Originally Posted by Ultrasonic2 (muffy)
it would go a lot higher than that but the speed controller would get VERY hot and stop. in the pic i have a bag of ice on it. i was gonna put some heat sinks on it and stuff but i never got round it it . the pump was a good heater too. see heat testing
Looks like you were using a very small Astro ESC... since you were running liquid, you should have gotten a liquid cooled ESC. (Yes ESC's exist with liquid cooling) We run them on RC boats drawing hundreds of watts, motors over 1HP (~750W) are common. (Schultze makes some of the best)
Also I wonder if it would have been possible to drive the impeller with a new motor? Run a small Hacker/equivalent brushless motor in there at 45+k rpm.
Regardless that's pretty cool...