I've been testing the car with the modifications and the rear traction did improve but i've also noticed that the rear hub has a lot more play and under acceleration the rear wobbles also a lot more then before.
I will look into it and i think i need to add an extra shim plate between the rear hub and suspension arm.
Overal i think it did improve the cars best lap at the track, my fastest time today was 1.5 seconds faster then the fastest guy last saterday with the same car, same motor and same FDR of 5.09.