RE: Upgrading the Hyper ST RTR
I have to agree with KB on this. Tires should be your number 1 priority. You can have the best engine out there and if you can't hookup then you just got a great engine that doens't do squat. Do yourself a favor and go to the track you are going to race on and see what tires ppl are running. Ask what hooks up good and go from there.
Good luck.