350 AWHP depends on tune, dyno, so on and so forth. But I run a Blouch TD06-20G with TurboXS TMIC, Walboro FP, DW 850CC injectors (a tad overkill, but room to grow), Cobb TBE, Cobb SRI (w/box), Ingarsol Rand 3 port BCS, stock range spark plugs. Made 329 AWHP, 319 ft/lbs tq at 20PSI on a Mustang dyno on 92OCT in Puyallup WA last June. Car is a blast to drive with no real noticable lag. And I have room to grow with both the injectors and turbo (with current TMIC).
You will be happy with the turbo. Check out blouch's site, they have a "newer" and "better" 20G then what was out when I picked mine up.
And the intake isnt needed unless you want to run a CAI, my tuner tuned my car wtih the Cobb SRI as if it were the stock box.
"2007 WRX- PPG'd, 20G- Tim Bailey tuned
Stage 2 2005 WRX
Last edited by newtothegame; 07-14-2010 at 12:34 PM.
Reason: Added a side note