ZPB, if cooler running is your goal, you don't need to go to voltage extremes. I, like you, have envisioned a higher voltage system that would draw fewer amps and run cooler. I thought that I could reach a point with a Feigao motor that would run cool. I've progressed downward from the 7XL, to the 8XL, and now to the 9XL. I tried just going slower and adding voltage. What I have discovered is that the cheapo Feigao motors are going to run hot no matter what, in any setup that delivers any sort of respectable performance.

I've read a few posts of guys talking about their 9XL or 10XL setups running ice cold. After my experimentation and experiences, I think that they are either full of it, or they just aren't pushing their setup.

I've talked with Mike about the subject on the phone and the conversation was a revelation to me. He informed me that just going with a more efficient motor will significantly cut the running temp of the motor and you can still run on 4S.

If you think about it, the Feigao is only about 80% efficient, at best. The Neu motors are about 90% efficient. I'd imagine that most would say that there is only a 10% difference in efficiency and that it couldn't make that much of a difference. Well, there is only a 10% difference in efficiency, but that's not the way to look at it. If you really think about it, the Neu is only wasting half as much energy as heat as the Feigao motor is. This means that the Neu motor will run much cooler. If you want cooler running, then go with a more efficient motor. No need to kill yourself running higher voltage just to run cooler.

I, personally, have found 4S to be the best way to go for racing and gets the job done for bashing. Higher voltage is good for going fast. If fast is what you want, then go for it; but going to 6S with a Feigao isn't going to get you a cool running setup. I don't think so anyway. I haven't seen it.