im still playing around with that, i really don't think there is one definitive answer to that question. there are way too many variables to have THE answer. Temperature, altitude, pressure, compression, cylinder pressure, fuel, and the list goes on.

 

finally when I thought I understood EFI a little bit i see this thread haha. Wow having trouble understanding that. I run about 30* timing with 2600 pulse width I think at higher RPMs in my race tune.

 

my thought is that you would want the injection event to begin as soon as possible without causing a detonation and to end as close to TDC as possible to insure the most even spread of fuel throughout the cylinder?!?!