90 - 93 Van Diemen set up

[John Green]

Now that I have solved my piston issue from a previous thread (thanks to all that helped...switching to a set of J&E pistons with circlips).
Anyway, I am refurbishing all the suspension a-arms with new rod ends after chasing all the female threads (hmmm, is that even allowed anymore?)
Looking for baseline measurements for the new rod end measurements where the a-arms attach to the chassis and the gearbox. Any good place to start?

Thanks!

[alangbaker]

I know Primus will send you set up data for a lot of Van Diemens for the price of the postage, so I'd start there.

[Nardi]

Brad at Primus and maybe Rick Kirchner should have a "map" that provides the basic dimensions you're looking for. As I recall, Rick has a wealth of useful info.

[Rick Kirchner]

I went through a process of modeling the suspension with Steve Lathrop last year. Made a precision trammel bar (there's a post on that here somewhere) and found some interesting stuff - like my left and right arms appear to be jigged the same, but they aren't - resulting in the caster being off quite a bit from one side to the other even if I set the leg distances the same.

Also figured out my left side gearbox suspension mounting pad was machined wrong (or it could have been the right, but it was easier to put a spacer under the left mount).

i found it easy to do all of this by removing the shocks and tires, putting blocks under the chassis to simulate ride height, and then using a lab jack to set the axle height where it needs to be. Then I put it all back together and did a final check.

I have the car on the platform now to raise it because all the tracks out here have gotten really rough in the last couple of years. I was bottoming the car hard in 4 places around willow springs this weekend. I can verify some things and then send you my data. I think the Primus stuff is on the website but I have that too.

[chrisw52]

add a +1 to that trammel bar. That has become my new favorite tool when setting up new/refreshed wishbones

[Rick Kirchner]

The Campbell bar I purchased had 1/8" of slop. You could tune it out if you were careful. The one I made out of a ball screw had essentially zero slop. The only thing limiting the measurement is you eye. Maybe I ought to put a DRO on it.....

[mark elder]

You all need one of these

Suspension Measurement Jig - Gyrodynamics

I bought a few extra bits to be able to make a big T with 3 tapered pins so I could match a complete wishbone (not just the 2 pin setup that allow just distance between 2 rod ends). So I got another length of 80:20 and another tapered locating pin plus 2 right angle joiners (I live in a metric world and could not get 80:20 here in NZ).

Mike was an absolute pleasure to deal with. Highly recommended.

And the jig is amazing.

[Rick Kirchner]

That 8020 essentially fixes the problem I had with the campbell gauge. It was just a piece of C-extrusion with a slot milled down one side, so not much structure to support the cones.

I might have to put a chunk of 8020 down the side of my device - I like the idea of making a T out of it.