I'm assuming the Rally purchased was one that came with the 12T Titan motor in it, and the 5700Kv was an upgrade. Quite a big jump in motors I must say, if that's the case. I could never get the full potential out of my 5700Kv motor unless I was running on smoother surfaces and traction was there. Like seedygreenute said...It is fun trying in an off-road situation though.

If your tires are just ballooning when your RC is "diffing out" , then you should look into thicker diff fluids as well.