I'll be at the Solo National Championships in September. If shaving street tires got you any gains someone would be doing it. I've been running them for two years and haven't seen anyone shaving them in that time. People were shaving the old Toyos, but those aren't really used anymore. I'll be there on Bridgestone RE71s with just a few runs on them to scrub them in. I suspect the 700 or so other street tire competitors will be on unshaven tires too.