Confusion over my car's type of differential, i know...
 

Did my 2nd Gen RX-7 come with a Limited Slip Differential?
Only the following USA model 2nd gen RX-7s had a LSD from the factory:
86-88 GXL
87-91 Turbo
88 GTU
89-90 GTUs (however not the 89-90 GTU)

I know about the FAQ section and the information above is an exact copy of what's in there. So it should have answered my question, but I've been told different. I have a 1991 RX7 coupe NA series 5 and what I've been told is that my car does have limited-slip differential and without referring to anything except for the lug nuts (there are 5) this individual assured me that's what I have. I'm sure a number of you could give me a definite answer to this question. thanks

http://i769.photobucket.com/albums/x...7/IMG_1309.jpg

If you do it did not come from the factory. Go do a burnout and see.

5 lugs does not automatically mean LSD.

jack up one side and spin the tire, if it easily spins with the trans in neutral, then the diff is open.

if its hard to spin by hand, then its LSD

a 91 NA should be open diff

Look under the rear of your car and look up at the diff. If it has a tag on the fill hole that means it is a limited slip diff. Assuming your diff is stock though, it should be an open diff.

hmm funny thing about that is in my car with an open diff i did a b stand one time and had both tires smoking.

Tag is often gone. Don't rely on that.

Jack up the rear (both tires off the ground). Put transmission in neutral. Spin one tire. If the other tire rotates opposite it is definitely an open diff. If the other tire rotates the same direction it is likely a LSD, but it could also be an open diff with a mechanical problem.

Random 91 non-turbo cars had the LSD it was an option only for non-turbo's of that year (also part of a package).

But, more 5-bolt cars were open diff than not. That is DEFINITELY not an indicator.

Another way to tell is when you jack up the car, a N/A open diff will have 9 vertical lines on it. A LSD one will have 11.

If those are the stock rims for your car and you don't have turbo brakes, that means you have a GTU, not GXL or GTUs which means open diff.