torsen and autox

[blackmamba92]

been looking for a torsen rear end. Wanted to know what benefits i would get out of this for autox and is it worth the cash? How can one check if it is a torsen when its out the car?

[Dynra Rockets]

been looking for a torsen rear end. Wanted to know what benefits i would get out of this for autox and is it worth the cash? How can one check if it is a torsen when its out the car?


For autocross a torsen is very worthwhile.

See solomiata.com for process and pics. Pull the stub shafts and look in the center for a hole or a spyder gear bar. You can also just pull the fill plug and look for a torsen if you know what it looks like.

[blackmamba92]

unfortunatly i have no idea what im lookin for. A ride along would be best or some pics of one.

[blackmamba92]

http://atlanta.craigslist.org/eat/pts/1829410999.html

here is what im lookin at.

[nickt93]

If it is from a 1992, then it is not a Torsen. The 1.6 cars came with a viscous LSD. The viscous LSDs wear over time, so this one may or may not have much "limited slip" left in it.

Here's a good article for understanding Miata diffs:

http://www.miata.net/garage/vlsd.html

[Dynra Rockets]

http://atlanta.craigslist.org/eat/pts/1829410999.html

here is what im lookin at.


If it is a 92 diff then it is not a Torsen.

Both wheels spinning does not nessessarily mean it is a LSD. a balanced light weight car with IRS will spin both wheels even with an open diff.

See solomiata.com for pics (or just google, there are thousands of Torsen pics on the web)



I had a one family owned 1992 Miata that was NEVER wrecked, raced, modified and well maintained until an accident last year so I parted the car out.

Should fit 1990-1997 Miatas as most of these parts do, but to be sure I can find out for you.

Both wheels spun so it is a possitraction rear diff

[blackmamba92]

am i better off just rebuilding mine? For cost and ease?

[Dynra Rockets]

am i better off just rebuilding mine? For cost and ease?


A torsen does not materially wear and is not end user rebuildable. The only thing rebuildable is the diff pumpkin itself for bearings and seals.

[blackmamba92]

i mean my probably tired old viscous.

[Dynra Rockets]

i mean my probably tired old viscous.


also not rebuilable other that bearings and seals.

The best you could do with a 6" rear is it install one of those Mazdaspeed, Kaaz or OBX clutch type LSD's in that housing.

[blackmamba92]

mazda speed one would work with the update backdate rule would it not?

[Dynra Rockets]

mazda speed one would work with the update backdate rule would it not?


no. Mazdaspeed as in the old aftermarket parts manufacturer and not the turbo model.

I'm not up on my CSP rules but IFAIR you can use an aftermarket LSD.

[blackmamba92]

any one in particular that is prefered? How can i tell if mine is worn?

[Dynra Rockets]

any one in particular that is prefered? How can i tell if mine is worn?


Read FAQ posted above

The VLSD new only has 11 ft lbs torque. If it is les than 11 ft lbs it is worn. Even at 11 ft lbs you will get inside wheel spin with sticky tires on an autocross course.

Clutch types are typically in the range of 25-50 ft lbs loack-up. Some can be made to 75 with a ramp change, which is pretty much full lock.

For a clutch type you have to decide which action style you like best. 1 way, 1.5 way, or 2 way and how much lockup you want.

I prefer the action of a Torsen of being open for 2/3 way through the corner and then full lock for the power on last 1/3