I'm reasonably happy with the current front end setup, just working on refining it a little. Looking at the tyre wear I've discovered that now it has a decent amount of positive caster (just over 5 degrees) and stickier front tyres, it doesn't need quite so much negative camber (currently around -1 degree). However I can't adjust this out via the shims without compromising something else, so I decided to use an offset front lower bush.
You can buy these in a particular brand (Noltec I think) but they are expensive and I much prefer the Superpro bushes. I figured that an old set of offset crush tubes from an IRS Commodore (camber/toe adjustment) would be a good starting point. They have just slightly more offset than I wanted, aiming to bring the camber down to about -0.5 degrees. So I offset machined them, any reduction in overall diameter is also good so I don't have to remove any more of the polyurethane bush than I have to.
The crush tubes are also longer than required, reduced to length and added some spline back to the end. Not quite as per original but I figure its enough to give it some bite and stop the pivot from turning.
Remove the original crush tube and machined out the inner diameter of the bush to provide the same snug fit. Superpro puts a "double helix" (left and right hand spirals) groove on the crush tube itself in this particular bush design, with nothing special on the inner diameter of the polyurethane.
Unfortunately the coarsest thread my mini lathe will cut is 8 tpi and to do this automatically would need more like 2. So I made a sticker template
and cut it with a small die grinder burr. Not the prettiest but I don't think the grease will know the difference.
Fill up the grooves with grease, push the crush tube into the bush, ready to go.
The original bolts from the Commodore setup are in good condition and are threaded far enough up that they will still work with the slightly shorter length. They have a spline just below the head which engages the inside of the crush tube (see inside the bolt hole in first pic) allowing it to be turned by turning the bolt head so this will work nicely.
Next up to install them and all the other hardware above.
Edited by 76lxhatch, 21 July 2017 - 11:22 PM.