long story...... but I am completly baffled.
The car is a track car. I run 10 HPDE days per year.
I had inner tie rods installed by a very reputable vette shop.
get the car back, every thing is great. few events later, the steering wheel center line keeps changing after every turn. Meaning, if I turn left, the wheel would return to "center", but it would be a different center than if I turned right. The change in steering center is very noticable. especially while on the race track.

So I got under the car, and tightened down all 3 rack bolts, figuring the rack may be sliding back and forth, which would cause my problem. It seemed to help a little, but didn't solve the problem.
So I take the car back to the vette shop and have l poly rack bushings installed, figuring maybe the movement is the rack bushings. nope, still have the same problem.

Car also has a camber brace, so now I'm thinking that the camber brace may be pushing too hard on the other control arm tower, and the towers are flexing. (the point where the control arm bolts pass through). so I just pulled the camber brace out, and not much has changed.

I hope I'm explaining myself correctly... But I am baffled, and so is the vette shop. It's hard to imagine the rack slidding back and forth because bolt goes through directly through the rack, and through the frame....

any clues, as I don't know what else to do at this point. Nothing is loose, the car handles great, except this steering problem.
I also have a turn1 pump, but I can't see that affecting this.

 

Might be loose components inside the rack. Is the steering effort firm and smooth (no notchy feel or spots where the wheel seems to hang up)?

The camber brace by itself should stiffen everything and not allow the frame or the upper A-arm attaching plates to move. There are separate bolts holding the upper A-arm mounting plates to the frame. Are the bolts tight and is there any elongation of the holes??

How about wheel bearings? Grab the wheel at 12 and 6 o'clock and see if there is any movement. Are the outer tie rod ends tight?

The pump may be OK but isn't there a internal valve that controls pressure to the rack? That may be failing or working intermittently.

 

The steering effort is perfectly smooth. no binding at all.
I saw those attachment bolts through the frame, and they are indeed tight. I got another 1/4 turn out of them, but they were plenlty tight.

I can't see this being a pump problem, as it is something to do with centering of the steering wheel. not how it returns to center, but where the centerline is located.

What is inside the rack that can change?? nothing seems loose....

 

Anything weird with the alignment?

Too much toe out? Uneven caster? Just a few thoughts off the top of my head.

Self-aligning torques come from caster and pneumatic trail, if I'm remebering correctly. How much of a difference in wheel centering 1-2 degrees or more?

 

Just for drill, is the steering shaft from the gearbox back to the column tight? Is there any sign of wear in the splines of the shaft or couplers?

 

The steering shaft, (intermediate shaft) is new, and tight.
actually that is the first thing that came to mind, but it would be very difficult for the intermediate shaft to skip shaft alignment. at least on the bottom end where it is ablong shaped.