To convert 2bbl CFM to 4bbl CFM , divide the 2bbl rated CFM by 1.41. To convert 4bbl CFM to 2bbl CFM,multipy 4bbl CFM by 1.41. This formula is used by carb tuners,there are variables,only is accurate for the pressure drops 4 on the floor listed, but it's a good quesstimate.
