adjustable vs non-adj LCA

rwboring

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For the daily driver is it worth it to go adjustable? or are non-adj and relocation brackets enough?

On my last "newer" mustang I put non-adjustable and they still made a huge difference, mostly over the lateral movement because of the bushing (and actual structural steel over light gauge)
 

Tob

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You don't want the bushing in a control arm, lower or otherwise, restricting "lateral" movement under normal dynamic conditions. That is the job of the lateral locating device, be it a panhard bar, Watt's link, or otherwise. A bushing that induces or imparts a measure of stiffness that restricts freedom of movement in that plane is inducing bind - something you do not want.
 

rwboring

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You don't want the bushing in a control arm, lower or otherwise, restricting "lateral" movement under normal dynamic conditions. That is the job of the lateral locating device, be it a panhard bar, Watt's link, or otherwise. A bushing that induces or imparts a measure of stiffness that restricts freedom of movement is inducing bind - something you do not want.

Yep, that's correct but there is a difference in grabbing the lower control arm (disconnected from the axle) and being able to move it several inches left and right versus 1/2". I guess I was referring to stiffness when I meant resisting lateral movement, I am quite aware that there is no way for a LCA to limit lateral movement but if you take the "play" out of the system it has to help.

The same as the light gauge comment, no matter what the cross-section is of that light gauge the stiffness properties (I) would have a hard time competing with HSS structural steel (or a round cross section).
 
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Tob

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...there is a difference in grabbing the lower control arm (disconnected from the axle) and being able to move it several inches left and right versus 1/2"

Ryan, it shouldn't matter whether the arm swings 12" left or right (envision a rod end on the attached end). Bind at the bushing, such as in this case, can induce snap oversteer (among other unwanted handling characteristics). The bushings at the control arm should not restrict freedom of movement beyond any articulation necessary to accommodate the axle.

That said, the factory has designed in a certain amount of bind, which can affect spring rate. When you reduce the amount of freedom or articulation, you add bind into an already compromised system.
 

biminiLX

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Performance wise the adj. will always perform better and allow you to adjust and center the axle, the tradeoff is more noise.
This is not my DD and I'm more focused on performance so I went double adj., if too annoying I will go with the chassis side bushing.
The arms are cheap enough, if you don't like them swap them to non-adj. IMO.
But either way, they will make a huge improvement.
-J
 

rwboring

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Ryan, it shouldn't matter whether the arm swings 12" left or right (envision a rod end on the attached end). Bind at the bushing, such as in this case, can induce snap oversteer (among other unwanted handling characteristics). The bushings at the control arm should not restrict freedom of movement beyond any articulation necessary to accommodate the axle.

That said, the factory has designed in a certain amount of bind, which can affect spring rate. When you reduce the amount of freedom or articulation, you add bind into an already compromised system.

we are on complete different pages... i know the physics behind of it... ill just leave it at that :beer:
 

rwboring

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Performance wise the adj. will always perform better and allow you to adjust and center the axle, the tradeoff is more noise.
This is not my DD and I'm more focused on performance so I went double adj., if too annoying I will go with the chassis side bushing.
The arms are cheap enough, if you don't like them swap them to non-adj. IMO.
But either way, they will make a huge improvement.
-J

yeah i just don't think i would do the minor adjustments...
 

BMR Tech

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I don't think, looking from the outside-in.....that you guys are on different pages.

I think Tob is stating to simply let the lateral locating device do ANY lateral re-enforcement...or "locating" and rely on the LCA for what the LCA is meant to do - which is to provide a means of energy to be transferred, as well as maintain a consistent thrust/wheelbase under varying conditions.

I completely see your thought process on this, and it is actually very complex. When you get into the lateral characteristics of LCA movement - you open up an entirely new can of worms..

Just keep in mind, the more you increase lateral stability on a LCA, the more you increase anti-roll stiffness when cornering - and the more you increase the "feel" of snap oversteer. Of course, I am speaking in terms of an LCA that does not feature rod-end/heim or spherical bearing.
 

BMR Tech

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And to answer, typically a set of non-adjustable LCa and Relocation Brackets will work, for most users.

