i got my own

i got it there pretty cool but to slow my bit (wich is fake that i got for 15$) is now broke it just spin circales any way i buildt a trach and when i go around a conner it slow down alot i mean a lot so shound i get the bigger motor does it really do any thing someone said the NOS motor does nothing so should i get it

i am only 12 and have a short budet and the zip zap is really my moms but i have the money right now and radio shack is two block away so shoulg i get it or not.