Okay...getting into these maps I see that load is used a ton for some of the axis along with rpm.

I understand that load is calculated based on MAF size, air temp, and BARO.

When I pull up the high det-low oct map for just an example I see rpm and load, and afr numbers in the table.

My first question is how can the load be over 100% I am assuming it is in percentage because of the turbo?

Do the load numbers stay the same as some sort of reference point for every map much like rpm? So you log...find where you have the point where the load and rpm intersect that you have an issue and go into the rom and tweak that number?

I have the engine management book, I have read merlin's guide, I have read the Cobb manual...and just starting to wade into this.

Getting a wideband, have a way to data log, and getting ready to fine tune.

 

instead of load, call it 'volumetric efficiency'. its the relationship of the mass of air entering the engine and the egnine's volume at atmospheric density.

Our engines displace 2L. 100% load means that we have enough air at 0psi (relative) to fill that 2L. 200% load means we have twice as much air thanks to the turbo compressing it for us.

http://en.wikipedia.org/wiki/Volumetric_efficiency

 

Thinking of it like VE is a good way to grasp it, but in reality it is just a number in a system of numbers used to represent something in the physical world. Without the system of calculations most of the numbers (that aren't inputs) mean nothing. It is not completely arbitrary (as you seem to know), but it is simply the way someone decided to represent the output of a group of inputs.