I don't think my original stock torsen diff will withstand many more passes down the strip, especially given my FD's added power over the last few years (I havent drag raced in about 4 yrs). I have a brand new TII diff sitting on the shelf and am comtemplating having it installed.

For those running one, how do you like it? Any other 'makes sense' stuff do have done while in there? ie diff bushings. My FD has 112k miles on the chassis.

thanks!

 

I've been running the S4 diff for over a year now. I blew up my Torsen in the end of 2004, and got lucky and didn't split the case. So if you got the power and the time I'd change it NOW. The case is getting pretty hard to find. As for the diff itself: The very first pass I made with it was my fastest to date. And it has held up for all last summer...Now if I could get a clutch that could.
I also changed to solid diff mounts while I did the swap. Your already in there and they are only $50 so might as well. I did notice a differece between the diff mounts and the KG brace my rear end doesn't hop one bit. Good Luck

 

thanks for the info. Did you need any addtl mazda parts, ie diff shims etc?

 

i am just taking mine to a diff. shop/offroad store. thet set-up alot of diffs, so i dont have to worry about it

 

rich,

solid diff bushings are one of the two essential bushing changes, the other being the bushings at the front of the lower longitudinal link. replacing both w either nylon or higher durometer bushings will aid toe consistancy and axle bounce under launch. no other suspension bushings need to be upgraded.

if there is any doubt, slip a floor jack under the diff and start cranking. you will find the diff rises over an inch before the chassis starts to rise! can you say axle hop?

as to the S4 T2 LSD... i have a freind who has an LS1 FC and he has been HAMMERING the rear end without mercy and has had NO diff problems in 2 years. i cannot believe how much punishment it takes. i have a T2 LSD on the shelf and will shortly be ditching my Torsen. i do not want to split my case.

regards,

howard coleman

 

Great info, thanks Howard

 

Looking for more input.

Howard, do you plan on road racing with the clutch type diff vs the torsen? I hear about drawbacks on the road course when making the switch, but have never been presented with any firsthand accounts.

 

I'm bringing this back form the dead, anymore input on your TII Diff. I am curious of road course issues as well.

 

I have one in my twint04 fd. It is used mostly for drag racing and has seen a ton of launches on slicks with zero problems. Tough little unit.

If you have a street car, I would get this over a Kaaz, etc.

 

I ended up having my brand new S4 TII diff cryotreated, then installed along with a 4.3 final drive from www.rx7.com. I also bought all the needed oem parts from ray at malloy, including a pair of side oil seals, a pair of bearings, and a crush sleeve. That last part is only needed if you're going with a different final drive. I re-used my stock casing and stock axles. I was tempted to go the 300M chromoly route, but it wasn't in the budget unfortunately.

Everything works very well on the street. I've made numerous hard redline shifts with the 400R setup at anywhere from 15 to 19 psi with no problems. I did drag race it at last year's rotorfest, made about six passes and the diff held up fine. It was hot as hell that day and the boost was turned down.

 

^Theres a 400r?

On another note... i remember hearing once that a diff support causes more pinion pressure backward and up. In the long run it will lead to the case cracking. Is my memory wrong?

 

bah! It's a 400R until I get dyno results out of it

Re: your memory, while at Gotham I sold and saw installed many many diff braces and never heard any reports of cracked cases.