A port 1" wide by 2" tall has a cross section of 2 sq. in., 2 sq. in. port will support a :
230 @ 7000 RPM 250 @ 6400 RPM 292 @ 5500 RPM
after this RPM the port will go sonic and VE will drop. this is a rule of thumb, you really need to measure the air speed to know what it is, you do not want to go over .6 mach