does any one know if there are engines out there other than the mach .15 with a little more power that can easily be converted over without much expence? and also how do you tune a mach .15, i think that just may be the problem... also, can you use front ribbed tires on a road course without much wear... i have speed hawgs for the rear but wasn't sure if i needed to purchace some for the front as well... thanks,