OS Giken?
 

I just sent the ? to Craig W. (OasisT) but looking for opinions on how much faster the OS Giken LSD might be than the Quaife I already have in my R53 on a typical ax course? Would it pull faster 60 ft times at a Pro Solo as well? I think I'll be needing a clutch soon which is what got me thinking about it. Does the Giken typically need to pulled down and adjusted? What should I get for a combination Street/Ax car a 1 way, 1.5 way or 2 way?

tough to say exactly what kind of differences you'll see. a lot will depend on your setup, how much power you're making, etc.

http://www.scienceofspeed.com/produc...The%20Diff.pdf

you definitely don't want a 2 way, at most 1.5 way or "1.3" way if it can do that. that's just a matter of how much lock up you want during deceleration. typically though, i think fwd cars or front axles they use a 1 way.

I am still looking for feed back on this. How much faster would the Giken be than a Quaife on the average autocross course? Even more specifically a Pro Solo course?

There is a company in Northern Ireland that can build you a custom LSD based on your driving style and courses for much less that OS Giken. They would need some videos of the courses and a video of your driving. PM me and I can put you in touch with the owner.

http://momentummotorsportshop.com/

When I did a clutch in my r53, I asked my setup guy for a LSD suggestion. He said OEM/quaife was fine unless I was already competing for overall pax at local events. You gain a few tenths on a run during the low grip corner exits. You can put down power where you would normally get wheelspin. The downside is that the car is completely undrivable when using parking lots for their intended purpose.

I think a 1 way diff is the right choice because you don't want to make corner entry any harder. Have you called OS Giken? Jon Lugod campaigned a FWD car in STX for a few years so he probably has some good suggestions.

I actually made the switch from a Quaife to a 3J driveline witch is a clutch type lsd. I can't give you a time difference but I can tell you it made a difference for me. Im in SMF and made 244whp for 4 years. The Quaife would spin the inside tire all the time. Depending how much your into it, it would be worth it. Every 10th counts!