This is my second set of Thrush IGUs. My first set was 2.25" intake/exhaust when I upgraded my exhaust system to 2.5". I bought them again. I like their sound, plus there are no baffles or other obstructions in the exhaust flow, they are free flow mufflers. They have a deep tone rather than a throaty or tinny sound. I know everyone has their own preferences but you can undercut the price of a loose silencer like the Thrush glass packs. just rumble. ! The original 2 inch pipe setup was more modest. Now I attribute the roar to the larger pipes coming out from behind.