Here is the plot for the data provided for the T770. Notice the linear drop in pressure from 0 - 31.2 gpm? The pressure decrease over this range is only 800 psi. Clearly this is not exponential as you declared earlier. Would you like me to plot this on a log graph?
I don't have the schematic for the T770 but apparently from the brochure it runs gear pumps. A gear pump is a fixed displacement pump. The aux flow apparently has two configurations: variable flow and max flow. Which mode was the aux circuit running in? What was the rpms that the flow was taken at?
Get me the hydraulic schematics and I'll tell you what is going on.