Originally Posted by 09rexwagon
The 06-07 WRX have 3.7:1 FD ratio. You need 3.9.
However the VC in the pre 08 WRX r160s really aren't for performance but for inclement weather driving. VCs transfer torque based on speed differential and are very slow to do so in addition to the fact that the VCs in the r160s are weak anyway.
What sort of driving do you intend to do? Autocross? Track? Why are you so concerned about having 2 tires off the ground?
You were recommending a quaife or OBX diff. Do you have any idea why the diff manufacturers don't specify anything past 07 for the R160? I've read somewhere that the differential case may need to be slightly modified for the Cusco diff.
Also, reading this thread http://forums.nasioc.com/forums/show...ghlight=ratios
if this is correct, do you have any idea of the difference in compatibility from an 04-06 or 07 STI rear end in a 2008-2011 car? Just wondering if all the mounting, stub axles, and drive shaft are compatible.