I've assembled and tuned a couple of asphalt bikes for local guys. The main things that I found made a difference were gearing, clutch, less timing, slightly less compression, and tire width. There are two schools of thought. Some guys like to set it on kill and charge hard right from the hole so the bike is hanging it's lungs out at the finish. Other guys like to get to leave ok, and then really charge on the big end. IMO, I've seen faster accelerating bikes MPH less but still be faster, and that's how I like to do it. It's worked for me on two bikes I set up for drag guys, as well as my Oval racing set ups.