at 16 lbs the car wanders so bad i was hoping i stayer off the wall,,,at 17 it did the same not as bad at 20 lbs i still get good traction and the car stays in the middle of the track,, all 16,17,18,19 & 20 nets me 1.75 60'. also the track was not prepped at all,, got Mike R's links will install and set to .o on chamber that should make the tires flat to the ground. jim