Yup I have tested one. hness or anything else engine related. I haven't actually noticed it.
In theory it should work as organising the airflow into a swirling vortex should allow more volume of air for a given area to get through. But as there is also a turbo downstream of it compressing a volume of air it might be a neglegable change.
I'm afraid the theory you assume MUST be incorrect. Logic says so, and the proof is that the people who flog these things have never submitted to independent testing. I can remember similar things being marketed way back in the 1960s, and my father warned me off them. He said he had been offered something just the same for his first car, a Bullnose Morris Cowley in 1927!
The reason for this being a snake oil product is simple enough. Think it through logically. To get the AIR into the engine, the air must MOVE. It must move from the outside all the way through tubes, filters, pipes, intercoolers, bends, manifolds, and past valves into the cylinders, which is the only place the air does any good.
Fact - more air is good. Hence the turbo to ram double the air in, and free-flow filters. Get the idea .... FREE FLOW .... INWARDS .... good.
Fact - if the air MOVES FASTER then more air will reach the cylinders in any given time.
Fact - EVERY obstruction to airflow MUST slow down the VELOCITY of the air-stream going inwards.
FACT - after every obstruction no matter how slight, air pressure and velocity go DOWN. That's not a good plan. We want the incoming air velocity and pressure to stay UP so that the greatest possible MASS of air reaches our working cylinders.
FACT - the cyclone thing is a fixed series of radial vanes partially obstructing the incoming air flow, and inducing turbulence.
FACT - diesels induce their own "swirl" IN the cylinders as the air passes the inlet valve(s) Any turbulence before there MUST be bad for the reasons stated above.
All things considered ..... bad idea unless you happen to be the guy taking the money from the poor deluded souls you told those lies to.
However, in some really badly designed gasoline engines with ancient carburettors it MIGHT be the case that inducing swirling just below the carburettor could improve the atomisation and distribution of the petrol in the air stream, and that might make such an engine work a tad smoother. It might on the other hand make the air flow and fuel distribution a whole lot WORSE. But, as someone pointed out, it isn't a patented idea (they have to show it works to patent it) and as it would cost car makers about 20 pence a car to fit them, they certainly would if they did any good.
But they don't, so buy and fit an EGR plate instead. That does work, for a fiver.
CharlesY
