I'll offer three comments and then back away and let Tech run 1) Set your engine up for power and efficiency and the sound will take care of itself. 2) Biasing your decision on any part to achieve sound at idle is one of the biggest mistakes you can make. 3) Open your mind and listen carefully to Tech. He knows of what he speaks, and if you follow his advice you're gonna have a perma-grin that won't fade for a long, long time.