distantpulse did you bleed the system after the sep. kit? sounds like an airblock.
i have dj's supercooler and i love it. i run a bit higher engine temps in the summer due to the cooler being in front of the rad but nothing excessive.
i dont have datalog capabilities yet but before the supercooler s/c shutdown was a daily thing in the heat. since the install with a cm30 and separation i havent had a single shutdown whether racing or sitting in 100* heat car just runs great