After you tighten the screw of the ball diff, hold the drive cup on both side and try you best to turn the pully, if the pully slip which means the screw is not tight enough. Whn you get to a point that the pully dors not slip anymore, try to loose the screw alittle bit. What you really want is to get the 岩岩好 position of the screw. You have to trail and error this process couple of time.
You will have to rebuild your ball diff after 1day playing
Usually, the default setting of ball diff. can refer to the manual.
In addition, you can refer to the set-up sheet of professional drivers (download for web site of manufactors).