I know it was pricey but based on your report I have to say I do not think this really does a whole lot for this particular engine setup. I think the stock setup and the stock s65 is more than adequate to run a track in 90 degree weather all day let alone 60-80. The brakes will be the limiting factor for most people or tires for that matter.
To spend 2k and not even show a drop in temp on the guage clinches it that this is just flushin dough. But I am sure it gives a nice placebo effect knowings its in there.