I'm backin' Rob on this, as he is quite correct in what he says, even though others seem to misinterpret what he has actually said.
This device is probably snakeoil, because the gains it can give are only available after major current drain, which itself will cause the alternator to work overtime to keep up, and how many horsepower will that sap?? I'm willing to bet more than the fan can deliver.
[Fan blade pitch needs to be set to an optimum efficient value for the rotational speed of normal operation. Outside this range they can be very inefficient]
As a fan of superchargers, I know that driving them to the 100,000 rpm they need to get up to in order to deliver operating pressure will use up a possible 40 hp, depending on the device and efficiency.
In principle, ram air can be used to add horsepower. Kawasaki bikes such as the ZX9 gain horsepower at very high speed from ram air effect. Speeds would be pretty high, over 120-130, and the added horsepower is I think about 5 extra on a 120hp bike. However, this energy is "free", or at least taken back from the wind pressure the bike creates at this speed, it does not have to be produced electrically or mechanically by the engine.
Joe
