Banshees dont have a rev limiter so i dont know what a cdi is gonna change. As for the Dyna FS im sorry unless you have nothing else to buy i think its kinda stupid. Shaved head 50$ timing plate 35$ you get the point there are alot better things to get than that. Shit get porting if you gonna spend that kinda money. All in all for alot less money you can get way more power save somthing like that for when you already have all the other stuff. (porting, stroker, cubs, so on so forth)