I have Driven a car (32 GT-R) with headwork and GT-SS making around 300AWKW and the thing is a monster, through the mountains it allows you to pull idiotic speeds even through the shorter sections...
Slightly off topic, I see that Garrett rates the -9 at 310HP per unit but it surprises me more people, especially those with forged bottom ends arent pushing the 350KW mark.
I know that Giant on here made 400kw on similar size turbo's admittedly with race fuel but race fuel isn't worth 100kw.
It's very interesting to see the different results people are getting with these turbos.