Could you elaborate on the advantages (carb tuning related) of the A/F sensor over BSFC?
BSFC stands for Brake Specific Fuel Consumption and is reported in pounds of fuel consumed per hour, per HP. Very efficient engines at full power at their torque and HP peak typically run about .40 to .45. This means the engine requires .40 lbs/hr of fuel flow for every HP it makes. If it was making 1000 HP, the fuel flow required would be 400 lb/hr (or approximately 1 gallon of fuel/minute, GPM). BSFC is a measure of how well the engine is converting fuel into HP, NOT how rich the engine is running. For example, if you retard the spark 20 deg, the BSFC goes higher (say from .40 to .50), to many people indicating the engine is richer. The engine is NOT richer, just less efficient at converting fuel into HP. A major problem with fuel flow measurements (and therefore BSFC measurements) is fuel flow meters have a limited operating range. At the low end they get inaccurate or don’t read at all. At the high end, they get restrictive, changing the fuel pressure significantly in the fuel line
