Thanks for the info guys. It does help to understand the mechanics of it. I had reset the ESC to factory defaults. Then I incrementally lowered the timing to "0". That didn't help. I hooked up the motor in my car(no load) to an ESC in my sons other car and the cogging almost went away. The more I read up on this, the more I find other people having the same issue with this ESC/Motor combo. The majority replace the ESC and its fine. I'll try throwing a smaller pinion in there to see if that helps. If not, on to looking for a better ESC.