i believe

[Bruce]

that sounds good, does anyone know the diameter on the backing plate?
the hole that slides onto the axle?
im running the ford type bearings and there quite large 3" i believe

I got 2.83".
Looks like there is some meat that could be trimmed out. I'll leave the final descision to you.

[TRFanatic]

So these rear discs are a straight swap for a GN also? Bruce, how much was involved in the LS1 front discs. I agree that added braking is mandatory with these cars.

Thanks so much for your info.

Ravi

[Bruce]

So these rear discs are a straight swap for a GN also? Bruce, how much was involved in the LS1 front discs. I agree that added braking is mandatory with these cars.
Thanks so much for your info.


Going by part no.s, the backing plates, drums, shoes, etc., are the same between the two cars.

I still haven't done mine, but hopefully with the warmer weather, coming up, I'll be able to *Get R Done*.

I bought the fronts as an assembled set-up from Ralph, on TB.com. He has another set-up (or did) for $700, that comes with the spindles assembled, and is a complete bolt on.

There's a thread about the fronts.

[Bruce]

Well, got the rears on today.

Good news is that they work great.
Bad news, is that they only seem to fit with a car that's been min-tubed.

I still haven't figured out how to get the emergency brake cable mounted, but it looks manageable.

While I'm using a 84 Regal Master Cylinder with a vacuum booster, shortly I'm going to try a 92 Trofeo. It's a late model design, fitting on the correct side, and 1" bores. Oh, and it has a low fluid level sensor in it.

HTH

If you wanted to forget the emergency brake, you might be able to mount the Calipers on the rear of the axle, and if the car wasn't lowered, you MIGHT get by.


*******
03/30/05 Update

Photos attached. The link to TGO, explains what needs to be done.

Again, it's close with mini-tubs, and a stock height car **might** be OK.
Flipping the calipers to the rear, and not using the emergency brake might work for a stock height, stock framed car.

For brake lines, I used some 3/16th Bundy, then (2) 12" -3 AN Brake lines, (2) -3AN to Banjo fittings, and (2) inverted flair to -3 AN fittings.

It probably was somewhat easier since I had the PSTs on than the Drums, and it was a FULL days project.

[instro84]

Bruce, can you post some pics?
Dale