I recently ran some experiments changing timing in the idle zone. 13 degrees always struck me as late given that a stock distributor averages 30-40deg during cruise loads.

I found that 19 degrees BTDC saw a measurable decrease in MAP and measurably reduced injector PW. Idle feels less lumpy, and transitioning from cruise back to idle shows less tendency to rev hang. Idle advance correction seems to have more affect at this higher range.

Just wondering if anyone with ignition control + idle advance correction has tried something similar?