Best way to launch a stock EVO is to pulse the throttle between 4500 and 5500 over and over at the tree, and feather out the clutch at the high end (5500 RPM). That will give you the best results..... not sure how long the stock clutch will last doing that on a regular basis though. Looking at your traps, looks like those 19" wheels are killing you though. They may be pretty, but they are also heavy as hell 
Keith
Keith