Oh, BS. It was a gimmick that someone made a bunch of money on, thanks to advertising and a lot of people with no common sense.
Sorry. But I’m not buying into any of this “spinning air” in the induction system as having any effect on a MPG or performance increase.
So what if you get the air spinning prior to (up to 2’ away) the throttle body?
Do I think it’s still spinning when it gets there? No.
Do I think it keeps spinning after going through the throttle body? No.
Is the air flowing at the same rate and in the same direction when it gets to the injector and intake valve, regardless of what you do to it upstream? Yes.
So what’s the point in making it spin prior to that point?
The only effect I can see in spinning the air that far up the induction system is to separate the dust out of it that the filter may not have caught. If that’s the case, you need a better filter.
Sure, a turbocharger may be more efficient if the air is moving into the turbine at a specific angle. But is it that critical? No. If it was, the manufacturers would have built the inlet to the turbine (cold side) with inlet guide vanes. Ever seen one like that? I doubt it. I know I haven’t.
And with the flow rate ever changing, what’s the point in that anyway? They would have to variable inlet vanes, and that’s not going to happen any time soon (if ever).
With all cylinders pulling air. There’s no way that air is going to maintain a circular flow through a (often corrugated) tube for any length, much less around the bends that most systems have today. And if it did. So what? It wont be after it hits the throttle body.
Go buy one of these devices. Better yet, just make one out of a piece of poster board. Run by Home Depot and pick up a 24” piece of clear tubing/pipe. Mount it on the end of the pipe and your vacuum to the other. Turn it on and blow some smoke into it. Note what you see the smoke/air doing (flow) a foot from the gadget. Now remove the thing and repeat. Note any difference in flow pattern a foot away? No.
How do I know this? I’ve seen it done before, more than once.
Air movement (like any other fluid movement) wants to take the path of least resistance. And that happens to be STRAIGHT to (or away from) whatever is making it move.
The only thing (air related) that helps increase performance is the amount of said air getting into the cylinders. That’s why we see cars running around with turbochargers pumping more air in, and inner-coolers cooling the air to increase its density. It’s all about volume. Not how we can get it spinning upstream.
