The best "version" of what Don is describing is probably the 3W CF intake extension that goes above the carburetor, and has a vent line that attaches to the front of the pressure diaphragm. This system basically balances the pressure at the carburetors throat with that at the atmospheric reference port on the fuel pressure regulator diaphragm. I've always felt that the "balance" line going into the fuselage does not properly reference the pressure drops and changes associated with the air entering the carburetors throat and venturi. Add to that the length of the balance line/tube, and you now get a less responsive diaphragm since the long, but small diameter tube tends to damp the pressure changes that a shorter tube would allow, effectively making the diaphragm too unresponsive to the pressure and flow changes the carburetor is experiencing.

Personally, I'd rather see a totally enclosed carburetor housing that prevents pressure fluctuations and high velocity air from striking the carburetor in any way, such as a large air cleaner assembly on a race car. This, plus making sure that the carburetor, reed cage, and gaskets, are totally sealed, would go a long way toward smoothing out our engines no matter what flight attitude.

I'd also like to see a TRUE FI system developed. . but I really don't think anyone is going to invest a couple of years and $25-50K to develop a system like that which will not sell very well and be expensive if it does sell. I have parts for such a system laying all around. . injectors, low and hi-pressure pumps, a couple of controllers, but its all focused toward automotive usage and way more than I'd ever need for a 150cc "Fuelie" system . .Oh well. . back to the drawing board.