Hey Roger...
My problem is not traction at all. Our new carpet layout has a part of the track that I have to work on. It is right after a 180 right turn that I hit some bumps the car gets really upset and as soon as the wheels hit the ground I meet another single jump that send me to a wall ride.
The car is fast there but not safe and I tried to give some more pack in the rear, changed to fewer holes but it was more or less the same. Try some weight in the rear as well but again the difference was minimum.
Maybe the C/C in combo is too narrow and I was thinking if I ake the rear end wider mayber it will help the car calm down faster before hiting the single