Saturday night drift again

At noon was well prepared with all my r/c models, well tuned KYOSHO MINI-Z and NRX-18 already upgraded with new 370 racing motor with custom 7.2V 2700mah enough torque power to drift along the circuit. At local hobby shop people swarming around to get parts and stuff for tonight event. By night at 10.45pm everyone at the drift circuit. I also met our local forumer who also seem to be in the same interest on 1/18 scale r/c tag along for the run. My first run was sprint duel again another brushless NRX-18 player but i'm using my 1/28 Kyosho Mini-z againts him. Was fast and extreme drag duelling especially i'm up again larger size brushless. After 1 hour 30min run time he won't by 1 second difference ahead of me. After drain sets of 4.8V 1000mah battery on my mini-z i pulled out my NRX-18 1/18 to join the other drifter on the track. With new 370 motor the car was powerfull enough to pull a huge side slide drifting partially around the circuit but dampens by soft compund tyre and short lived 15min battery. So i pulled another custom 7.2V 2700mah battery power and slot into my 1/18. I pulled the trigger 100% throttle thecar stutter and halt, ESC beakons an emergency overheat sound. I tried several attempts but still the ESC beacons emergency sound which inform me that big troubles is coming to wreck my day. Unable to troubleshoot the problem at night so i decided to halt for the day and went home with other at 12.38am at midnight. At home i made several test and found out i've fried a speed controller chip which suppose to handle more current. After long toughts i decided to get new ESC parts and motor to cope with the demanding problem.