I read an interesting post in the GM section about Optimum being nothing more than an urgency table for main spark:
https://forum.hptuners.com/showthrea...rk-tables-how-
Basically the higher the value in Optimum, relative to Base, the greater the urgency it pushes the value in Base. If Base was 5 and Opt was 5 you have 0 urgency to drive to Base. If Base is 5 but Opt is 10, then you have a "5" level of urgency to drive to Base. I don't know what urgency is because if it's not the base of 5 at that moment, then wth is it?
I kinda doubt ours is the same, but that's why I'm asking. Originally I thought it was like it sounds, Optimum is the perfect timing if you had the octane to pull it off, and Base was minimum timing. Clearly that is not the case based on what I see, since my timing is often less than Base, which I can't explain at all. Not ping or Cat or tip-in retard, just retarded and I don't know why.
So what is the Optimum Spark? Eg; at 3k rpm and max load my oem Base is 5.25 and Optimum is 12.75. What does that really mean? What happens if either were changed?
Eg;
Base 10.5 and Opt 12.75
Base 5.25 and Opt 18.0
Or both raised to 10.5 & 18.0?