Del-A-Lum LCA bushings

[74_5.0L_Z]

The Futofab is a much better design. On the Fotufab tension rod, the bolted connection between the dog leg and the clevis end can accommodate the changing angle between the control arm and the tension rod as caster is adjusted.  On the T3 rod, there is a rigid connection between the dog leg and tension rod.  The holes in the dog leg would have to be oversized to accommodate any caster adjustment and will limit the range of caster adjustment available.

[trackzpeed]

Agreed on Futofab points..... I'm just a little concerned about the amount of stress placed on that dog leg so close to that pivot point.   Thanks for the input.. Jim 

[JMortensen]

Hmm interesting. I guess the leaning back of the strut is just used to achieve anti-dive characteristics or a different motion ratio in E30's?

 

Quite interesting is there* a reason people don't make this type of arm? Even the drifters I am familiar with tend to run just the typical box section extended LCA and longer adjustable TC arms, a one piece like that would give some fairly large amount of room to pocket the wheel for steering angle.

The leaning back of the strut is what gives caster. It also changes the motion ratio, but not a lot unless the angles get really extreme. 

 

I don't think a lot of people drift Zs, that would be one reason. The other I can come up with off the top of my head is that the TC pocket in back is at an angle. Most of the LCAs with this design that I've seen have the rear pivot pointing straight ahead and then they use an eccentric to push the rear pivot back and forth and adjust caster. That wouldn't work so well with the pocket at an angle. When you move it out to adjust caster positively, you would simultaneously be moving the pivot back, which counteracts the caster gain. 

[seattlejester]

That makes sense. Not sure how many people would be comfortable with welding in new suspension attachment points. Thanks for clarifying!

[rturbo 930]

On 3/7/2017 at 7:07 PM, JMortensen said:

I'd bet that it wouldn't be too hard to do a single piece LCA. Just has to have a rod end at the front and maybe a inner tie rod or something like that at the bucket. So long as the arm is shaped so that the rear pivot can move without binding the joint, should be OK. Would be harder to do with a  rod end in back. I'd bet some drifter has already figured it out. They need the wheel clearance for more steer angle so single piece LCA makes a lot of sense for them.

I stumbled on this a while back. I think it was something Monzter did. Thought it was an interesting design, mostly because I've never seen anyone else do it.

 

 

[seattlejester]

My initial feeling would be that it would bend, during braking as you would be applying load on a long threaded piece. 

 

I'm curious what the experience has been.

[BoonZ]

I  had a 240 with eccentric LCA bushings. They  were  pulled from service in poor shape. The aluminum had deep groves, Bushings tapered. (Maybe from the arc generated by the TC arm). They were made to run without lube.  

The aluminum is to soft for good soft for good wear resistance. If you can keep  the dust out and lube it,service  life may be OK for weekend use. 

I have Moly filed Delrin on the inside of the rear a-frames. They have about 30K on them. The heat from the exhaust warmed one next to it and it would stick. Had to increase clearance from .002 " too .010". 

Next time I will use PEEK or Torlon with a mono ball in the front. 

[Chickenman]

Just a bad design and were a bad idea for a single LCA design with Mac Strut. . The Herb Adams Del-Alum bushings for Upper and Lower controls rams Use a hardened aluminium outer casing, very thick with a thin Delrin Liner and a hardened inner steel sleeve. They are greasable. All the movement is between the Liner and the greased inner steel sleeve.  The Delrin liner does not move in relation to the outer shell. The Zerk fitting pins the two together. Well engineered and they last darned near forever. 

 

 

Edited December 14, 2017 by Chickenman