the pipe is just to let the water come out the back of the hood instead of the water having to flow out of the front of the hood while moving forward, im not expecting all the air for the engine to flow through those pipes. i still have the front hose in the stock location, which is all i have used for 2 seasons (ever since i have been running dual carbs). I plan on drilling another hole in the same spot on the other side of the hood liner for additional air. I still have the vents on top of the hood open.
My biggest problem was after stabbing the ski would bog really bad since the water in the hood had no where to go once the ski got moving forward and forced it into the bilge. This should eliminate this.