START OF INJECTION TIMING

A method for controlling fuel injection timing into a cylinder of an internal combustion engine having an internal control system based on ignition delay correlation wherein intake manifold pressure and oxygen concentration values are compared to steady state values of manifold pressure and oxygen concentration of a particular indicated torque set-point and engine speed. Comparing intake manifold pressure and oxygen concentration to steady state reference values further comprises experimentally determining exponential factors for intake manifold pressure factor and oxygen concentration factors. A multiplier for intake manifold pressure and oxygen concentration is determined taking into consideration the exponential factors for manifold pressure and oxygen concentration. An equation for correlation ignition delay is used to determine optional SOI timing.