Need help with rear diff LSD!!!
 

Alright I need help!!!!

First off I need advice on which is better and why, and if it's a good deal...

These are the two diffs available to me which I need help choosing the best one.

98 TT auto rear diff with LSD 3.77 gearing with 78,000 miles- 1000.00 shipped + paypal

97 NA 5 speed rear diff with LSD 4.08 gearing with 85,000 miles- 975 shipped + paypal

are these deals? which one should I go with? I am staying NA SC4
Thanks in advance

I know there's rear diff guru's out there!!!!

I have a limited knowledge about the diff, but I think the NA 5 speed diff might not fit in the SC. I don't recall hearing of the NA that has LSD, so it may be just the open diff. I'm quite sure the TT auto LSD fit, though.

The JDM Soarer diff had limited slip

Those diffs are hard enough to come by that people over charge for them.

If you are staying NA, I wouldn't bother with it.

Some supra NA's actually had option of oem lsd from toyota, not sure what years though. I'm running a complete diff and axles from a 97 Supra NA that had factory lsd and it all bolted right up on my SC.

OP: What is your current setup and goals?

cherplex: how do you like your setup right now, i'm na-t and pushing a little under 400 whp and similar torque, would i be satisfied with the supra tt auto pumkin and axles? I've been getting ready to buy one coming up, but everyone seems to upgrade from the stock torsen unit to a trd anyway, so would you recommend the setup you've got or skip it and go straight to trd?

Goal as of now and probably for a while is to gain more bottomend stock motor. I believe headers and BFI are concidered stock still. My only thing is would the NA LSD rear diff be to tall of gearing that I'm gonna hate it and wished I went with the TT diff instead.

With your power goals the stock setup should be fine. But boost is addictive and sooner or later you want more so long term TRD would probably be the best bet. I will probably end up going with a V160 setup and will get the TRD for diff when I do.

The NA LSD rear should be just fine because it doesn't sound like you plan on building a highway monster. I ran out of gearing just pass 16Xmph with my setup but I'm ok with that well for now ha ha. But just depends on your goals like I said.

go 4.08 NA if you aren't going turbo or get the 3.77 if you do plan on going turbo.

I have the NA LSD now and it will be pretty short once i swap to a GTE engine.

Not trying to build a 200 mph freeway monster I want to have low end hit power. Also that will probably throw off my speedo, how do I fix this?

exactly....

SOunds like thatll be the plan, Ill keep you guys updated. Whats the name of that company that has a chip or something that helps calibrate your speedo?

Is the yellow box any good?

Alrighty decided to go with the 98 Auto TT rear diff w/ LSD. Had the diff checked out and it was in perfect condition!

Installed it today! I had high expectations and thought that it was going to be a significant difference in performance (bottom end wise), not really. Is this what other people got out of doing a rear end swap too, or is it just that my expectation was too high?

What engine do you have? Is it boosted? The significance that you'll feel is when you corner hard or when your car is powerful at launch. Otherwise, you won't feel much difference. The LSD doesn't give you any bottom end power. It only gives you more traction control. If your car isn't powerful enough to lose traction, then it's not benefitial. If you want bottom end power to go down quicker, you'll need to have a high stall speed torque converter for the auto tranny.