yeah, top end power does drop off a bit too fast.
with my rb25 turbo i have the same amount of power at 8000rpm as i do at 5350 rpm.
most probly due to your runnin a lot more power than me...
i only pulled 156rwkw on the dyno in adelaide that sam used that reads low.
very interested in this turbo though, was lookin at it a while back cos i saw a dyno sheet with a very linear response but still had lots of top end poke.
hks kit is a bit expensive though, might go the highflow (gt2871r) in the rb25 housing, .63 a/r, should be pretty darn similar