there are a few things to look at that have not been touched on. first is the battery. if you want something with punch, get the high C rated batteries (70c+). not too many people build custom batteries any more because of lipo and the SMC batteries are great for the money. production is about the only way to go. you have the esc so we wont go there. the motor is a huge thing. have you looked into timing at all and whether or not it is available in your classes? our local blinky stock class can run a 17.5 turn with timing or a 13.5 without. most seem to run the 17.5 with timing...for two reasons. timing is huge and can make a motor scream. the other is that you can do a rotor swap for a high torque 12.5 rotor on a lot of these motors and it is ROAR approved. there are a lot of hot motors out there...pick a brand and run with it. I picked up two 17.5t trinity epic d3/d3.5 with high torque rotors for about $50 each used on here and they looked brand new/flawless. sooooo...long answer short: high C rated battery (70c+ and a good brand) and a good 17.5 motor with a high torque rotor and some timing if available. check those two out and it will make a world of difference with your ESC.