It would really help if you gave us as much info about your car as possible.
What kind of speed controller are you using, brand and model.
What reciever and transmitter are you using, brand.
TT-01/Hitec MG/SP LPF V1.1/Trinity 7.5
Losi Type-R/JR Z8800S/SP Cirtix Stock/Novak 25.5
Exotek F1R/Savox 1251/Tekin RS/21.5
"ELECTRIFIED TO THE HILT"