I know that N/A's so difficult to tune to get any real gains and only way for bigger power is charging but it is so expensive. I am happy just to get a few bhp more to get closer to the 275bhp mark.
High lift Cams, and mapping will get you to 275bhp
I got 276 on my mk4 from:
Techtonic cams (260/264)
200 cell sports cats
Milltek back box
Kn panel filter in factory airbox with drilled holes for extra lols
I suspect with higher duration cams from the likes of schrick will gain a few more HP too.
As it is, my car made maximum power at 6800/6900rpm, which is a decent increase over the stock power limit which is around 6000-6200rpm. U can rev the engine that bit harder than stock and it delivers the extra shove