Isn't STX the class I hear they may get rid of. Plus most times are less then 60 seconds. For you probably about 45-50 sec's and the times would be even closer. I don't keep up with these classes real close but isn't STS and STX pretty close in rules and both exculed R-DOT tires. If so then that is the difference. Zero mods plus R-DOT tires is faster then a whole bunch of mods and 140 tread wear of better tires. Grassroots Motorsports tested Kuhmo's Ecsta V700 against real street tires (Azenias, BFG, etc) and found a 2 sec difference in time on average. Spend your money on tires if you want to be fast. You would have to do all the mods allowed in STS to even come close to the times os a DS car on R-DOT tires. Even then you would need to be on Azenias and not the majority of tires out there. That is basically what pax is telling you.