So both my sons were running the Sanwa MX6 and had no issues unless there were 6 or 7 other guys running and then they would both randomly lose signal to the reciever and control of their cars. My oldest sons car actually lost signal on the straightaway at our local track and launched into the pits. My oldest switched to flysky noble and I bought my youngest son a sanwa mt4s and I run the new sanwa mt5 all with no issues.