Just got back from racing and the 20, 30, 7 diff oil is the ticket. I also ran Primes, but forgot to bring the Positrons to compare with. It was a long day, noon til 9:45 PM, then 2 hours back home, arghhh! I am going to put the 6.5 motor in to see if it does better than the 5.0, as I was lacking power. It handled so much better, I was able to bump from the B main to the A. Jumps were also more controllable as well.