Razor kart upgrader

So far the attached is what I've got, I've just overvolted the stuff. Looking for more!

The dune buggy looks like it'll take an brushless my1020 just fine

the drifter, not so much.

Seems like an "escalation of force" problem. I mean sure you can upgrade the motor, but then you should probably upgrade the axles and then you probably don't want that much stress on the wheels/tires so upgrade that too, then the brakes won't stop you fast enough, then the ball joints ect ect...