Without the U.F.O., the air hits the forward wall of the slide cavity creating a rolling air turbulence which forces the poorly atomized fuel droplets to the lower portion of the carb bore resulting in poor fuel atomization and poor performance.
With the aerodynamic U.F.O. filling the slide cavity, the rolling air turbulence is eliminated. The higher velocity air flow pulls the fuel further up the needle and higher in the carburetor bore resulting in superior fuel atomization. This means more HP, quicker throttle response, improved fuel economy and a cooler running engine.