Timing after Speed Density

[NewV]

Go back to the fire triangle/internal combustion basics...with respect to advancing/retarding the timing of the spark plug firing you are literally changing the whole burn event. The speed density tune you have been working on is based on the Air prediction table or VE; this is intrinsicly related to the spark tables that are based on airflow grams per cyliner, gm.dyncylair_dma

Fuel, Air, Spark they are all interacting with each other.

I am sure somebody else could give you a more statesman like, learned response. This is the best I can do right before bedtime.

Ok I get the whole timing of the spark but thought the VE table after the speed density tune simply gave me an educated view of airflow capabilities. I guess I thought the computer really determined how much fuel to give it compared to airflow and would compensate for the added timing. However I think I see your point as I am determining VE based on measurement after the fire during the exhaust cycle.

I need to do some more VE logging this weekend and check it out.

Thanks guys.

[Big Kahuna]

DO something simple like dropping the timing at idle speeds. You'll find the AFR richens up.