I still don't understand how, in a MPFI fuel injected engine, the air can still be spinning beyond the throttle body. The vortex that it creates would be in the very center of the air tube, and the opening when the throttle is pressed is at the very outside of the throttle opening. Seems to me that the throttle body would cancel out the effects of the vortex.
Now a TBI or carbed engine would be a different story, since the air and fuel are mixed far before entering the cylinders.