I have read 2 1/4" diameter will support 400 hp. Any idea on how much power might be lost going to 2" diameter duals.
2 inch will be much lighter, leave more room and allow the use of quieter mufflers!
More than likely the mufflers will kill more hp than the pipes, ideally you want zero back pressure, if you already have an exhaust you could measure the back pressure and guesstimate from there.
