Sea Level vs Altitude Tuning

[soutthpaw]

Ok I think I am gonna leave all the WHY questions to you now Cody.. then at some point I am going to put them all in one thread and get Jack to make them a sticky... Excellent explanation as usual. I give it

As for my previous post, It looks like the Timing is an actual setting and not a modifier? that's why I thought it should be different for each different map... Here is the Stock sea level vs altitude map

The part that is Highlighted in yellow I thought was interesting.. Reason being is that we know the burn(Combustion) time is a constant at the selected altitude.. so if the engine is turning faster you should need to start the Burn earlier given the same amount of fuel. Right?
so why does the stock setting retard the timing so much in the higher RPM's in that sea level map.. also it seems like there is a mid RPM range that requires retarding the timing a bit that I am wondering the reasoning behind it (is there another modifier somewhere in the parameters that justifies the retarding of the timing that I am missing)