Which Nissan LSD diff for track work?

I'm looking for a short-geared diff for a project car. Nissan diffs will physically mount to the subframe and are available in a huge number of ratios. Tons of companies offer performance LSD options, including factory Nissan motorsports stuff.

So, here's the question...

In order to fit my subframe, I need an S13 240SX diff cover. But, based on my preliminary research, that doesn't mean I need an S13 diff. I can use the diff from a 200SX (S13 or S14), a Skyline GTS-T (R32 or R33), or a Skyline GT-R (R32 or R33).

...which one would you choose?

Is there a difference between 200SX, 240SX, R32, R33, etc? Are some stronger than others?

Diffs among Nissans are known by their ring diameters in millimeters: the most common ones in early '80s cars are the R180 and R200. That should help narrow the search. 280ZXTs and 300ZXTs normally came with the R200.

I bet the Skyline ones are the strongest due to the fact that they are putting out the most power. Nothing scientific there, just gut feeling. There are lots of 240sx LSD's available aftermarket, that might be the most straight forward route to take.

In reply to sethmeister4:

Strongest would be the R230 out of a Q45, unless there's something from a truck that is both independent and larger.

If money isn't an issue, Quaife apparently makes a torsen-type diff for the R200. I don't know if there's year to year differences in this diff that makes one donor model or year better or worse than the others.

I have beaten the hell out of several of the r200 240sx diffs. Unless you are installing a lot of power I think they are all bulletproof. I would suggest picking a diff that was available in a few different ratios. The 240 sx diff is not. You have to install a new pumpkin and half shafts to change the ratio unless you find one of the rare 4.63 gear sets that nismo sold for a while.

In reply to pres589:

230mm is a hair over 9 inches, for the metrically challenged, so the Q45 diff would probably be stronger than anything you would need, and being a big RWD luxo barge, factory LSD perhaps?

In reply to Kenny_McCormic:

Most of the Q45T's were LSD, but not all. Definitely a good one to get. Also most of the J30T's were LSD too...I know the 240 guys like to swap them in.

pres589 wrote: I don't know if there's year to year differences in this diff that makes one donor model or year better or worse than the others.

Yeah, I'm not really sure where to start. I'd like to be able to swap ratios without too much trouble, if possible.

Hoping some Nissan folks will be able to point me in the right direction.

The R200 will take anything you can throw at it. There are drag cars making sub 10 second 1/4 mile times on stock r200s. They are absolutely bullet proof. I always joked around and called it 'the Nissan 9 inch'

Find one from an S15 Silvia, its a helical diff (AKA a torsen)!

In reply to Spoolpigeon:

http://ziptiedz.blogspot.it/2013/07/r2oo-lsd-ripped-apart.html

I would go with an R200. The Japan only s15 came with a nice helical unit, about $500 going rate. Much cheaper than quaiffe and track proven. You can also get many clutch type units from aftermarket companies like Kaaz, Cusco, etc. Many oe gears available. 4.08 stock in 240sx, but Nissan trucks and suvs used 4.36, 4.63, and 4.9 as well, in front differentials. Search for specifics.