the good thing is, all good cars have lower than real hp. that gentlemens agreement dosent only apply to japan. for example, the 02 SS camaro has closer to 350hp from a rated 325. albeit not as much as the 276 to 320. would it be possible to get a prodrive ECU? ive heard that prodrive is only a few odds & ends that they tweaked. that would makes sense b/c there's really not too much more to do w/ the stock setup. you have the japan edition so check w/ prodrive. try and get it sent there before you get it sent to you. what a treat, you're at sea level or close right? lots of O2 for that turbo to inhale. you might get more hp w/ all that oxygen density.