Correct on the Greddy plenum... I also investigated this and found the same information. The stock plenum works fine though up to about 600hp, it just doesn't look as cool as the greddy plenum :lol:
lol then i must have some kind of freak turbo because mine sees 0.9 Bar every time i drive it, and it's been fine at that boost level for over 18months, with a few track days too B) New HKS GT series turbo coming soon though