I assume you mean the ones that "swirl" the intake air.
Word is they make a "supercharger" like whine that some find annoying, while others find cool.
I would consider putting one on, but I have not seen anything that says they really work. The idea is that the increased turbulance going into the intake manifold and on into the combustion chambers will help the air mix with the injected gas and give (insert advertised horsepower gain here). Problem is, the intake air goes through quite a "tortured path" (real engineering term here), and is pretty turbulant by the time it enters the combustion chamber (coupla right turns, over valves, etc.). Also, if we put one of these things on, are we NOT to go ahead a port & polish our intake manifolds (like the pros do) to smooth out the intake path and get some real horsepower gains????
Now, if the Exby had Throttle body injection, I would very much believe this claim, as the mixing is at the point of the "swirling".
Now, enough of my over-thinking on this subject. Anybody actually have one of these things on, and did it make a difference?
