OK t5 work better with mods and t6s work better with less modifieded banshee t6s creates more low-end and mid-range power the T6 is 8 hp over T5 on top end, and 5 hp over T5 on acceleration, thye put out around 55hp in the midrange. Both very good sounding pipes but t6s might be a lil louder but if u plan to do work to motor stick wit t5s .Hope this helps.