Torsen questions
 

Yesterday's autocross was, if I can do anything about it, the last time I'm going to deal with absurd inside-rear wheelspin on every corner exit.

I am staying in the low 200's range for power, so although I know some have trouble with Torsens in higher hp (300+) applications, I have chosen to go Torsen for my uses.

My main question is on the difference between the T1 and T2 Torsens - if I have my info right, the T1 was found in 94-95 and the T2 was the one in 96+'s, yes?

The search function is turning up little to nothing. So, which is considered better, and if the answer is not that simple, what are the advantages/disadvantages to either? If type of use matters: no drifting, lots of autocross, occasional track use.

I've got a guy who may be into swapping my 1.8 open diff + cash for his '94 Torsen diff, so I'm trying to get an idea of whether I should go that route or hold off for a T2?

Thanks guys
-Ryan

Good Discussion
http://forum.miata.net/vb/showthread.php?p=4644920

The one post in that thread that pertains to my question is Lance Schall saying that he's only heard of a couple T1's breaking and hasn't heard of a T2... but that's rather objective - I've heard of T2's breaking too...

I read somewhere else that some prefer the T1 for its characteristics over the T2 - something about the T2 feeling like it allows single wheel spin easier?

Looking for an and all input from you guys...

You may know this already but thought i would post what I know anyway. I dont really have any input on differences between T1 and T2, but stay away from a 03 (AKA the T-F diff) the cone clutch within the unit tends to shatter. Pretty much all the documented cases of failures are below 50k miles. The failure I had is the only one I found that failed with about 85k on it. It was fine when I put it in my car but as soon as I hit a little bit of boost the clutch shatterd. Fortunatly the R&P were unharmed. If i drove on it any longer there would have been more damage. The T-F has a 3.9 ratio.

If you end up getting ahold of a MSM unit, make sure you get MSM axles because they are slightly larger than ordinalry OEM axles. The MSM diff is a 4.10 ratio unit.

I believe the T1 transmission had slightly higher bias ratio due to the design - this will further help prevent inside wheelspin, though I'm not sure by how much. It might be negligible.

I think the T1 bias ratio was just over 2.5:1
I think the T2 bias ratio was just under 2.5:1

I want a T2R.

And what exactly is a T2R? Is that something found in any miatas?

No, unfortunately.

T2R is a Type 2 torsen differential with a clutch pack which was designed specifically to combat the shortfalls of T1 and T2 differentials when one wheel is completely unloaded. It pre-loads the tractionless tire via. the clutch pack IOT continue to direct torque to the wheel with traction even when one wheel is in the air.

IIRC, the S2Ks had T2Rs