In helping my friend initially set up his tube chassis 4 link I took the recommendation from this forum and set it up with an IC of 40/6 (if I remember correctly). He's still looking for the IC diagram I prepared when we originally set it up. Anyway the car launches good and goes straight but it is hitting the tires very soft. I need to raise the IC for a harder hit and my question is about how far should I move it per change until we're satisfied?