an m445 or an x 642 are pulling upwards of 80 amps, which an AQ motor can handle in 5 second burst. Not really sure how you guys are running 4 + min with an m445, I pull over 2500 mah after a 2 min race, 2 more min and my batteries would be pissed and motor wires would start de soldering. Im in the 45-48 mph range. certainly not 54. I suppose it could be done but I put a lot of importance on actually finishing the race so maybe I'm not running as loose as some of you guys .