MY07GTB engine VS MY08 STI engine

[Jaz]

I'm interested in the specs that make an STI have more power than the Liberty straight out of the box (184kw vs 221)

FIrst things to come to mind are the Turbo, (?VF52) and intercooler, but I'm interested in long motor specs too

Head Design, ?Cam specs, AVCS in and out?
Piston design and material
Header system?
Manifold? Does the STI have the tublers deleted?
Injector size?

Any other glaring differences I should think of? Tuning also needs to be considered, but that's a given.

[PoidaGT]

I believe the WRX STI (08) engine has a bigger ball bearing turbo (VF34) bigger intercooler, higher flow heads, bigger cams. Not sure about pistons, rods crank etc.
You can get the 07 Liberty GT to around 220kw (flywheel) with a 3 inch Turbo back exhaust system and a good tune.
300kw at the flywheel is about the highest you can go before you start melting pistons.
The weakest point for both engines is the pistons which need to be replaced with forged units to chase the big KW applications.