Archives: air/fuel ratio

Optimum Air/fuel ratio

Is there an optimal air/fuel ratio for drag racing engines? While air/fuel ratio is important for fuel system management, there is no one optimum air/fuel ratio.  These depend on engine type, fuel type, and engine modifications.  Below are examples of some optimum air/fuel ratios for specific drag racing engine examples: engine induction fuel air/fuel ratio […]

Idle & Low End Air/Fuel Ratio Tuning Tool, Flared/Radiused Jet Orientation

We are now developing techniques using our jetting calculator to set up idle air to fuel ratio for really good MFI racing engine tuning.  Idle settings in many MFI racing engines are key to superior performance from engine temperature and off idle response. That is done by adjusting the combination of idle vacuum (throttle blade […]

Fuel Injection Setup & Tuning

… by Experience & Gut Feel Throughout the racing community, experience and gut feel are the most common methods for the selection of nozzle and jet size numbers for setup and tuning of mechanical fuel injection. It is a form of iteration or ‘connecting the dots’. Given enough time and expense, experience from good and […]

Uniform Standard of Units

Throughout our publications, air intake and fuel delivery values are converted to a ‘uniform standard of units’. That is “pounds per revolution”. The tuning demands for weight of air and weight of fuel become easy to understand, record, and analyze with that numerical value. And easy to change in fine tuning increments with this simple […]

E85 as a Racing Fuel

E85 is examined as a racing fuel.  E85 is a combination of ethanol and low octane gasoline.  Some racers report more power from E85 than from methanol.  On the other hand, when the Indy Car League converted from methanol to straight ethanol, dynamometer tests revealed a reduction in power after the conversion.