I knew there was a chance that my 360W/12VDC power supply wasn't capable of giving the two brushless motors the juice they needed to hit maximum RPM; in order to quantify this, I hooked up a current shunt and ran some full-throttle tests:

That's a 50 amp full scale 75 mV shunt, so 0.054VDC = 36 amps. Not bad for a supply that should only hit 30 amps, but it meant that I might be current-limited due to my power supply choice. Time to break out the LiPo batteries that arrived earlier today:

I grabbed a bag of connectors too, so it was fairly simple to splice 'em in to the existing test rig (one per motor). 

Charged! 

BAMF. 2kg+ thrust, more than enough. Loud and lots more vibration than I saw at 1450g, but the new motor frame design should be quite a bit stronger than the test rig. 

Big caveat here: these batteries are 4S units, so they're putting out nearly 15vdc. That means they can turn the motor faster than the 12vdc power supply can, at least theoretically. However, I used the power supply's built-in calibration pot to jack the power supply up to 14vdc and I still got 1450g thrust, so it's hard to say what the limiting factor is. One thing I do know: I need that GE power converter. It'll hit 50 amps at 12 volts and should tell me for sure whether or not my prop/motor combo is adequate.