Just got the transmission done and now I'm thinkin' of more power :-laf ? I was looking at Mach 4's and a bigger turbo. I've spent hours lost in the "land of turbos" on this site and still haven't decided. I think I'll give HTT a call. With my current sig and 4's and a turbo upgrade... what kind of HP will I be making. I'm gunning for 500+. Also what else can I do as far as other boxes or ecm's. What's the whole deal about stacking boxes? How much more would a MAD ecm add. Thanks