K+N filters will destroy the mass air meter. Look for a air filter by Macs. Wet filters are evil, I end up taking them out of customers cars after they foul the meter. I am a Ford tech btw.
I can see the "tornado" style effect being useful for some engines, but not fuel injection. What exaclty are they trying to accomplish? With air and fuel as in a carburator, I can see them trying to swirl, but with air alone, I dont see what their trying to mix.
Stick with a good CAI kit or just a Macs filter and call it good. You will make much more power with an aftermarket catted h or X pipe,, save your pennies!
here is the mac cai kit:
they sell for about $175