Most of the chart is self explanatory but there are a few interesting and (to me) mystifying points.  Note the L. Rad Air Out temperature (air temp after passing through rad).  According to Paul L., the optimum for this parameter is 10 - 20 deg F. above ambient OAT.  I wanted a lot more than that to minimize the number of CFM required and as you can see, mine is running as much as 127 deg F above OAT which is even more than I figured on. 

It’s possible that Paul was referring to the coolant rather than the air.  Somewhere around 20 may be optimum for the coolant; and something more like 50 may be optimum for air side.  Your 127 F is similar to what I’m seeing on my wing-root without a scoop; clearly indicative of low air flow.  It makes the average rejection temp more than 60F over the OAT; not very effective. I don’t recall – are your rads in series or parallel? Do you have coolant in/out for the left rad only? 

Very useful plot.  Nice job.

Al