XLS rear bump-steer

[XLR8]

After assembling the re-re XLS’s rear suspension in accordance with the manual, I’ve noticed what I would consider an excessive amount of rear wheel bump-steer (perhaps 5 degrees or more per side). The manual has you adding a 2mm spacer under the inboard ball-stud so I added another 1.6mm nylon washer and that seems to have removed most of the bump-steer (total spacing is now 3.6mm). I believe that a small amount of rear bump-steer would be beneficial on a loose track to correct for oversteer but, as assembled per the manual, this seems to be way too much and could possibly result in some strange handling characteristics in rougher areas of the track. I’ve had a look at my old original XLS and I have its inboard rear ball-studs at about the same height setting (about 3.2mm total spacers). I’m curious if anyone who is running their car has found a need to dial back on the rear bump-steer and if you could please also describe your track conditions. Thanks!

[stuey]

I found the same, and added a similar washer which all but removed the bump steer. I did the same to the front steering ball joint in the hub as there is a lot of bump steer on the front too.

[XLR8]

I found the same, and added a similar washer which all but removed the bump steer. I did the same to the front steering ball joint in the hub as there is a lot of bump steer on the front too.

Hey thanks for replying. Yeah, in fact I am doing precisely the same thing to the front (added 3 x 0.6mm thick nylon washers). Its good to know I'm not the only one finding this problem.
This seems pretty basic; I would have expected Schumacher to have this sorted out before they launched the kits. Anyway, it's an easy fix and could be attributed to the challenge of building the kit.
thanks again.

[stuey]

Ironically, the original manual shows these washers to reduce the problem, but not the new one.

[pedro]

I think the problem with the front end might be that the car uses the original steering rack not the xls one that is about 5mm or so wider on each side?

Peter

[XLR8]

Sure enough, you are correct Peter. The re-released XLS actually uses the same width steering rack as the original SWB car. Do you reckon they did that for ackermann; effectively providing a bit more aggressive steering for the longer wheelbase car?
Anyway, for accuracy, I really should pull apart the steering on my vintage XLS restoration to install the correct rack.