Tii LSD vs. NA LSD
 

which is better and/or stronger? I have searched the FAQ's and the forum and found nothing covering specific model info on what came with what and nothing covering which is more perfered. Any info is appericiated, and thank you.

The TII has a stronger LSD, transmission, and halfshafts. This is why I always recommend simply selling an NA car and buying a TII rather than going through all the trouble and expense of swapping parts in an attempt to turn an NA into a TII. The TII and NA differentials have a different bolt pattern, so they are not interchangeable unless you use a custom driveshaft.

What transmission are you running? NA or TII ? What engine?

Yeah i would sell my NA and pickup a Tii but the prices for Tii's in my area have sky rocketed over the last year, seems everyone wants one. Well to be truthful, i would like to convert to a Tii and had intentions of doing so and i might even do so if i have enough money to play with. But, dont get mad when i say this, I am really starting to build up my inventory for a V8 swap, i have purchased a LT1 and and will start making payments on a T56. I was just really wanting to know if i should go with the Tii LSD unit or get by with the NA lsd unit? I think the Tii unit is the way to go, so i get bigger(diameter) axles. I have a 91 NA rx7 BTW. I thought about going with the Ford 8.8 rear diff, beings i have one just sittin and it's even TRAK-LOK. But was wondering if i can get by with a Tii LSD assembly? Also how is gear selection look for the Tii units? Can i change out for some custom gears?

I have seen many people run V8's with the TII LSD they hold up fine, either way your gonna need a custom drivshaft.

Put your flame suit on!

then get a 240sx piston power =p

just kiddin.. the v8 swap takes away from what makes the rx7 special..

but whatever chassis you get, should be ok.. if you get a NA chassis, you might end up with a open diff non-lsd.. then just put a LSD from a GXL or some higher end NA model... early S4 model 86-88 model has clutch type lsd, which you can rebuild, and you can basically rebuild it for more lock. I want to go this route myself.. I have a TII converted NA with TII tranny/driveshaft.. NA open diff rear end, but the diff was welded so its solid.

Mazdatrix sells rebuild parts
http://mazdatrix.com/G8LSD.HTM

Well i own a 1991 NA rx7 right now. But i guess i need a Tii diff and axles. So does anybody selling custom gear ratio kits for the 2nd gen diff.?

so does anybody know over here, they moved my post over into these section.

get T2 diff/axels for sure. the lt1 torque will shred the NA diff with any kind of traction. its cheap insurance. and considering how annoying it is to change a diff, you might as well do it while the car is already down.
as for gears, you're stuck with 4:10. there are no aftermarket gear sets to date. it will be fine tho with the t56. if you really wanna gear it out some, just run taller tires in back. 275/40/17 will put you at 2k rpm at 75mph in 6th.

eh na fc diff n shafts will hold up to 300 hp no prob. of course the turbo is going to be of greater strength but the spline count is miniaml if your gonna run a v8 u should definatly get a tii rear end but you should also take care of the rear end it can only take so much abuse. i wouldnt recomend slicks w/400+ wheel torque and a s4 turbo rear end but im sure it would last mabye one launch lol

^ turbo diffs are good to go. axles are the limiting factor, but thats with ~500lb.ft and sticky tires. dudes run 9's on full slicks with the stock TII diff. wheel hop will kill them faster, but thats true for any rear end part.
NA diff however will explode with 300 lb.ft. maybe not the first time you drive it, but soon enough. they jsut arent strong enough for that kinda torque, unless you're rolling all season 205's on the back

so should i serouisly consider a 8.8 swap while i am at it?

8.8 swap?

i have a na in my car right now (will be behind an auto transmission and a 360 mopar engine), as soon as i can i am swapping a solid rear, most likely the dodge 8 3/4

anybody have the 8.8 under their FC

razorback, your working on an FC now? awesome. do y ou have a link with any pics?

how much power do you plan on making? will you be using slicks?

I do. 04 Cobra.

yep, have been for a while. was going big block, but that is ALOT more work than i want to do right now, and a small block is alot easier to do. i just got my oil pan so i can finally start making motor mounts, no real pics of the current swap, but i have some from my old big block thread in this section from a few years ago.

as far as slicks, not now, i will have set after i get solid rear installed. power wise i hope to have similiar setup to this:

http://www.hughesengines.com/general...icleID=1000020

so around 400ish i hope.

so what more should i know on the subject of the diff to use. I am shooting around the upper 300rwhp to low 400rwhp. Will the Tii rear and axles handle that amount of power and torque and maybe some runs down the 1/4 mile at street night at the drag strip? BTW i will be going with a T56, so its possible the drivetrain could see more stress their vs. a 4l60E.

TII goodies are fine. you'll break your subframe before the axles/diff go.
use a pinnion snubber and avoid wheel hop, if you're on radials or slicks

what is a pinion snubber?

go to autozone.com, and search 31052. its a rubber bump stop thingy that will mount betweeen the diff and the chassis. it prevents the nose of the diff from moving up too far, which often results in broken diff mounts, or broken subframe.
i cant find an install thread with pics, so i'll try to describe it.

take out one of your bins (or the back seat), and right in between them you will see a 1/2 inch diameter indent in the sheet metal. it kinda looks like a guide hole. you drill it out (same diameter as the snubber's threads), then mount the snubber. you will most likely have to remove your diff, so do it when you're swapping it out.

the nose of the snubber will sit against the top of the diff, and you can relax with no more broken parts.

with 400hp you should be fine, id pay more attention to the torque, and a manual IS harder on a rearend than an auto. there were a few guys getting into the 9s with a stock t2 rearend. id go that route, but the gear ratios are not what i need with my current and planned setup.

http://www.amazon.com/Help-31052-Con.../dp/B000C5E428

so buy this motormite/help!/dorman parts and use a little ingenuity/know how and install it to keep the nose of my Tii rear end at the proper ride anlge at all times?! Is this going to help stop wheel hop? What can i do to eliminate wheel hop? Are there any subframe connectors made for the FC's chassis?