Trailing arms help

[winders]

Frank,

According the folks at Jerry Woods Enterprises, the spring plate mount gives you a more linear and more appropriate motion ratio as the suspension moves. In other words, mounting to the spring plate is better than mounting to the trailing arm.

[mreid]

The sway bar mounts to the spring plate by replacing the eccentric adjuster with an eccentric bolt as shown in this diagram:

http://elephantracing.com/documents/911%20Rear%20Swaybar.pdf

[Flieger]

I've got some new Tarett 22mm RSR style bars available in case it helps you. The rear is an early bolt spacing. Bought them but decided not to use them.

[frankc]

Originally Posted by winders

According the folks at Jerry Woods Enterprises, the spring plate mount gives you a more linear and more appropriate motion ratio as the suspension moves. In other words, mounting to the spring plate is better than mounting to the trailing arm.

I wonder if this is assuming an aftermarket adjustable bar vs. the OEM bar. One other aspect I didn't care for on some of the spring plate mounts that I've seen is that the distance between the spring plate and the drop link is quite long, resulting in a cantilevered geometry. Obviously it must be ok as I haven't heard of these fasteners failing, but it just looked stressed to me.

There was a bit of discussion a while back on the drop-link topic as well:

Adjustable Rear Drop Link Attachment

[winders]

Originally Posted by frankc

I wonder if this is assuming an aftermarket adjustable bar vs. the OEM bar. One other aspect I didn't care for on some of the spring plate mounts that I've seen is that the distance between the spring plate and the drop link is quite long, resulting in a cantilevered geometry. Obviously it must be ok as I haven't heard of these fasteners failing, but it just looked stressed to me.

There was a bit of discussion a while back on the drop-link topic as well:

Adjustable Rear Drop Link Attachment

Well, the whole point of fasteners is survive stress. As long as the fasteners are strong enough all is fine. Plus, the geometry is otherwise quite a bit better with the spring plate mount versus the trailing arm mount.

I use Tarett sway bars on my race car. I have to use the trailing arm mount because of the raised spring plate front (chassis) mount on my car. The drop links would run into the frame rails if I used spring plate mounts. I had to get custom drop links from Tarett and mess around with spacers to get everything setup so the heim joints would not bind. I would have had no issues if I could have used the spring plate mounts.

[RSTarga]

Don't the aluminum trailing arms have a different shock angle than the 70 steel ones? I think they may require some machining there too. There are clearance issues at the top shock mount.

[78-911SC]

You are correct RSTarga. Go to post #20 and it explains how to go about achieving the proper angle and clearance. There are a couple ways to do it and I plan on doing the one that requires removing 1".