Lower control arm stiffening plates?

[j-c-c-62]

"The look" has a downside. Albeit small, but it's an obvious modification. If my LCA were loose and sloppy, I'd be tempted to replace them. Were the restoration to contain (for example) QA-1 suspension parts, and bolt-on chevy-like chrome parts, then sure, there is no downside to using the plates.

The claim here is there are "no downsides" or which usually means really "I have no concern about what I don't know"

 

[gkent]

If I were buying a concours restored 1 of 1 hemi Daytona and the only flaw I could find was LCAs with stiffening plates, I'd probably just make note that at some point they should be changed !! I wouldn't be an asshole about it.

 

[autoxcuda]

I’m not a huge fan of the massive plate. Just run 1” x 1 1/2” strap under the sway bar bracket and one under bushing if the sides are splitting making the swivel too loose.

Can be done with a 12” of 1” wide strap bought at Home Depot: metal strip, hacksaw, and a welder.

I don’t think the sway bar strap is a necessary deal on a street car with under 1 1/8” sway bar and mild suspension upgrades

 

[j-c-c-62]

If I were buying a concours restored 1 of 1 hemi Daytona and the only flaw I could find was LCAs with stiffening plates, I'd probably just make note that at some point they should be changed !! I wouldn't be an asshole about it.

 

[threewood]

The claim here is there are "no downsides" or which usually means really "I have no concern about what I don't know"

If we are talking stiffening plates, then we are not talking concourse restoration. What concerns are there with welding a plate to mechanically attach two pieces of metal together?

 

[j-c-c-62]

If we are talking stiffening plates, then we are not talking concourse restoration. What concerns are there with welding a plate to mechanically attach two pieces of metal together?

Since you asked, nobody has ever shown a proven need that they require any "stiffening" in the first place?

 

[Kern Dog]

“Trust the science”.

I admit, I saw an article in a magazine and just did what I read about. I didn’t push the car so hard that I found a weakness that clearly needed to be addressed. It could be that I just added weight that provided zero benefit. I don’t see how it could hurt anything though. Maybe it helped reduce noise or vibration by some small measure?
It would be good to have actual data to go by but just like it is with many other changes we make, this one was done based on anecdotal evidence much like shock absorbers selection, torsion bar and sway bar choices and tires. I used common sense based on the difference I’ve seen in reinforced wood framing.

 

[WileE]

Since you asked, nobody has ever shown a proven need that they require any "stiffening" in the first place?

 

[j-c-c-62]

Kern, your observation and understanding of the benefits of adding a shear membrane (PW) to a framed structure (2x4's?) are well proven and well understood and accepted
(I believe your PW analogy applies much better here to the addition of say torque boxes).
The difficulty in this application are the major loads and stresses are not similar, unrelated to a large degree, and unobserved (excluding say crash damage of wall impact).

 

[j-c-c-62]

View attachment 1780760

One aspect to this seemingly never-ending discussion, it's my personal observation of what appears to be incredible back breaking pretzel twisting logic to justify the plate additions, is that it's mostly by those that have already added the "stiffening" plates, and it's mostly shared AFTER they have done so, with their final closing argument often being:
"What harm can it do?"

How inspirational I say.

 

[gkent]

Yeah well ... I question all the BS stiffening crap out there - frame connectors, firewall stiffeners, rad support stiffener, torque boxes, etc. All that **** is installed on my '69 RR and the door gaps still open up when I raise the car on a hoist !!!

 

[gkent]

The problem is: too many people want to be right and will argue the point till they're blue in the face. If they were standing next to you it would be a shouting match!

 

[Sam69sat]

Americans are a funny breed. They'll bitch and moan about a Chinese copy but if an American copies another American's product and sells at a lower price, its ok !!!

That's funny. Will it be as funny when you become American in the near future?

 

[Sam69sat]

Yeah well ... I question all the BS stiffening crap out there - frame connectors, firewall stiffeners, rad support stiffener, torque boxes, etc. All that **** is installed on my '69 RR and the door gaps still open up when I raise the car on a hoist !!!

Maybe you just did a sh*tty job installing them?

 

[dodgeboy440]

"Thoughts?"
If indeed they can be justified, I am curious how one decides what is the needed correct thickness?

You asked a fair I believe sincere question, unfortunately no honest response I can give will not create a lot of strife.

Obviously….. They Increase Structural Integrity!
Why Don’t YOU The Doubting Thomas Grace Us Lower Slobvovians With You’re Brilliance
By Submitting A Stress & Deformation Analysis ?
………………………
We’re Waiting……….

 

[j-c-c-62]

Obviously….. They Increase Structural Integrity!
Why Don’t YOU The Doubting Thomas Grace Us Lower Slobvovians With You’re Brilliance
By Submitting A Stress & Deformation Analysis ?
………………………
We’re Waiting……….

View attachment 1780824

View attachment 1780825

View attachment 1780827

But first, you need to share why with your expertise you do are not making the "stiffening" additions out of 1/2"? steel plate to further "Increase Structural Integrity"?

 

[gkent]

But first, you need to share why with your expertise you do are not making the "stiffening" additions out of 1/2"? steel plate to further "Increase Structural Integrity"?

That's just a totally ridiculous statement. Its like asking why the trusses in the roof of your house aren't made af steel instead of wood - the simple answer being "wood is sufficient" when all anticipated forces are applied.

But since you feel the need to be "right", let's just say you are so we can all get on with more important things !!

 

[j-c-c-62]

That's just a totally ridiculous statement. Its like asking why the trusses in the roof of your house aren't made af steel instead of wood - the simple answer being "wood is sufficient" when all anticipated forces are applied.

But since you feel the need to be "right", let's just say you are so we can all get on with more important things !!

But somehow the existing OEM LCA without "stiffeners" are not "sufficient"?

IMO it's important that modifications be made of the basis of reasoning, I accept others disagree with that thinking, and they can move on as they please.

 

[T2R9]

 

[threewood]

But somehow the existing OEM LCA without "stiffeners" are not "sufficient"?

IMO it's important that modifications be made of the basis of reasoning, I accept others disagree with that thinking, and they can move on as they please.

I've read a lot about LCAs getting sloppy around the torsion bar adjuster. Things get worn out. With a stiffening plate, is this less likely to occurr? I say it is. And no, I'm not going to scientifically test my theory. I'm just going to say it is without anything to back it up.