Dave,
These vortex spiral systems have little effect, if none at all. They claim an increase in HP, Perhaps in one test engine. Usually the 1 hour commercials claim many things. Some claims may be correct, but they may not be for your engine. Be an educated consumer. The only way you will get more horsepower, is by changing the computer's settings, or by changing-out the mechanical parts of your engine.
Most engines today are maxed-out, to get maximum HP. When you try to tweak these things, you will void the warranty, or damage the engine, when you push it to hard. Most engines that are tweaked to get max HP out of them, are usually short lived, unless you make major changes to the engine.
GMdude