ORIGINAL: GidyupGo

I didn't mean it would add 100 HP. But there is air flowing over the hood and it is moving so it will help.

ORIGINAL: breathegood

Until the cfm flowingthrough the hood scoop is equal to or greater than the cfm that your engine is pumping, your HP increase will be exactly zero, zip, zilch. Say the vacuum pump that is your engine pulls 10,000cfm (just an example, but not an unreasonable number given the size of the engine)through the intake.You must be traveling fast enough to flow 10,000+1 cfm through your saucepan before you will seeANY HP increase. Now up to that point you will be increasing the volumetric effiency of the pump. The engine doesn't have to workas hardso your gas mileage and throttle responsemight improve (for some it's worth it, kind of spendy for my taste), but that's it, no extra ponies because there is no extra air. You cannotdefy thethe laws of physics. How fast do you need to go to flow 10,000cfm through a saucepan that has an opening area of 0.2sq.ft. (approx 6 inches in diameter)? Well at 1mph you will flow 17.6cfm, at 60mph just better than 1050cfm.....@ 568mph you will be just breaking even at 10,000cfm and then you start making real HP!!! Who needs a privatejet when you have that car!!!! Keep in mind, this assumes that the intake is in an area of high pressure and will actually capture that much air.A typical hood scoop will not. It's a nice thought though.