Rear End set up

Any ideas on this, when I go back and look at my launch tracks you can see the initial patch, then the tracks make a noticable shift/jump towards the driver side - then a nice set of straight tracks.

Stock springs, with slapper bars, so not a lot of science in this, just never seen it before.

Have you tried pre-loading the bars? Locking the front spring leafs together?

This is assuming you have a TRACTION-LOC and the clutch pack is good.

Yes, I have it pre loaded with the front hoops on the bars, equal load where there snubbers are about a 1/8 inch from contacting the springs.

Its a spool so the power is equal to both tires, and looking at the contact patch and resulting rubber on the drive way, appears to be equal load each wheel.

I dont have the slicks on it right now, using street radials until I get this figured out. Wonder if it could be a weak spring. The prev owner, who ran it on the track, had a wedge under the pass side, I took it out to level the car. I also had a bit of twist or something when I would shift hard or dump the clutch, taking the wedge out took a lot of that out. but it still is making a visible shift to left, just dont feel it as much as I used to.

50/50 drag shocks I guess? Maybe the right rear is coming up enough to make it walk sideways?

Maybe AIR-LIFTS or an extra leaf in the right side to pre-load it?

CAL-TRACS?

The best way I think is to have someone tape the launch with a movie camera and that may tell you what is going on.