I know I'm gonna get a bunch of smart butts but I HAVE tried using the calculators off the Internet to figure how many square inches of port I need and how long it needs to b but I can not figure it out.. I just got a DC LVL 4xl 15" and built a 3.3 cubed box.. That's as big as I can go right now and now I all I have left is to cut the top of the box but I need yalls help with how big my port needs.. I can go 16" wide and my box is 18.5 inch tall.. Thanks
