Sea Level vs Altitude Tuning

[Power Hungry]

FN1204 = Start of Injection Delay. The one that looks like it has a valley running through the middle of it. FN1104 is a similarly shaped fuel pulsewidth multiplier table.

As for Ford's reasoning behind the maps, I don't have a reasonable explanation. You do have to consider that their tuning equipment and software was much less advanced than what we have today. When you consider where we are at with tuning nowadays compared to 6 years ago when 7.3L production was halted, the jumpiness of the mapping makes a little more sense, or is at least excusable due to limited development tools. Also, I'm not sure if they were doing steady-state tuning, loaded tuning, or what, but I'm fairly sure that they would plot along certain points in the maps and the fill in the blanks. That's my guess anyway...