Quote Originally Posted by simontibbett View Post
That's a poor "domestic" example since it's a Le Mans GT car. The radiator on those is also mounted in the rear, or is now, or was. Not sure what else is up front or if they're just controlling the air. Escaping air = using it. Of course just allowing it to run free would not serve any real aerodynamic purpose.

A cowl hood on a muscle car can serve the purpose of getting air into the carbeurator, that's what I always thought they were for anyway and mentioned above.
Ultimately, the goal of any air that passes through the hood is to cool the radiator. Anything else gained from this is an extra. "escaping air" does not work..... the air doesnt just travel to the easiest place to get out from under the hood. Air flows like a stampede, if you create a vortex, it grabs more air and moves it.

The easiest way for me to demonstrate this to you would be if you own an air gun. The picture below of an air gun has 2 holes in it. If you cover those holes with your fingers you will notice that the amount of air that gun puts out is nearly cut in half... then when you remove your fingers from the holes the gun will start blowing at nearly double the rate that it does with them covered. The vortex created inside the barrel is so strong that it sucks air into the holes. Ultimately the goal achieved is that a larger volume of air is moved. Works the same way in a car's hood. If you create a vortex...... whether it be up down or sideways, that vortex will pull the air out of the engine compartment. This is the same reason that intakes are supplied air or moved outside of the engine compartment. "allowing air to escape" disrupts the vortex.

Honda engineers are smarter than you. Everything they do is there for a reason. Under the hood of that CVCC illustrates everything i just tried to explain.