I, personally, recommend an adjustable style LCA with a bearing on the axle end, at a minimum, AND relocation brackets. This offers the best performance, with the best available adjustment.
 

rwboring

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I don't think, looking from the outside-in.....that you guys are on different pages.

I think Tob is stating to simply let the lateral locating device do ANY lateral re-enforcement...or "locating" and rely on the LCA for what the LCA is meant to do - which is to provide a means of energy to be transferred, as well as maintain a consistent thrust/wheelbase under varying conditions.

I completely see your thought process on this, and it is actually very complex. When you get into the lateral characteristics of LCA movement - you open up an entirely new can of worms..

Just keep in mind, the more you increase lateral stability on a LCA, the more you increase anti-roll stiffness when cornering - and the more you increase the "feel" of snap oversteer. Of course, I am speaking in terms of an LCA that does not feature rod-end/heim or spherical bearing.


I understand, my point is if the bushing sucks and/or the material is flexing anywhere along the length of the LCA it is putting MORE movement into the system then needed. Light gauge steel even in complex shapes doesn't typically have the strength of structural steel. Essentially that load path of energy transfer is much better through structural steel...

I know they are not what resist the lateral movement... ive had plenty of classes in dynamics, statics, dynamics of machines, etc... all im saying is the fact that aftermarket are better in several ways... and from what I saw the last time I did a swap (on a 2003) the stock ones were shitty light gauge steel and the bushing seemed to be soft as hell which are both horrible for the load path of energy transfer.
 

BMR Tech

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Gotcha.

Yeah, 1979-2004 Mustangs and 2005+ are a completely design, in terms of rear suspension. What works best on a triangulated 4-link, may not even be a benefit to the S197 3-Link. As a matter of fact, lateral rigidity in a triangulated 4-link does wonders in terms of feel, yet in actuality - does more harm than good.

I think you should be more concerned about articulation characteristics, adjustability (thrust angle), overall strength, and Instant-Center / Anti-Squat settings. Those are going to weigh more on the performance of your car, in terms of LCA benefit, than lateral properties.

If you have a LCA that moves 1/2" laterally - and one that does not, your benefit from it NOT moving will primarily be noise....and a little bit of "feel". Maybe.
 

rwboring

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Yes yes yes now we are going where I wanted... In order to worry about angle and such you need adj... Is it worth it...

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BMR Tech

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Yes yes yes now we are going where I wanted... In order to worry about angle and such you need adj... Is it worth it...

Posted via Topify using Android

Post #9

And to answer, typically a set of non-adjustable LCa and Relocation Brackets will work, for most users.

I, personally, recommend an adjustable style LCA with a bearing on the axle end, at a minimum, AND relocation brackets. This offers the best performance, with the best available adjustment.

Yes, adjustable is "worth" it....there is no doubt sir.

:beer:
 

rwboring

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Sounds good... My point was I knew they helped even when non-adj and all they are then is strength and bushings... How much MORE do u gain from adj... That's all... If it only took the car from 78% to 81% it prob isn't worth it to me... I wasn't trying to get into a great debate on suspension geometery

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Adjustables let you zero the thrust angle which reduces oversteer when the car breaks traction. There are many that freak out when the rear end of their car starts to articulate left or right due to the thrust angle being off. The more thrust angle you have the worse the amount of oversteer potential you can induce.

That is the sole purpose of the adjustable rear LCA's IMO. Reducing oversteer creates a more controlled vehicle.
 

Ky GT500

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Adjustables let you zero the thrust angle which reduces oversteer when the car breaks traction. There are many that freak out when the rear end of their car starts to articulate left or right due to the thrust angle being off. The more thrust angle you have the worse the amount of oversteer potential you can induce.

That is the sole purpose of the adjustable rear LCA's IMO. Reducing oversteer creates a more controlled vehicle.

I kind of liked that little side stepping my car did when stock. :coolman:

Just point and shoot now,,which is a major adrenalin rush for the heart when the beast starts growling. Man this thing gets gone quick!!

Sorry,,little off topic.
 

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