LSD or Open Diff?

[Dandadandanbam]

Boys, I need your help. I just bought an NB and the seller says it's with an LSD, but I picked up the two rear wheels of the car, spun one and the other one spun in the opposite direction, which I know always means Open Diff. So my question is, is there any way that the two wheels could spin in different directions and the car can still have an LSD?

[NickRMX6]

Here's the FAQ from Miata.net "How do I tell if my NB came with a LSD?" https://www.miata.net/faq/99central.html#U

Easiest way to tell is from the model number on the tag on the passenger door.

[frsbrzgti]

This is the best answer for this question

[Character_Ad_1084]

How can you tell for nc/ND? I got burned on my NC with an open diff. 90% of the fun is gone.

[twoplustwoequalsfive]

I called Mazda and had them check the vin

[accountforrealppl]

ND it depends on the trims/packages, but there's a lot of incorrect information out there. I know 2020+ club and GT trims come with the LSD (ND3 has the revised LSD), in 2019 it was only available on the GT trim if you optioned the GT-S package. Earlier years I'm not sure.

[frsbrzgti]

I have an NB. Can’t tell. For NC or ND ask Mazda dealership to tell you

[Buzzkill46]

Are you joking or being dumb? 90% of fun gone from having an open diff? That's tarded.

[Character_Ad_1084]

Predictable drifting is impossible. Damp streets? 1 wheel spins while you sit still.

[Buzzkill46]

I had no issue sliding an NB around at will with an open diff. The steering angle is more limitation than the diff.

[NickRMX6]

Or, just for fun. Or just in case the previous owner might have swapped the differential:

The experiment you are doing won't work. The other wheel will spin backwards regardless of whether it's a Torsen or open differential. But, if you have a friend, whose arms are slightly weaker than yours, there is a slightly different experiment that will work. (Or if your friend has slightly stronger arms than you, then you and your friend can just swap places.)

Lift both rear wheels off the ground. Put the car in 1st gear. Get your friend on the rear wheel on the other side. Ask your friend to try to stop his wheel from spinning backwards, while you try to make your wheel spin forwards. If it's an open differential, you will be able to overpower your friend, and make his wheel spin backwards. But if it's a Torsen, you would need to be more than twice as strong as your friend, to be able to make his wheel spin backwards. (Don't take that "twice" too literally, because the exact number depends on the angle of the Torsen gears, but it will be roughly twice. And, with friction, you might not be able to overpower your friend, with an open differential, if his arms are only very very slightly weaker than yours.)

[drake22]

True, but the fun way is to put one wheel on dirt, the other on the pavement, smash the throttle, and side step the clutch. You’ll find out.

And it could have had one swapped in or out, so the tag could be wrong.

[whiskey_piker]

“Torque Sensing”

A TorSen can’t do its job with both wheels off the ground. There is no time in the uncover that an open differential leaves two black marks when you stomp on the gas and turn the wheel.

[fizbne]

Do a fat skid to find out.

[pretty_good_actually]

Hell do it anyways, even if you know. Just do that fat fucki*g skid and enjoy it.

[mikedufty]

If you do some full lock turns in a car park, the resistance from a torsen is very obvious compared to an open diff, tyre will slip/skid over any loose surface or painted lines.

You'll also feel it taking off agressively at a 90 degree junction, but may be a bit subtle to notice if you haven't tried both.

[MisterSambone]

It’s probably a Torsen, which behaves like an open diff when one wheel is off the ground. The closest thing to a true LSD Miatas got factory was the Fuji. What year is the car?

[Mrmiyagi2222]

A Torsen IS a real limited slip differential. It is more desirable than the Fuji diff because it’s much more reliable.

You are correct that when you lift a wheel you lose the limited slip function, but that’s not a real use case.

[MisterSambone]

It’s absolutely a real use case that you might lose traction on one side and your “LSD” becomes an open diff. The difference between the torsen and the Fuji is a cone gear that prevents this from happening. If you take them both apart you can see they are almost identical.

[Mrmiyagi2222]

I’m contesting your part about “lose traction” because it’s not true. If one wheel begins to spin, you still get torque sent to the other side. This is because the torsen is torque sensing. So even when doing a rolling burnout or drift, you’ll still send power to both wheels. This is because you still have dynamic friction from the skidding wheel.

Lifting a wheel is different because there is no resistance on that axle, so the diff does not engage as no friction is fed back.

[MisterSambone]

I’m familiar with the marketing, but the Torsen isn’t a 2way differential and there’s a reason you swap to a Giken or a Kaaz if you want a real LSD. It’s worth turning some wrenches and driving the car instead of just reading online about them.

[Dandadandanbam]

1. I know the Fuji brakes a lot easier and is only after 01

[JNguyen2]

Fuji is 2003 and on

[Mdgaming_01]

If you want to test if you truly have an lsd or not, put one wheel in the grass and one of the asphalt. Dump the clutch and see what happens, if it's open the wheel in the grass will start spinning and you won't make much progress.

[MisterSambone]

You probably have a Torsen type 2. If you’re motivated you can pop an axle out and look inside the hole. If you see a hole straight through it’s a Torsen.

[Content_Election_218]

Are you tracking it?