jimbob
i would put money down that your 4wd system is not operating correctly!
i had the same problem(r32gtr) with traction in 1st and sometimes 2nd gear accelerating in a straightline it would step out or just bounce of the limiter, that was with approx 350 kw's @ 4 wheels.
i have more power now and no traction issues in a straight line.
it can be a number of things wrong , pm me if you would like some ideas.
cheers russ
btw man after my own heart, i have an evo9 too, mine is silver.