A/R 0.60 0.82
Inducer 55.0 mm 56.5 mm
Exducer 76.2 mm 53.5 mm
Gods turbo I dont know... there are a whole lot of options for a gt30. What 40 to 60+ comp?
Also, since noone has a gt28 on an sti, we don't know how the responsive it will be.
I dont think its a stretch of the imagination to guess at how responsiveive the gt28 will be on a 2.5L; hell on a 2.0 even a 1.8 its very quite nice.