My dad wants to get a pipe for his 450es but he doesn't want it to be to much louder then stock i was thinking maybe the super trap IDS2 or the big gun quite or something like that?

 

I got a supertrapp on mine. Its not them best made pipe but it gives alot oif performance. I took out 6 disks in mine and it perormes i credible from 1st to 5th. Get a kn and dynojet kit with it for maX results. Not to loud either its a nice sound.