Miata - swap to open diff?

We've been thinking of swapping my wifes torsen diff to an open one so she can run in scca auto-x stock class instead of street prepared.

What parts would I need besides the diff/carrier, and how cheaply can they be had for? Car is a beater/track type car, so I'd rather not have to sink alot into it, and don't plan to sell the current diff so I can sell it with the car later.

Thanks for any help.

Where are you located? I have a brand new, never used open diff w/o ring gear. I needed the gear and stub axles for the Mazdacomp diff.

SW-MI (St. Joe area).

How would I use what you have for what I need to do? Would I need to buy a ring gear and axles?

db wrote: SW-MI (St. Joe area). How would I use what you have for what I need to do? Would I need to buy a ring gear and axles?

You'd just use what's in the car already.

You mean street touring right? As long as the torsen is original equipment on that vehicle It is stock legal

yeah, sounds like it should be stock legal.

wait...Miatas had Viscous didn't they?

maroon92 wrote: yeah, sounds like it should be stock legal. wait...Miatas had Viscous didn't they?

90-93 did. 94+ had torsen.

Joey

db wrote: What parts would I need besides the diff/carrier, and how cheaply can they be had for? Car is a beater/track type car, so I'd rather not have to sink alot into it, and don't plan to sell the current diff so I can sell it with the car later.

Wish you lived around here, I'm trying to sell my stock open diff.

You only need the stock diff/carrier. Although you should probably pick up a new set of axle seals, they're only like $15. And you'll need oil for the diff carrier.

I'd just post a "WTB" add on Craigslist. I'm asking $100 for mine, I figure that's probably a fair price.

Oh, and if you've never removed the diff before, detaching the upper A-arm helps a lot for getting the half shafts clear of the diff. And you'll need a pull-hammer to get the stub shafts out.

If you were closer to me, I would give you a straight trade. My open stuff for your torsen

thatsnowinnebago wrote: If you were closer to me, I would give you a straight trade. My open stuff for your torsen

db wrote: I don't plan to sell the current diff so I can sell it with the car later.

Car is a '95 so I believe it is a Torsen unit.

Gack! Isn't trading a Torsen for an open diff, like, blasphemy? As others have pointed out, the original Torsen is indeed stock class legal.

If the '95 came from the factory with the Torsen, keep it in there. Unless you're really set on running an ST class, where I think limited-slip diffs are outlawed. You can still run ES--you'll only need to spend thousands on shocks and race tires to be competetive (in a stock class).

If you still want to sell the Torsen, don't take less than about $700. Or swap someone for their open diff, and take $500 additional cash. If you have to pay someone to do the swap, then you may want to make it closer to an even trade.

You've got one of the best differentials on the market; don't give it away. Join your local Miata club. Someone there will help you.

So after reading your first post more carefully, you shouldn't have to pay more than a couple hundred for an open diff. www.specmiata.com will have a few people that want to sell their open diff. Buy the entire thing, from rotor to rotor. It should be an easy swap.

You could probably use your ring gear, but would need the stub axles for the open diff. I'll dig around as I might have an extra set. PM me if you're interested.

CGLockRacer wrote: You could probably use your ring gear, but would need the stub axles for the open diff. I'll dig around as I might have an extra set. PM me if you're interested.

I wouldn't bother with that. If you disassemble the internals of the diff, you're going to need to set the lash and other crap like that will require specialized measuring tools and a lot of patience. It should be just as easy, and no more expensive to buy a whole pumpkin with an open diff, in which case it's already set up right.