Hi everyone I am coming here to get a little advice or should I say motivation to buy a 89' GTUs rear end. I am in the bay area and found one out here for sale for a decent price but am concerned if it's actually worth getting the viscous lsd compared to getting a torsen, or maybe clutch type. I've heard the good and bads of all three but is a viscous lsd that bad? I've never had one in any of the cars I owned so I don't know how well it handles. If anyone could help that'd be great thanks.

 

Im not too familiar with the viscous diffs in an rx-7, but my brother has a VLSD in his 240sx. He feels that its better than an open diff, but falls short of clutch lsd. The way it responds is different. Wheelspin(wheel speed difference) must occour before the fluid tries to "lock" so it has a bit of a delay. Its better than an open diff, but not near the performance of a clutch lsd. I have no experience with a helical lsd though.

 

Viscious - a lot better than stinking open diff. so so for racing and drifting
Clutch - best of all there is, good for racing and drifting
Torsen - best for daily driving and least maintenance (from what i've heard), not sure on how it locks. but it's suppose to be the best on snow and rain without having it slide out unexpectedly.

 

How would one know if they have any of those lsd's? For some reason im thinking my FC has a torsen but am unsure how to identify it. Any ideas?

 

The only FC that came with a Torsen was the Infini IV, but I suppose its possible some swapped in a Torsen from a FD.

The only way I know of to check to see if you have one is too look inside at the gearset inside the diff.

In therory if you jacked the car up and left one wheel just touching the ground, if you turn the drive shaft, the wheel just touching the ground should be the one wanting to spin.

But mind you I have not done that so I can not confirm if it works or not as a test for a torsen.

 

I thought that it was the TII that could use the Torsen from a FD while on an NA the easiest way was the rear end off a Miata.

 

Yes that is true

 

So...just for some beginning practice drifting a viscous lsd should be able do the job just fine. When I hopefully get better I'll look into to getting something more serious but for now it should do the trick, right? Also thanks for all the good replies they always help.

 

Clutch type would be better, if you're staying with oem parts, but they do need occasional rebuilds for heavy drifting.

 

This may be some what of a stupid question but it does go with this theard. What rear end lsd came in a 1988 vert rx? I've read the sticky at the top of the form and I'm confused. I have an 89 GTUs rear end I could swap in if thats better. Thanks

 

The 88' verts have open diffs. I had one myself and I'm pretty sure it's a crappy open diff.

 

I have experienced all three types (open, vLSD, cLSD) on NA FCs.

My GXL has clutch type, and it locks quickly, but it requires some initial torque to lock up so it wont help in the ultra slick (snow/ice).

My 'Vert has a vLSD installed, and it takes some spin before it locks up, but it is more eager to lock (In my experience) and is more useful in regular street driving, and unlike the clutch type, it won't wear out and need a rebiuld.

The open diff is worthless :P

If you are really desperate, you can always just weld the spider gears in your open diff and have a totally locked diff. Great for drag. Terrable for street/drift/anything else :p

All US 'verts are N/A with an open diff.
The S4 'verts got another kick in the teeth with 3.9:1 ratio gears.

 

VLSDs suck!! Get a Kaaz, Cusco, or something like that!! Trust me you will be happy. LSDs are an upgrade that you will never see, so some people dont put it on the top of their lists. The only problem is the MONEY!!

 

So should I swap the diffs so I could have the vicous I'm pretty sure the 89 GTUs has that. And how hard would it be to swap? Thanks

 

Man this sucks. I've been driving with an open diff for 2 NE winters

 

Oh man if I could afford a Kaaz or Cusco LSD I'd definitely get it but like you said they are $$$$.
To Matt88 yes the 89 GTUs has a viscous lsd that is the same kind I'm thinking of buying right now. Thats why I started this thread because I wanted to hear what others with VLSD experience have to say about it before I buy it. But I am not sure how hard it is to install I'm jus gonna get the shop manual and go to work. I've heard it isnt too hard cause it is pretty much just a straight bolt out and bolt in.

 

I've got a 90 GXL and I swear its got the viscous lsd... is that right or am i feelin ****.... I get a spin before they lock...... then Its all good I'm pretty use to it... do miss my TII thou...

 

Once you figure out how to swap them out can you let me know? Thanks

 

this is a wonder to me, Cause i have an 88gxl with the LSD rearend, and it has a mind of its own, in the rain both tires will want to spin not just one, in the snow or ice on low speeds then one tire wants to spin,

 

Yeh, you can either swap the whole unit at once, or just swap the carrier. It's not that hard.

 

this might be a lil off topic but... i own a 1991 GTU coupe, any idea's on what kind of differential i have? what kind of differential would you all sugest for street racing- but mainly for handling corners? also i would like to get a bigger rear end gear for more torque, got any ideas on where would be the best/cheepest place to get one? (i want as much torque as i can get and still go around a 140mph)
sorry for all of these stupid questions, i know a lot about rotarys but nothing about differential

 

Covered in the FAQ for FC sticky thread at the top of this section...

First... no such thing as a 91 GTU coupe in the USA. Only coupes with option packages (covered in the options and Standard features sticky thread at the top of this section).

2nd the 91 coupe came only with an open differential.

 

i own 13 rx7's, three of wich are parts cars. do the 1988, 87, or 86 coupe gxl's have any better rearend parts worth changing?

 

Manual tranny 86-88 GXLs will have a clutch type LSD with a 4.1 rear end gear.

 

anyone know what kind of LSD is in the 86-88 GXL model?