There's a couple things to try:
Longest camber links possible- it will keep the tires upright, and won't suddenly break traction.
shorten the wheelbase-will add rear traction
Try moving the lower shock positions in one hole- that will soften the suspension overall.
Run o-rings under the upper chassis plate screws-should help add more flex and grip to the car
One thing to think about is the hinge pin mount heights (roll center) on your car. Raising the roll center should allow you to run super soft springs and get some mechanical traction. Of course, i haven;'t raced on a wood floor, so i could be completely out of line