a nitrous controller that could allow you to have an initial 100 or more burst then taper off a bit once boost is high would be best. dont know how well it would work with zex but people do that alot with nos kits. are you in wentzville missouri? my buddy shane works at autozone and always tells me that he talks to some guy with a stage 3 s4.

 

yes i do live in wentzville ask what color it and weather or not it is tint as me and my buddy both have b5 s4 and his black just like mine but his is tent and debadge and mine aint ...funny story whenever him and i firsted raced