my 91 RS has a 10bolt rear and it is a LSD i believe (only a one-wheel-peel). would anyone happen to know if it's a 28 spline of 30 or what? i think it's got 3.08 gears and i wanna put posi in it with probably like a 3.73 gear. but there are so many variations that i don't know which way to go.

 

What you have is probably actually an open rear. LSD stands for limited slip differential which is GM's name for posi. You will have 28 spline axles. I think the changeover year was 89 from 26 to 28. My brother has a 91 RS with an open 3.08 with drums. I guess you can buy a locker but I forget the company that fits inside your open rear for pretty cheap. Also if you want a normal clutch style posi slp sells take offs from the forth gens for $99 but I dont know how long they will have them since the fourthgens were discontinued. If you change gear ratios to anything numberically higher you will have to get a different carrier or gears that are made for a series 2 carrier.

Ben

 

http://www.slponline.com/view_produc...TNUMBER=64501T

 

It's called a PowerTrax Locking Diff.

I have one, and I like it. I got the "quiet" one for ~$400. It is quiet, but the rear end is not. The little bit of play you have on the axles with drum brakes is VERY exagerated with the locker in there. Clunks are something you must grow to like. I doubt the disc brakes would have a problem since the axles are also ''held in'' by the calipers.

If I were to do it again, I wouldn't bother paying the $100 more for the "quiet" one. It wasn't worth it IMO.

You have to be careful. Whenever there's power applied to the rear end, you basically have a spool. Only while you're coasting does the differential work. It also works while you're going straight. If you let off the gas and coast, then goose it, you can feel the rear end lock up. It's something to get used to also because when it does, the rear end feels loose.

If you're coasting around a long curve, then start to accelerate, the car wants to go straight, or it feels like it does. Having power at both wheels while having the steering wheel turned causes the car to want to go straight more than inertia itself. Another thing to get used to.

And last but not least...... My car is sitting in the ditch right now. My wife was coming home from work and it started snowing quite a bit. (First snow of the winter) It was slick as heck, and since it's a non-forgiving locker, the *** end skated out from under her and now my car is *** first in the ditch on Interstate 57 south. I.E. if you drive in the snow, get ready for anything.

Sorry for the long post, but if I knew then what I know now, I probably would not have bought it. It's made for 20/80 street/strip time car. IT IS NOT MADE FOR AN EVERYDAY DRIVER!!!

 

AJ 92RS-
Sorry to hear about your wife crashing your ride- hopefully she is OK. Cars can always be fixed- but hopefully it didn't get too much damage.

I have the same Powertrax unit on my 91 RS. The clunking is a little annoying, but, for me, it is a good middle ground between full lock and an open dif.

I recently upgraded to Baer disc (had drum rear) all the way around and still get the noise (I was hoping, as you mention in your post, that rear disc would reduce or eliminate the clunk).

Also like the color of your car- is that a stock color? If no, can you tell me who made it? It looks very similar to mine (Glasurit red pearl).

Take care-

Now that I think about it, it seems that, even if the axles are held in place by the rotors/calipers, the splined coupler on the Powertrax unit can easily slide on the axle spline shaft, so I shouldn't be too dissapointed that the noise is the same as original, I guess.

 

She's ok, and so's my wife. She just perched it up on the side of the ditch. It didn't make it to the bottom, so no body damage. *whew*.

The color is the stock Purple Haze Metallic. It looks great in the pic, but that's because I took a pic of the only good side. The hood and deck lid are molting. One day (when I win the Lotto) I'll get it repainted and I'm certainly gonna stick with that color.

BTW, '92 was the only year of that color on a 3rd gen.

 

I have a powertrax lockright in my car. its awesome.

and for everyones info, its not nearly as quirky as everyone claims it is. its not tough to drive, but its not quiet. you might get a little jolt from it once in awhile, but it doesnt spin you around or anything you can just feel it locking up and unlocking. the only time its annoying is at very slow speed turning with the wheels locked out.....it tends to buck a little bit....but thats the only time it did that.

other than that, its damn near invincible......

i snapped an axle launching my car at 6000rpm on slicks, i pulled the carrier out and the splined end was snapped off inside the locker....i hammered the piece out and cleaned everything up.....there was absoultely NO damage to the locker whatsoever, not even a scratch. i was impressed. i highly recommend it

 

whats your 1/4 mile time 383backinblack