I finalised the Cobb AP etune on my WRX today, courtesy of Phil (philr8) at Dynotech Industries in New Plymouth. Very easy process in the end over about a week, and produced results I am happy with from the FA20 with only a Cobb catted j pipe and exhaust (in line what others around the world are getting with a custom tune and these mods: about 280-290whp). The final virtual dyno (green line):
From what I've read, I'm approaching a wall with the torque as the stock FA20 doesn't like much more than 470Nm, but an intercooler upgrade might help drivability a bit, as I've definitely noticed some issues with heat soak over the last year.