I pulled this out of a "JDM" S1 tranny that was built by a local drag racer, supposedly it's an OEM differential, but I don't have a clue.

Here is the teeth count of all of the gears that were inside the tranny:
1st main, 38 teeth
1st counter, 12 teeth
2nd main, 39 teeth
2nd counter, 19 teeth
3rd main, 34 teeth
3rd counter, 24 teeth
4th main, 32 teeth
4th counter, 29 teeth
5th main, 27 teeth
5th counter, 31 teeth

Differential, 64 teeth
Final drive, 15 teeth

So...here are the gear ratios:

1st - 3.166
2nd - 2.052
3rd - 1.416
4th - 1.103
5th - 0.871
Final Drive - 4.266

 

Just going from the looks of it, it almost looks like a ATS LSD, I'm not positive though so don't take my work.

EDITED: spelling once again.


Modified by Kataku2K3 at 10:55 AM 5/30/2004

 

doesn't really look like an ats. ats looks exactly like a kaaz. i never seen an lsd like that before.

 

I've never seen a factory lsd out before, is it possible thats a Y1 trans w/ a factory LSD since the Y1 did have a 4.26fd and the jdm si did not?