Hi Wynn,
I was going to say, add some ether......but ....I'll resist the temptation
I reckon that you simply hit the highest rpm that the Turnigy will run at for that particular setup. You could try disabling the governor on the ESC and then wind up the pot on the timer to see where the max rpm is. If you have an R/C system then try that to see what the motor can do.
I've never used any of the CC ESC's, but I know that many of them require you to set the upper and lower throttle range. If you get higher rpm on the R/C system, then maybe the ICE 50 has been set to a higher pulse width than your timer is putting out. For example, if the ICE has been set for a high end throttle of 2.2 ms, and your timer gives you a max of 2.0 then you just not reaching the maximum throttle. Let us know what you find.
Keith R