Since your running the mod classes, are you running a turbo?
ISR wouldn't approve the fourstroke turbo for the lower mod classes when I built the sled, they told me it was a gray area that would possibly limit me to open mod status, so I proceeded with a high compression natural aspiration motor package that dynoed at 183 hp. The up side is that this allowed me to focus my efforts almost entirely on the suspension and chassi, and I was able to learn how to race the sled with a horsepower handicap. At 506 lbs wet, I am still at a weight disadvantage when compared to the 2strokes, but the good news is ISR has backed off the restrictions regarding boosted fourstrokes for 2011, and I will be racing a custom turbo setup next year.:heh:
How is your subframe holding up with all the hit's your taking?
I didn't even attempt to use the stock sub,... I have custom titianium supports bolted into the Diamond S chromo sub, which has proven to be strong enough to survive the wacked out junk we race in. There are lots of pics, and descriptions of the mods done to this sled in the Plan B Mission impossible thread on the build forum.