I don't have any knowledge of Drift Cars or RC cars in general. This is the aircraft forum. If you want help with cars you would be better served in the car forum.
http://www.rcuniverse.com/forum/rc-c...anks-more-225/



First question, why do you want to switch it? I presume it defaults to one or the other. What is the default?

Is it not working on the default frequency?

All I can offer is, when all else fails, read the instructions as that would be my only path. The instructions don't seem to be available on-line.

Why do you want to drive on 40 mhz as opposed to 27 MHz? In the USA the valid frequencies for cars would be 27 MHz, 49 MHz, 75 MHz and 2.4 GHz. 40 MHz would not be legal in the USA.