R&P on a BJ front end?

[Michael Ghia]

I think that unless you can mount the steering rack so that the track control arms work in parrallel with the suspension arms, you'll always get bump steer.
The trailing arm suspension runs in an arc, so if you were to mount the rack to the bulkhead, you'd get terrible bump steer IMO.
Just thinking aloud

MG

[GS guy]

I agree with your assessment Michael, there's really no "right" design steering box or rack that works perfectly (geometrically wise) with the trailing arm suspension design. Even the OEM steering box and pitman arm falls short in this area. In the original design I believe the geometry is as best it can be - given pitman arm length and tie rod placement, spindle arm length, trailing arm length, etc. It's all designed to work as an assembly with all the angles worked out to minimize bump steer during travel (and steering). But, as soon as anything changes - like ride height settling or lowering, all that carefully created geometry starts going out the window. Rotating the steering box on the beam brings it back somewhat, bump-steer kits for the extreme lowering, etc - But from what I can see it can never be even as good as it was originally intended once you change anything. But, with all the succesfully lowered cars on the road for the last 30+ years, it's still not too bad!
Straight line - I don't see the different whether the driver's side inner tie rod is mounted to a pitman arm or rack end - as long as the mounting points are the same, bump steer should be unaffected. Things will change when you add steering into the equation, and this is where I think the rack will fall short. However, re-locating the inner tie rods to near the center of the beam (or car centerline) apparently goes a long ways towards minimizing the unwanted effects - as evidenced by all the off road cars that have been successfully running this design for decades. Just need a similar rack with offset input shaft to run it on a road car.
Jeff