https://youtu.be/Nwes-SP8u4w


https://youtu.be/xYkQSI-2NRw



https://youtu.be/f2Op00pO6Kw

Good informative videos.


Greg

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http://www.youtube.com/hyperpack

Just to keep it fair and balanced, I have voiced my doubts on mopar LCA gusset reinforcement for more the a decade many times on many forums, stemming mainly from a normal engineering aspect, and adhering when possible to the KISS principle, and any solution should be based on choosing the best solution to solve a specific identifiable problem, in advance..

Problem here always is when asking this question, nobody can identify the specific problem they find the need to solve, or why this is the best solution for whatever they are attempting. Normal and typical lame response usually boils down to, "It can't hurt", well if that is enough you, make your gusset out of 3/8" steel plate, "it Can't hurt".

Fire up your welders.

And I don't question the the videos author's motive or sincerity, and I only reviewed the first video.

I wonder if Bob Tullius' Trans Am Group 44 Dart had braced LCAs?

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“Buy the ticket, take the ride.”
― Hunter S. Thompson

I was posting those videos as an informative way to learn about pressing in and out the LCA bushings and also how to correct the Slop at the LCA pivot; personally, I bypassed all the boxing plate stuff.

I am not sure that there's any proof as to wether the LCA gussets work or not. But That's for Mopar mythbusters to find out with a car setup on the track or skidpad with lots of measuring equip and 2 sets of LCA's - one boxed and one unboxed with new bushings etc.

I think for all but the most crazy track day or autoX cars those pieces are probably a sham.



Greg

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http://www.youtube.com/hyperpack

I wouldn't go as far as calling it a sham. As mentioned above, it can't hurt. The only bent or maligned LCA's I have ever seen were the result of an accident. I don't think it is worth the extra weight, particularly on a drag car (in my case). I'd like to know how to make them (safely) lighter, if that is even possible.
Also, replacing that LCA bushing is a pain, even with a press.

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-MattMan
LEANED & MEAN

I don't think the control arm itself is all that heavy? And I don't really think there is any way to "safely" lighten it much. Don't forget when your wheels leave the ground, and when you are stopping the control arm is pretty important! You could install aluminum strut rods? Not sure if there is much weight savings there?

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

I wonder if the tubular ones are maybe a bit lighter?


Greg

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http://www.youtube.com/hyperpack

The 65 Belvedere LCA weighs 10 lbs. There isn't really any 'fat' on them. I think the best lightening ever would only bring them down to about 9 - 9 1/2 pounds. I believe that the tubular LCAs available weigh more than the factory ones. The 65 Belvedere strut rods weigh 3.2 lbs each.
Plenty of other places to find weight reductions. I also think the OE lower control arms are strong enough as-is, at least for my applications.

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-MattMan
LEANED & MEAN

Lower Control Arms
QA1 offers Mopar A, B and E-Body control arms with sway bar tabs. These lower control arms are a direct bolt-in on your factory k-member and are twice as strong as factory arms and don't add any weight. The set includes bushings, pivot arms and nuts for ease of installation. Made in the USA.

I have the QA1 upper control arms and "Boxed" lower control arms. The one advantage I noticed was while replacing LCA bushings, the boxing made a much stiffer(ridged) feel when pressing out and back in.

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1964 Dart GT

I liked the videos.

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“Buy the ticket, take the ride.”
― Hunter S. Thompson

Understand, the LCA mainly sees two in use forces, the lever arm on the TB, and any lateral forces the tire imparts in cornering. It sees a slight amount of force in braking, because those forces are mainly controlled by the lower diagonal brake strut. The brake forces are limited by the tire contact patch traction ability, ie its limited. Other unpredictable forces are from curbs, potholes, other cars etc that are unlimited in number and force.

The brake strut when loaded in effect, drives the K member end of the LCA forward, ie why it doesn't require any real location methods. since the wheel contact patch is closer to the brake strut interface, then the hex end of the LCA, the bending forces are reduced. Regardless, these style/design LCA's are used on a very wide range of Mopars in weight and power, for decades, and IMO, unless you are running 80 TW 355 front radial slicks, with Aero DF, at triple digit speeds, you are not bending/distorting your OEM LCA with braking.


And regarding the TB lever arm, understand the TB is intended to twist, ie its a spring, every application has a spring rate ideal window, nobody is running 3"? Dia TB, the LCA is mainly along for the ride so to speak. I challenge anybody to measure any lever beam bending in a LCA with a TB of any size ( which basically means there are now two springs in series in the suspension system, if its measurable at all), that cannot be dialed out by simply upgrading TB dia. A sway bar is also basically a spring also, limited forces involved relative to the LCA. . A shock adds to this but mainly from a suspension velocity aspect. and suspect the shock can also be optimized for the rest of the suspension system, perceived warts and all.

I've changed my mind on aftermarket alum strut rods. I don't believe they are built with 2024 or 7075 alum, the only two maybe acceptable for the application. Main issue is fatigue, ALL alum fatigues over time under repetitive loads . The alum strut rods are the same size as OEM, so no real boost in tensile strength. If one fails, hope you added air bags while you were at it.

Hmmm, I had to check the top of the browser to be sure that I hadn't stumbled into a Bimmer or Porsche site. The above post reminds me of the engineer types that debate arcane pointless topics to death. Which seem to infect those sites.

The only thing they may do is strength the LCA were the rivets hold the lower ball joint bracket and stabilize the mount point for the bushing. I am sure some racer somewhere broke the LCA and this was a fix that has propagated thru the years.

I have not strengthened mine in hard handling applications. Maybe I'll add a few small gussets someday. I did try the QA1 tubular LCAs, which I believe are made by (or copied from) CAPautoproducts. They were 1.5-2 lbs/side lighter rather than the claimed 4 lbs. I'll not do that again. Also, I saw a set of them bent to hell on a Valiant road course car in Aussie in 2014. They went back to stockers.

Lou

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Home of Slant6-powered fun machines since 1988

"Arcane" might be a little harsh, but i got my big boy pants on today.

However "arcane" is appropriate IMO concerning the merit of adding LCA gussets in the first place, and it repeatedly gets brought up without any sound justification, and best countered with a simple discussion of what is at play on the matter in the first place. Thought I made a reasonable stab at that objective.

Its lifespan is right up there with the verboten tactic of charging a battery sitting on bare concrete.

Lightening lower control arms always scared me. I used to see a guy with a 9 second big block Camaro carry the wheels out past the tree, and he had hole sawed the lowers and uppers. I never understood how he made it through tech.

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Official Cookie and Mater Tormentor.