well there is I think but its going to cost you big time
http://www.okami.org/motor.htm
there is also a build your own motor thing on carmo world but you have to have it shipped from tialand
Or you could just add another cell or 2
try lightening the chasses or simething else like making a carbon fiber pan chasses and attach the front and rear
I have heard others say thr plasma dash is realy fast mabie you got a bad one