HELP HERE ! Mamba maxx and feigao 9xl setup slow as hell!!!

I've just got my mamba maxx and fiegao 9xl and tried it without it installed in my truck cause i wanted to feel and hear the power. Well it was a big dissapointment cause a mabuchi motor would go faster!!! Is there anything wrong im doing here? My battery is a 2s 4000mah. Should i use two of those? I need some help here cause i was told that this setup would kick an hv maxx. Could have it been initial setup of esc? tried to update it thru usb still same power output on engine!!! Help