XRAY - Model racing cars

although this is fun it doesnt give a good run time .....my car when im entering the corner off power flings the tail out on power entry isnt as bad but its a case of power sliding ...with the ride height at 6 i noticed the rear suspension was very hard the ball joint was lying ontop of the rear upright so i had to put a spacer of 2mm between the joint and the hub to give me suspension travel is this normal ? it aint in the instruction book when building it ......the rear diff is fine nice and smooth i played with droop ,shock postion ,springs ,roll centre and rear anti dive nothing worked any help would be great we are racing indoors on polished wooden floors

Its hard to say unless you post your full setup in the Setup Sheet section for us to see. I use 2mm shims to space out my lower shock ball ends from the arm without any problems. I do this to get a better angle for the shock though as I use the inner holes on the arm.