i had a kind of loud muffler on my gs for 2 years and i always liked the sound. but now since i've had the stock exhuast on the GST i realize i really like the quietness of it better, sooo....is it useless to get a 3" exhuast system and put a silencer on it. does the silencer effect the airflow that much or will it still flow like it wasn't there?

A silencer destroys airflow. It would take a 3" exhaust down to about a 2". Possibly smaller.

that's what i was lookin for, thanks. i guess i'll have to sacrafice a little noise when the time comes.