[lincpimp]

Motor ratings by the mfg are not really a good way to determine amp draw. Most of them are done with a certain sized prop with a specific voltage. A motor in a car will draw more amps with lower gearing and more with higher gearing. I would say that on 5s lipo you want an esc that is rated for 80amps. I have a few quark 65 esc and have used them in my 2wd emaxx, which is not light, but does not have the ability to load a motor and esc like a 4wd vehicle can. You battery choice may be a bit small too, 44 amps at 5s lipo is 814watts and figure the motor may be 90% effecient at most, so thats 730 watts. That will most likely not be enough power to get to 45+ mph. I would gear down so that speed is closer to 40 or slightly under. That will take some load off the battery. The buggy should be quite light with that pack. It is always good to have some margin when choosing an esc and battery. Most 4s setups can draw 100 amps, and from my experience a 5s setup is happy with a battery capable of producing 80 amps. Everything stays nice and cool and runtimes are better. Most of my 5s systems use a pair of 2200 20c 5s packs wired in parallel. So I have 4400mah at 20c= 88amps continuous. Those packs never get warm and do not go very far out of balance, so I know I am not drawing them too hard.