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Sub-Frame Connectors

1970GranCoupeCo

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I am considering installing sub frame connectors in my Barracuda convertible.

I do not plan on installing a high HP engine or drag slicks or anything extreme but I would like the body to be a little more stiff.

Does anyone have any recommendations of the kit to buy and any experience they would like to share?

THANKS!!!
 

Chryco Psycho

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I build my own , 1"x 2" .125 wall rectangular tubing , I cut a notch in the middle & reweld it so it follows the contour of the floor , I use a plate at the front to spread the load beside the T bar & cut the rear on an angle to match the front of the rear frame rails & weld it n , material cost is about $30 .
 

fasjac

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I used XV Motorsport on mine. They also contour the floor as well. If memory serves well, they were not that expensive.
 

1970GranCoupeCo

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I watched the US Car Tool video that they have on their home page Us Car Tool | Restorations, Unibody Stiffening, Body in White, Restoration Tools
and I was scared away because the people on the video appear to NOT know what they were doing. Yes I know the video was produced by Popular Hot Rodding but the mechanic in the video must be from Us Car Tool. The narrator guys says a bunch of time something like "It looks like we are doing to have to..." The car is on a "two post" lift with the engine and rear axel installed and with the car being suspended in the center the front end and the back end are sagging down and that is precisely what you are not to do...IF...you want your doors to close.

I do like the contouring sub frame connectors because they retain the stock look.

My convertible will sag and the doors will no longer close when it is on my two post lift so I would need to have the wheels holding the weight when I install the sub frame connectors.
 
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1970GranCoupeCo

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Thanks for posting the UTG video.

I do not not really agree with UT (no offence UT...peace out brother).

All of the advertising from the time they switched from full frame to unibody was that the unibody was stronger, stiffer, and quieter.

If the flexing loads from the unibody panels were to be transferred to the new sub frame connectors along the floorboards then the floor section spot rivets would have less work. The spot rivets and the floor panels aft of the leaf spring hangers will still have the same flexing.
 

Cratos

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looking into the comp engineering or mopar ones ( Bolt in) since the car is done and I am not going to pull the interior to do a full floor weld to the body
 

fasjac

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looking into the comp engineering or mopar ones ( Bolt in) since the car is done and I am not going to pull the interior to do a full floor weld to the body
That will work !!
 

1970GranCoupeCo

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I ordered the US Car Tool because I was going to replace the carpet anyway.

I will report back with the progress.
 

Coupe

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There is an episode of "Graveyard Cars" where Mark, argues against the need for subframe connector on convertible E Bodies. I don't know which episode but I'm sure you can find it on the Motortrend channel.
This link, is to a clip from the show.
 
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George72Cuda

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I installed Hotchkis frame stiffeners on my 1972 Cuda, purchased from YearOne.
 

Mopar Mitch

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I installed Hotchkis frame stiffeners on my 1972 Cuda, purchased from YearOne.
I like the Magnum Force TWIN-TUBE design... low-profile for decent ground clearance, strong 1-1/4" tubes, contoured bend for the floor of the e-bodies. I'm planning to install them probably this year.
 

70chall440

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Interesting comment from Uncle Tony's Garage



1. puff puff pass...
2. Id like to see his engineering degree...

built in flex.... they didn't tie the frames bc they didn't have to, they were not concerned with ultimate performance, they were concerned with getting the cars sold.

He can do whatever he wants to his cars, but I put sub frame connects in anything that has any HP and he is right it REALLY stiffens up the car.
 

70chall440

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There is an episode of "Graveyard Cars" where Mark, argues against the need for subframe connector on convertible E Bodies. I don't know which episode but I'm sure you can find it on the Motortrend channel.
This link, is to a clip from the show.

LOL you might want to think twice before believing anything that dude says.
 

1970GranCoupeCo

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Hmmmmmm... what is "bigger than a 440"?

What is an "angle iron"? He shows a U Channel and calls it an angle iron...everyone makes mistakes however this is a bit too many mistakes for such a short clip.

I own a factory convertible and it could definitely use some stiffening
 

70chall440

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He makes crap up as he goes, always has which is why I don't watch him; absolutely can't stand him not to mention the fact that he is an idiot.

I put SFC in pretty much everything I have and it makes a HUGE difference.

So according to these 2 geniuses the cars don't need SFCs and/or they have enough? If you have spent any amount of time actually building some of these cars you will see evidence of twisting and sagging (just look at the door gaps on many vintage Mopars); not that it is detrimental per se, but its there. Dipshit from GYC is completely wrong and just wanted to upstage the other dude and try and sound like he knows what he is talking about (which he doesn't).

As far as UTG goes, another "make crap up as you go" type guy. He is saying that the cars need to flex in order to keep the spot welds from work hardening...….. hmmm, ever flex a piece of metal back and forth for a while... it fatigues and fails (i.e. breaks). Sure a unibody car does absorb some of the energy through the body under acceleration, hard cornering, etc. but this is not a good thing or something I believe was intentionally built into the cars; it is a by product of the build design which evolved to reduce the time it took to build them and the cost of building (increase revenue). His hypothesis is that by adding SFC's it focuses all of the torque energy into one small area of the car... hmmm seems kind of like that would be desirable in about every scenario I can think of.

American cars have gotten a lot of crap for not being able to take corners and handle over the years and this is not without reason; in general most we never built to do that specifically and unibody construction did not help. If the question is whether or not to install SFCs, the is up to the owner but I install them in pretty much anything that I am going to put some HP into or want to handle.

Be careful of who you listen to and believe; both GYC and UTG are good examples of who not to listen to or at least to believe without collaborating information/evidence.
 

mayhem

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Not to bash GYC or UTG further but there are other car shows that yank the stock full bodied frames out from under almost every car they build & replace it with a stouter new frame or cobble in additional bracing/stiffeners to reduce flex. I'd rather have the SFC and not need them than to need them and not have them. Mopar to ya!
 
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