Is there an easy visual way to identify a torsen?
 

As I'm starting to shop for a miata, i'm wondering if there is a simple way to identify a torsen from underneath. I did a search in this forum, and don't see anything. I did see that I can call mazda with a vin to check, but since i'll be looking at cars in person wondered if there was something simple from underneath.

If your search to find how to find a torsen didn't work, then your search to find a person to tell you how to find the post to find a torsen won't work either :). Search google, there's a good one on Miata.net I think.

I found this

http://www.miata.net/garage/diffguide/index.html

but its still a little wishy washy. It seems like the damper has to be there for a torsen, but i'm not sure that the damper being there guarantees it being a torsen. Theres also a bit about the "ears" on the stub shafts, but they are mostly talking about 1.6s

Easiest way without taking anything apart?
Punch it mid corner and see if both wheels lock up and spin resulting in car getting sideways ridiculously easy.

Negative but close, go to a parking lot that has a big empty area. Turn the wheel at full lock which ever direction you are most comfortable doing donut/drifts. Punch it in first and let the tail kick out. If you can keep it kicked out while bliping the throttle on and off its a torsen. If the minute you let off the gas it snaps out of the donut its a tragic open diff. Dont look at tire marks as both can lay down 2 tire skids. I've probably used this to identify rear ends in 10-15 different miata's with out fail. If your not a good enough driver to cut a drift/donut or can't keep it hung out in a tight circle than you really don't need a torsen anyways so idk.

I think the bigger issue is how a seller will feel about me doing that on the test drive :D but thanks, it does make sense.

Your literaly going around 1 time. Its your $800 gamble.

Yeah, I guess if I am ready to buy a specific car, then I tell the owner exactly why i'm doing it. or offer him jacking up both rear wheels off the ground, and trying to spin both shafts in the same direction at the same time (which shouldn't work on a torsen)

Since when do used-car sellers not allow you to test drive the car by yourself? Hand over your keys to prove you aren't stealing it, and go hoon that bitch for a few minutes.

Yeah, especially in a 2 seater. Haven't shopped for a 2 seater in a looooooong time, so wasn't thinking about that :) I'll bring my wife along so theres no space for the seller ;)

I'm pretty sure that they both act the same when on a lift. The only visual inspection requires pulling an axel and looking inside for the bar.

Is there an easy visual way to identify a torsen?
 

No.

There's no way to visually tell without disassembling the diff or pulling a stub axle.

I thought if it had leather and a manual it was a Torsen.

If the car was orignially equipped with power mirrors, then it was originally equpped with a Torsen from the factory (if it was a '94 or later). The exception to this rule is the 1997 STO, which was Torsen-less.

15 years later, who the hell knows if a previous owner replaced a torsen with an open for any number of reasons:
Side impact at the rear axle tweaks diff gears which later self destructs due to misalignment.
Dude's friend has an open and wanted to swap him for $200 + a case of beer
Replaced with an open for Spec Miata classing rules

Plenty of non-leather cars had Torsens. A good indicator is cruise control - if it has cruise, it has a Torsen. No cruise, no Torsen. It's not perfect but it works for most years.

M.net has a good year-by-year breakdown of the packages and what cars came with torsens.

Since people like you started joyriding the fuck out of them and since people stopped trusting other people.
Good luck with that.
I've yet to see anyone around here let someone test drive their car alone unless its a complete and utter POS.

this is completely untrue.
unless you're talking about n/a's only in which case I'm not sure.

but there are tons and tons of nb's with power windows/mirrors and no torsen

Bore scope my friends works great open the filler plug and put the camera in and see. That how i knew i got a torsen on my last miata.

Remove the oil fill plug (upper) from the aluminum diff cover. Shine a very small flashlight into the hole, and look into it. Do you see worm gears? Then it's a Torsen.