the blower on the car produces an insane amount of heat for the boost you're seeing. KR is the PCM pulling timing because it senses detonation. given that the car is on a smaller blower pulley than stock and not properly tuned or enough supporting parts you could very well be seeing a loss of 4-7* of timing. this would decrease your timing enough to jack up cylinder temps a large amount, thus the car heating up so rapidly.
however, you should not be seeing it increase at a heavily noticeable rate unless you are doing a high speed run as mentioned above. the radiator being gunked up means the rest of the coolant passages are too. it's time for a flush and refill.
