C4 trailing arm bracket differences?

[69427]

Trying to find out if there were any (geometry) changes in the bracket (that bolts to the frame) during the C4 run. Any experts out there?

thanks,
Mike

 

[Twin_Turbo]

I'm pretty certain they're all the same. Doug rippie used to offer revised ones.

There were several changes over the years, the trailing arms (dog bones) are all the same length (but the ones on 96 had fiberglass rods with aluminium/bushed ends). The 88 up had the abs so they have different spindles.

88 up had a new rear hub, no more drum style parking brakes but a mech operated system part of the caliper. The 84-87 ones are similar but the 84/85 is different from the 86/87 one. I think it was the caliper that changed.
90 up had different camber brackets and strut rods (less jacking, revised geometry) Doug Rippie also had revised versions of these.

 

[BBShark]

I thought I had heard that the hub on the later C4 had revised pickup points for the dogbones in order to chage the squat characteristics of the suspension. I did find this diagram on my computer, I'm not sure if it shows the revised configuration or the original.

BTW, welcome to the forum Mike.

 

[Twin_Turbo]

The wheels in that pic are the old wheels so that's either 84/85 or 86/87. I think I remember seeing that pic in an article about the 84. The body also has the trim ridge all around.

The red lines show the virtual isntantaneous center where they cross, giving the virtual swing arm. Moving those points about changes this arm and indee dthe anti squat characteristics amongst others.

 

[69427]

.........................
90 up had different camber brackets and strut rods (less jacking, revised geometry) .....................

I was aware of the change in camber brackets, but I was under the impression that the strut rods were common over the years. Were there different struts in the later years? If so, what was the change?

thanks again.

 

[Twin_Turbo]

I checked, you're right, they're all the same. Same part #.

Hey, how did you end up doing the coil overs? I saw your thread on DC (and another one) but coudn't reply.....they banned me.

Why not post a thread about your project in the project section? Quite a unique build, I think others will want to read about it too

 

[69427]

First, thanks for the strut rod info. Greatly appreciated.
I'll post some update pictures sometime soon. I'm in the middle of moving, and I'm spending WAAAYYYY too much time away from the garage (painting, yardwork, packing stuff, etc). I have a late set of strut rods laying around, but with the move (the '84 is already stored a thousand miles away) I can't even compare old and new(er) stuff.
Last, but not least, thanks for the new forum to exchange hands-on info.