Excellent write up, thank you for taking the time to do it.
I am curious as to why your rear brake temps were so high, its almost like the spongy brake pedal was your fronts not working like they should which shifted load to the rears causing the higher rear brake temps on your car. Did you happen to notice if the other comparison cars had better cooling to their rear brakes?
Any braking experts on here care to comment on this?
My R33
G4 brakes (356mm disk, G4 'street' pads): 130 degrees
Standard rear brakes (Nissan OEM pad) 280 degrees
Another R33
F40 Brembo brakes (340mm disk, Ferrodo 2500 or 3000 pads): 300 degrees
Standard rear brakes (pad unknown): 150 degrees