[piratius]

Coming to chris's defense (prototype240)

The funnel analogy doesn't work because aside from gravity there's no force applied to the oil.

Air has mass, agreed? Even though in normal circumstances we don't think about it. It has mass, else Mass-airflow systems wouldn't work.

Because of this, as the car passes through the air, at increasing velocities, the force of the mass of stationary air against the front of the car is what we know as "wind resistance" or "airflow resistance". It's a property of any system that involves fluid/air dynamics.

Now. The hand-out-the-window analogy is a good example of how much force the mass of air has on a moving object. If you held a cup out the window (assuming it had a pressure gauge attachment and logged pressure vs. car speed), and started at a stop you'd see no pressure. As you went 5 miles an hour, it'd probably still be not-noticable. As speed increased, you'd realize it was harder and harder to keep the cup stationary. Why? Because the mass of air pushing on your hand is causing...pressure against it!.

The faster you go, the more pressure you'd see inside the cup. Repeat the experiment with a small hole in the cup. At low speeds, and even medium-low speeds you'd see no pressure, as enough air could escape to keep it atmospheric. Eventually though, you would pressurize the cup. That's almost exactly how an engine would work.

Case in point - does anyone remember that awesome writeup where they took the 17 second car and made it run 14's for...i think it was free? They cut all these body panels off, roof, fenders, bodykit, put lightweight rims on (doughnuts)...

They ran it each time they cut off a body panel or modded it. Then, the pulled the airbox (with filter off) so that it was up in the airstream, and duct-taped it in place. Unless I'm remembering completely wrong, they found a .1 or .2 difference in e/t. .2 seconds is more than 4-5 horsepower, more up top where the car needed it. If I can dig up the article, I'll post it.

~Brad