We I have bought a cartridge of a S480 and some day I need to get a exhaust housing and I remember some one talking about using the smaller housing for use with stock turbos. So with a goal of making a better dd and keeping my engine together of a couple more years, so lower power level like 650 max, what is the better option. I know with twins it is hard on the bottom end. Is there any other options? Also I am on the look out for a compressor cover for the S480.