Found a nice white paper that documents the processes behind generating and testing a compressor map. I know a lot of people just think they are simple little tools for turbo sizing but it goes much further than that. Considering the average cost to generate ONE map is around 20,000 dollars, also consider the various housing combinations that get tested on one wheel you can see the costs involved. You can see why having this information available is quite valuable in more than one way.

http://digitalcommons.calpoly.edu/cg...ontext=aerospg

and another nice article from MotoIQ

http://www.motoiq.com/magazine_artic...bine-maps.aspx