1.8 torsen diff
 

What is the failure point on the torsen diff available on the 97 miata and could this part be upgraded ? Trying to avoid looking for an rx7 diff

"the" failure point? WTF?

I mean what part fails

Your ability to stop wheel hop. Thats what fails. Seriously, they don't break under even moderate power and track abuse. Wheel hop with slicks and 350 hp break them. Sustained track use with excessive temps from underbody mods kills them.

There's also the 'break seam' that they have where they crack if they're in an impact.

running backwards into poles also breaks the impact seam.

Not doing so sounds like a cheap upgrade!

I gonna be dragging the car a bit i m only making around 250 now but i m building another engine to support hopefully 500+ so i guess the rx7 diff and tranny is better

8.8

If you are going to be doing massive burnouts and shit I'd get a hyper-preloaded rx7 clutch type and swap it in.

The failure point for torsens is giving them to Aidan. He breaks them at the strip with measly 1.6 powah.

So they don't break much, but do they wear to the point of being ineffective?

Sure. After 300-400k miles.

You can lunch one pretty easily if you're putting down a bunch of power and have wheel hops etc. At that point, you're probably already looking for different trans options so you have to figure something out anyway.

A torsen does not wear out, ever.

They will literally outlast humanity. Future beings will dig them up and immediately have a way to sense and deliver differential torque.

Sneaky OBX
 

I had thought that I had a Torsen in my 3.6. And whatever it was, was clearly shagged. I separated the diff a few days ago, and what I found was a helical diff, but it looks like an OBX brand. The amount of slop suggests there can't be much left of the washers.

AFAIK, there was a modification someone fashioned that prevented that.

Yes - have found that. Upgraded washers and fasteners

I've got an OBX that I rebuilt. I bought it used and it had previously pulverized washers when I got it. After rebuilding it and reinstalling the sun / planet gears the correct way (they were installed backwards from the factory), it's worked flawlessly for me for the past 50K miles. There is a good chance that the sun or planet gears may have gotten chewed up in yours though depending how long / hard it was driven on up to this point though.

My diff is fine but i m preparing my self for more power and i need to make sure my diff will handle it

the hexi-coil gears are the weak link. they can shear off if you drag race your car on slicks.