There is also something called the Tornado that goes into the intake hose that causes the air to swirl around as it goes into the intake manifold. It's a small spiral piece of sheet metal inside of a tube that they charge about $60 or $70. The design actually has some basis behind it. There is a very similar spiral strip of metal inside of every gas powered hot water tank that goes into the chimney. It helps divert the exhaust upward, and controls the air flow so that there is no excess draft coming out of the chimney that could blow out the pilot light. As for the automotive use of it, I don't know how it will increase air flow going into the manifold. Maybe they assume that it will act like a heat sink, and cool down the air going into the manifold to increase performance. A turbo intercooler/heat exchanger would be more efficient in this application.