Quoting fuel:
01420 (Galant VR-4 Evolution) 16G is the same as the Lancer Evo1/2 16G. Lancer Evo3 16G has a different compressor wheel (still the same 16G dimensions just different design of blades) and a better turbine housing.
This plus material type.
Rotating assembly is about 2-lbs lighter on the REAL, not knock-off, E3 turbos. Faster spool basically due to lower rotational mass. IIRC the exhaust wheel is Inconnel and the center shaft is titanium or the like.