Troy - if you want to lose some weight and still keep it balanced you can move a 5g piece further to the right on the motor side, or add a clip on heatsink if you don't have one already. It's the old fulcrum principle (seesaw) - the further way from the point of balance the more effect the weight has.
Ran my car on a loose carpet track Friday, traction was similar to untreated asphalt. Front and rear diffs because of the low traction, plus plenty of brakes going into the corners. I don't have all my tools yet but whatever setup I was running seemed to work well for me. The front end had a lot of grip coming out of the turns, plenty of rear grip (no tail wagging) and no torque steer punching it out of corners. 10T motor but wide lanes and soft barriers (firehose) so no really "testing" of the bevel gears. A couple of the guys tried making spools from one-way diffs (using epoxy/resin to lock the bearings) but with the low traction that wasn't the best setup at all.
Erik - ask JJ about the picture I sent him
