MarkEmark wrote:Anything over 60mm (about 2.25") is useless for our cars unless they're turbocharged...stay away from the big piping, even if its only 2.5". Dual N1's are WAYY too big for NA...you want SOME exhaust velocity...big pipes mean slower exhaust gas velocity, especially on a stock engine, and you want such gasses exiting your engine as quickly as possible.