If You want more for an example that "flow" as the primary factor in the exhaust really isn't, watch the Freiburger & Dulcich vid "Header Bash", the high energy-low density gas is most affected getting around the valve. After that, a great seal & proper tube size/length to utilize velocity is king, even with some kinks & dings. If You wanted the best flowing exhaust, You'd want a large log w/a sewer pipe off of it, one large pipe has way less surface area/frictional factor than a bundle of small-long tubes. It would handily out-flow a header set, yet We all know which one will run rings around the other........
