Here's the link I was looking for the other day. These are the diffs that I am aware of and why I was asking my previous question.

http://www.classiczcars.com/forums/showthread.php?s=&threadid=1568&perpage=15&pagenumber=2

I've got one of those R180 3.9 units that will be going into my car and if I can get an LSD R180 3.9 that would be even better!!

I'm still a bit confused texasz. It sounds like you just want to know how the different LSD's function. It's complicated and I don't want to write it all out, but I found some links for you.

This site explains how the Nissan/Power Brute diff works:

http://www.gordon-glasgow.org/lsd3.asp

Actually if you want more info that start at the beginning of the LSD section and read all the way through. That site has the best breakdown of the Nissan clutch LSD that I've ever seen.

I couldn't find a good explanation online of how the Quaife works. I did remember an old thread from Hybrid Z where I argued with some other people about how it works and which was better, etc. It gets into the Torsen more than the Quaife, but they are very similar in the way they generate friction to limit the slip. It's a long thread and some of the picture links are dead, but here it is if you dare: http://forums.hybridz.org/showthread.php?t=93879

Bottom line for me is that I think the clutch type is better, and 1/3 the price. Can't beat that! I'm aware that I am in the minority on that opinion, but my opinion comes from seeing racers install the Quaife, have wheelspin or break axles or both, and then subsequently remove the Quaife in favor of a clutch type LSD. Plenty of people disagree with me on that one though, I am definitely in the minority with my opinion.

If you're putting one or the other in a street car, you'll probably never notice the difference between the two, and either will be a HUGE improvement over the open stock diff. The first time you go around a corner and stomp on the gas you'll know you did the right thing.

Jon, I am not looking to learn the details of how an LSD works...just looking for one for my Z in an R180 3.9 configuration.

So what's the trouble? You can purchase one through the group buy on Hybrid Z or you can buy one from Quaife, or Nissan. Could also probably get a KAAZ or a Cusco.

Then the Brute Force buy mentioned earlier is the answer for you if they can hook the R180 guys up for the previously mentioned price.

They were out of the R180 Units when I talked to them!! But, I have a R200 3.9 open looking for a good home, I need to go with a R180 because of rules(SCCA).

Trades?? Sell??