Side vent help.
 

These are the side vents that are on my boat now. I am molding up some new vents using fiberglass using the NACA style vents to try to force more air in. My question is do I just force air in or do I need some place to vent the air? Should I force air in on the side and exhaust air out the back of the boat with some vents? I have found that my boat runs much better when the engine area is still cool, once it heats up the boat slows down some. I figure the current vents don't draw any air in at speed other then what the prochargers are sucking in.