With the mods I have now its not a ton of power increase. I'm still noticing that its only pushing about 8-10 lbs of boost at WOT. Which isn't bad, the turbo spools with nearly no effort which is nice. With what I've done I've felt (haven't dyno'd yet) a quicker throttle response, and it seems like it got a little more torque than stock. I've seen stage 3 ST's (intake, exhaust, Dpipe, FMIC and a decent tune) push about 280whp/375tq on a dyno with a stock K03 turbo. So it all depends really.
First impressions though after owning this for a week? Pretty impressive little car for what it is. It will be fun to see what it can do down the road
