So I bought a LRP Sphere and Neo-One (3 star) combo, intalled it in my drifter, and tried it out. It worked fine, until about five, or less, minutes into the fun, the car began to slow down. It messed up in a way that it would reach a certain speed, a very slow one, too slow for even slight drifts, and then would slowly lower that top speed and all speed entirely. I need some help. I think the motor may be defective. Any help appreciated.

Have you checked to see if the battery is fully charged,andother thing to check is that the tamia plugs are making contact, had that problem with mine so upgraded to gold bullet connectors.I personally find the 3 star brushless way to powerful for drifting so i limit it to 24000Rpm, and seems to work ok.
Hope this helps

I would say you just thermaled the ESC by installing it in a drift car. It probably stayed at full throttle the whole time and got too hot.

A good 27t stock motor is all you really need for drifting. That motor combo is kinda overkill IMO. I am thinking about trying the Novak SS 4300 though.

You right on the brushlesss being overkill for rc drifting, have now replaced it with a 20 single