I don't damp my exhaust ever. I think that you will find that the vast majority don't. For me the smoke flavor is way over the top with a damped down exhaust. I get all of my control with the intake air. You can have too much exhaust but 2 inches seems just about perfect. i seem to remember someone telling me that 2 1/4 was ideal but I had a piece of 2 inch pipe laying there so...
Hot Rod Hog Cookers Association, Charter Member, President