Kevin Allen wrote:
Oh, yeah - forgot to mention that you may have to switch to a push-type clutch with the FXT transmission. 2.5RS transmission is the same type as FXT, so same deal.
I've seen a few JDM STi transmissions for sale on various forums - nasioc, iwsti, rs25, that are basically the FXT transmission but with a pull-type clutch.
And there's a thread on nasioc in the transmission forum that details how to swap in a USDM STi 6spd for about $3000. Been thinking about this for my WRX - which is one reason I should sell it.
04-05 FXTs are pull like the WRX

so it's a straight swap, but you'd need the 4.44 R160 rear diff from the same car or you'll fry your center diff. The WRX has a 3.545 rear ratio with a 1.1:1 xfer ratio for a total of 3.90:1 FD.
For tranny's, the 08+ WRX have the strongest gears (same gearset as the V6 JDM STI 5 speeds) but they are really long (not good for rallyx). They'd be nice with 4.11 or 4.44 gearing, but with 3.90, it's just really long for rallyx (maybe desirable for track). If you get a 05-09 Legacy 2.5GT tranny and rear diff, then you'd have the same gearset but with 4.11 FD gearing. With these options, you'd need a new clutch, pressure plate and TOB and a different slave cylinder as these are push style clutches. Also you'd need the rear diff from what ever car you get it from since these transmission have a 1:1 xfer gear ratio so you need the 3.9, or 4.111 rear diff (not 3.9/1.1 or 4.11/1.1).