I recently installed a zexel posi in a 3.42 rear that I picked up for my 87. The zexel seems to work pretty well except when I completely unload the inside tire and hit the throttle hard. I ran two autocross events this weekend and when I was in a hard corner and the inside rear tire was unloaded, I could easily spin the inside tire. I suspect it's due to the design of the zexel and it not having enough torque on the inside tire to lock the unit up in hard turns. I've found without some torque applied to the zexel, like when the car is off the ground you can spin one tire, and the other tire rotates the other direction. I think this is exactly what is happening.

I'm running Yok. A008 tires and although no one told me, I suspect I'm lifting my inside rear tire on hard cornering. My car has 24mm rear, and 36mm front bars and a 3 pt. STB, along with Koni red shocks all around.

Before I go to the expense of pulling the Zexel out and going to an Eaton with clutches, I'd like to know if anyone else is having this kind of problem with a Zexel?

 

Is it a "take off" from a 4th gen or a T2R?

Before going through all that ha$$le, I would try going with a smaller sway bar in the rear. I was having trouble putting power down with my "take out" Zexel-Torsen from SLP with a 21mm rear sway bar. Coming out of turns, the gas pedal was almost useless until the car got straightened out. But I went back down to a 19 mm bar, and the car hooks up better. It understeers more, but it's now easier to correct (and more stable) by giving it more throttle.

It's still not quite to my liking, though (I don't run on Kumhos or Hoosiers or any other R-compounds so my car is already at a disadvantage for grip). There still seems to be a fine line where the OEM Torsen works OK ... either you barely don't give it enough gas and the car understeers or you give it just barely too much and the back end dances around.

 

The Zexel is a take out fom SLP.

At this point in time I'm very hesitant to swap in a smaller rear bar. The car is neutral now with this combination in the dry. The wet is another story. The back end feels like it's on ball bearings in the wet.

In all but the hardest sharper turns the zexel works very well. It's just the higher speed ones where I'm approaching max tire adhesion that I'm having a problem. I've worked up in sway bar size in small increments to the 24-36 combo with ureathane bushings and with each change the car got more stable, so I'd really hate to go backwards with the handling I've worked on so hard.

I've found Eaton posi's for $300, which is a lot less than the $469 in Summit's catalog. I can also sell my Zexel which will offset the cost of the Eaton somewhat.

Anyway, I'm glad to hear that I'm not the only one having this kind of difficulty with a Zexel. I had a feeling that it was the lack of torque to the inside wheel that keeps it from locking up like I want it.

 

I have also noticed this a few times last year, bot only on off camber turns. It's still better than the open diff that my car came with. I would like to try the Torsen T2-R.

As for sway bars I'm still running the stock 34mm/21mm units, but I plan to experiment with a 24mm in the rear to see if I can get the car to rotate faster.

 

Oh yeah, I forgot how cheap you can find the Eatons. The only drawback is that they wear out, but at least they are rebuildable unlike the Auburns.

Although the Quaife in my Sentra SE-R cost about $900, so even a T2R is cheap by comparison.

From what I've read in other places (and going by a couple people who have driven F Bodies with T2R's), the T2R is preloaded with springs so the unloaded wheel doesn't spin as much (or at all?).

My T2R is going in tomorrow so I'll know more soon!

 

Axoid,

I completely agree that my Zexel is better than the auburn that was in the car before. But I need a little more from a posi. I find myself lighting up one of the rear tires often and have to back peddle and let the car settle out before giving it throttle again. I can easily see at least one second per run that this is costing me.

I think you will like the 24mm rear bar, but the rear of your car will be on ball bearings in the rear when it's wet. You can EASILY throw the rear out at will with the 34-24 bar combo in the dry, but as I said it's murder in the wet that way.

I had 34-24 bars on, then went to a 36 front bar just recently. Adding the 36 bar did help in both the dry and wet, but my rear is still very loose in the wet. I don't think there is any way to get around this on a 3rd gen.


Slow305,

I'm very interested in hearing your opinion on how the T2R works. I don't know much about it, and don't know anyone running one either. So please get back to us on how it works as soon as possible!