So here's one that has Art and I perplexed. Car is a 94VD FC. Not a lot of stiction in the joints, as many are nearing end of life.
Recently had the car completely apart, measured the frame, made sure everything was jigged perfectly and as symmetrical right/left as possible. This time I'm setting the car up per the original 1995 setup sheets - no front pre-load. pushrod lengths were set at a length suggested by the guys who ran the car back in the day when it set the Willow Springs track record. This means front ride height is set with the lower spring perch location, as opposed to cranking the springs into pre-load and setting ride height using pushrod length. Perches are secured with setscrews.
roll car onto the scales and front left is ~50lb light compared to the right.
crank a half-turn of RR pushrod into it and get the left/right balance perfect. roll the car off, jounce the hell out of it, roll it back - and it's off again. Adjust it to perfect, repeat above, and it's off again. I'm not even converging on a solution. Near as I can tell everything is tight, and even if it wasn't these weight changes require somewhere between 0.050 and 0.100 of movement. There's nothing obvious going on. Went back to baseline and have repeated this non-repeatability 3 times now.
Thoughts?
Since this is the first time I've set a car up without front pre-load, it occurs to me that with pre-load, if you jack weight onto a corner, as long as the pre-load limit is not exceeded, the car will just teeter over on that corner and the weights will even out. Should I be equalizing the weights with front spring or rear spring instead by changing perch locations instead of goofing with the pushrods?