The esc has no motor limit and handles up to 10 cells. I ran a 10t speed gem and it was gonna smoke the batteries. I heard the titian 12t has an 8 cell limit. Never confirmed it. The titian is probably pushing its limit now; it gets hot even with a heat sink on it. I have had much better success it seems running a smaller(more turns) motor and upping the volts. As far as pure speed is concerned. Right now the truck is geared 20-78 and probably isn't even coming close to 40mph. Lots of torque, though. All I do with this rusty is bomb down the road full speed and hit a 3ft tall jump that sends it to a nice down hill landing. 45ft is the longest distance I've cleared. I was flying 35ft with a 3600 6 cell. I need more speed. Buying one more motor for this truck and calling it good. VXL time this summer. I figure I might as well get as much as I can outta what I got.