It increases the area if you were to imagine a plane that is the entrance cross section to the port. So basically you have a transfer that has been enlarged so you need a opening to it that is larger. Normally the main transfers are larger or sometimes have longer durations and height so that explains the larger opening on the main vs. the secondaries. That is a pretty drastic difference but I dont setup 500's so I am not one to say whats good or not. |