It's geared for about 35mph. There is a bit of drag on the CD, i noticed before putting everything together. Also there is a sort of ticking sound from the rear while free-rolling without the motor attached. Doesn't seem that the rear diff slips under power or anything though. No strange noise under acceleration at all. Also, I think my maxs is heavier than the hellfire. I'm just guessing, but with all the aluminum on the maxx it's quite a beast.
Whats your EMaxx setup? Which version do you have? Just from your photos I would think that the Hellfire is a liter setup as well. Are you sure that you dont have a small short of some kind going on there? I am sure that you will get to the bottom of that one. Good luck with that.