just to let everyone know, i just finished mounting my 9 bolt brakes (11 inch aluminum pbr) to a 4th gen 10 bolt. all i gotta do is just drop the 9 bolt and swap in the 10 bolt. i lengthened the brake lines just a tad so they would reach, but it was very simple. plus i kept my stock e-brake. so if you can get a 4th gen rear without brakes you can modify your brakes to bolt up perfectly to the rear. ill have pictures up later, its dark now so i gotta wait till light to take em.

i cant wait, today 2.77s...
tommorow 3.42s...

 

do you know if the thirdgen 11"rotors(PBR) on the 9 Bolt are the same as the fourth gen rotors? thanks

 

the 3rd gen rotors slip over the studs on the factory 4th gen hub perfectly so im guessing they are.

 

The calipers are almost identical (with the exception of some little piece in the e-brake assembly) for '89-'97. The rotors should be identical on '89-'97 cars without traction control. With traction control, I'm not sure, since I don't know where they put the ABS sensor. It's probably in the end of the axle near the wheel bearing, which would mean those rotors would be fine also.

 

the brakes are not a bolt on though, modification is required.

 

Didn't say there was no modification required; just that the calipers themselves are identical. I believe the 4thgen ebrake assembly hits the spring mounts since our axles are narrower, but I'm not sure.

I consider having to completely redo the hardlines as part of a normal rear swap any more.

 

What would it take to convert a an 87 disk brake 9 bolt to the 89 plus style of brakes?

Thanks

Ben

 

You'd need the entire brake assembly. You could get that off of a 10-bolt or a 9-bolt. Then you'd have to beg, borrow, or steal a set of 9-bolt PBR-style backing plates--that is hard because they've been discontinued for some time.

But you shouldn't have to do anything to the axle itself, aside from run new hard and soft lines.

 

What is different about this backing plate? Could mine be modified to work. Is getting ahold of one of these the only way? Sounds like it might be kind of difficult.

Thanks

Ben

 

They're really different. I've got a photo I took last night of mine, maybe I can remember to put it on my server so you could see it.

 

That would be great. When do you think you might be able to do that?

 

If I remember, I'll have 'em up tonight.

They'll be at http://www.camaro.dnsalias.com:8008/91Z/

 

cool, thanks

 

oh, and what does PBR stand for? And are the newer style rotors different or does this just fix the caliper problem.

 

No clue. PBR is the name of the company that manufactures the aluminum calipers. IIRC they made the 1LE fronts as well.

 

So, the last year of the 9 bolt was 90 right? Does this mean that I have to get this piece off of a 89-90 car with a 9 bolt?

 

oh no, thats not what i meant. i was just mearly telling everyone else that it was not a direct bolt on. i got away with only redoing the passenger side hardline. the rest even the third gen ebrakes worked perfectly.

 

oh and if anyone is planning to do this to a stock or near stock L98 (go with 3.42s), DO IT! it feels like a totally different car compared to 2.77s. i could used to barely get a 1-2 scratch on the shift, now its a 1-2 squeel. and the 1st to 2nd ratio drop isnt near as bad.

 

Ummmm.... Sofa King? Did you get a 4th gen axle without brakes? Because all of the LT1 Z28/Formula/Trans Am 4th gen axles will have those PBR 11" brakes on them (LS1 cars have even bigger brakes that I have heard will also work with some minor mods) and will work with minor mods on a thirdgen (need a new driver side hard line and a little tweaking of the parking brake cable bracket to accept the 4th gen parking brake cables that also will be needed). So if you are looking for a 4th gen axle you can get one with brakes and go from there.... Just thought I would throw that out there as it might save some screwin around for others..... But nice work! .

BTW, what does that name stand for, I know I have seen others ask, but I don't remember seeing your response..... I got a feeling there is a high quality story behind it .

 

his name says: you are so ****ing retarted (u r sofa king we tah did)

 

Momar,

I hope you got the pics last night. I tried posting a response here but the board was having a hissy and wouldn't cooperate.

 

matt87gta:

hell yeah this thing came without brakes! i wouldnt have done all this crap if it had em. the guy i bought the rear from replaced his with a ford 9 inch and reused his old brakes so i had to either buy new 4th gen brakes or see if the nine bolt brakes would work. i just figured i could make em work, and i did. about the name, lol, one night in my prime i was out partying very hard with some friends and this went on till about 2:30 in the morning, until tequila showed up after we were already drunk. long story short, we drank way too much that night and we went to a bar, well 3 of us were getting sick and the stall i went into had "U R SOFA KING WE TAH DID" written on the wall. all i kept thinking was "yep, i know"...

 

Hey u r sofa king we tah did, did you reuse your stock wheels? If so could you put up a pic of the car with them on? I would like to see how far 3rd gen wheels stick out with a fourth get rear. I’ve been looking at using a fourth get rear, but will not have the money for new wheels rite off.

 

I did get the pictures. Oh, u r sofa king we tah did, what backing plate did you use. Did you get a new one or did you modify the 9 bolt ones? If you modified them do you think that it would be possible to modify 10 bolt backing plates to fit a 9 bolt or if you used 10 bolt backing plates do you still have your 9 bolt ones because I would like to buy them if you do.

Thanks

Ben

 

yes i used the stock wheels. give me time to change my rear pads and a couple of bad wheel studs and the pictures will be up. the difference in width is pretty noticable, but i can live with it until i get some zr1 wheels.

 

 

I dont think it looks that bad. Now you can put some wide rear tires on though. Have you noticed a difference in the handling with the wheels like that?

Ben

 

the picture hides alot. its alot more noticable in person, when seeing the rear wheels in proportion to the front wheels. as far as the handling, ive noticed nothing really, except it bites harder punching it through corners, this is due to a better working posi though i think.