I recently bought a 14' si coupe and was wandering how much power would be lost if I just did dp,cai,and tune? Basically I'm thinking of the rv6 or full race dp, acuity cai. Or should I just go with a cat back as well? My main concern is noise, just really excessive, and clearance. (I did use to have 3" on my 99si as well. )since i plan on lowering eventually as well. Any feedback would be awesome!