There has been some discussion on this recently, and I desire to know if I understand everyone's contention of why a sway bar may result in tearout.

Here are my assumptions. Please correct if I'm wrong:

1) The roll stiffness of a car is dependant upon, among other things, the wheel rate of a particular suspension. Thus, a lower overall wheel rate will result in lower roll stiffnesses and therefore higher roll angles.

2) The wheel rate is a result of the spring rate and sway bar rate, subject to motion ratios, and added as parallel springs.

So, for example:

100 lb/in spring + 22mm swaybar has a lower wheel rate than 200 lb/in spring + 22mm swaybar. Thus, the roll angle at a given lateral acceleration will be greater in the 100 lb spring combination.

Because of this, there is increased deflection in the swaybar.

As a result of the increased deflection in the swaybar, the mounts (bushings) see increased loads.

These increased loads may cause the bushings to extract themselves from the mounting holes.

Am I correct?

 

Pretty much.

Correct installation (including lubing the bushings regularly) will go a long way to stopping the problem.

In really simple terms...
Using stiffer springs makes the swaybar work less, so less stress on mount points.

The problem usually arises on street car with soft lowering springs and huge rear swaybars (21mm+). As this is the common setup for both "riceboys" and dual use autocross cars, the problem comes up fairly frequently in discussion forums.

 

I think only RR98ITR could have explained it any more complicated then that.

 

In really simple terms...
Using stiffer springs makes the swaybar work less, so less stress on mount points.

This is the result I was trying to get at, but including the justification for the result.

Sorry for the complication, I just wanted to be thorough.

 

Off topic but this is how I repaired my subframe from using a 22 mugen rear bar.
http://www.imagestation.com/album/?id=4291503975

 

Beaks kit = no problems
https://honda-tech.com/zerothread?id=408156


[Modified by mrlegoman, 2:18 PM 2/14/2003]

 

I've got a question or two.

What exactly does a tie bar do to assist the 22mm anti sway bar?

And what do you use to lube the bushings with?

 

Somebody correct me if I'm wrong, but in a nut shell the sway controlled the vertical forces and the tie the lateral forces. The sway bar does just that, it reduces sway. The tie bar is more of a frame re-inforcement, like a tower bar, and reduces body flex.
I would think any high-temp greese would do. ES bushings come with a little tube that seems to last a while.


[Modified by mrlegoman, 2:52 PM 2/14/2003]

 

You hit the nail on the head. The bar puts stress on the subframe, and after taking many corners the holes will begin to wear out. After one track event, and some hard street driving, my holes are starting to wear and have become bigger. I took my bar off until I get a reinforcement kit.

 

Ive had a BSQ kit with JDM 23mm bar on my GSR for 2 years with a few auto-x and a bunch of HPDEs and no problems, although it does creak a bit in the rear subframe under very hard cornering.