Thanks for the replies. My rationale:
The project has progressed well past first thoughts, goals. Need to understand the "why" and if there are benefits to additional feature/function/parameter. An FI system is complicated, but extremely interesting.
VE (fuel) table, understand, spark (ignition timing) table - generic ignition timing - understand the balance, AFR table - bring the VE (fuel) table back to steady throttle.
Engine operating well, coil dwell good, fuel injectors working well, fuel under control, voltage corrections calibrated, O2 sensor calibrated for "simple" or "PID". Why change settings?
Time to fine tune the spark (ignition timing) table for advance. Timing advance at this stage is to compensate for the fuel ignition delay when an ignition event is required, much like a fuel injector. Takes time to bring the fuel charge to max burn so that the maximum combustion pulse occurs at the appropriate ATDC timing of approximately 10 or so degrees resulting in maximum power and fuel economy.
Fuel Ignition Delay.jpg (76.41 KiB) Viewed 706 times
There are quite a few extra features/functions/parameters that one can look into depending on the engine tune parameters. Sequential fuel and ignition (my engine), ICFT - individual cylinder fuel control - how this can be used regarding closed loop O2 sensor operation, barometric sensor addition, idle advance setting, IAT retard, cold advance, and others.
My project allows me to understand what I read on this forum and on-line. Hope this answers your queries. I'm an inquisitive sort.
Merry Christmas and a Happy New Year to all.
Ernest