I saw a infomerical at like 5am once (insomnia, parents out of town, bigscreen downstairs...yeah, I was up at 5am) about something almost exactly like it, but it had a different name. the IDEA behind it sounds about right, from a HS physics student's point of view.
What it supposedly does is SPIN the air that comes in, which in turn "spins" the fuel intake (by spin I mean...kinna like a tornado.) The idea being if the air intake and the fuel intake are x inches away from each other, they don't really mix that well when shooting into the cylinders straight. by spinning the air intake it's causing the fuel and air to mix better. actual hp or gas millage gains will range...incredibly. I'd be interested in seeing what happens to a tC. if anyone has the money to blow, do it and give us feedback!
biggest gimmick ever in the history of gimmics. ANY object that is impeding the path of air from the filter to the intake manifold without creating a REAL boost in atmospheric pressure (PSI) is causing a loss of horsepower without questions. Do a search www.google.com for reviews on the product and you will see that it is a complete wast of cash.