Here are my US Car Tool welded in connectors. I fit the emergency cable. I would of made some changes for brake and fuel line install if I was to do it again.
Subframe Connectors and unibodies
- Thread starter Rusty knuckles
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Lefty71
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Im going to venture a guess that Pnora's frame connectors shown in post #101 above are probably stronger than both round and retangular versions by virtue of the continuous weld to the structural floor.... I would think this design is what the factory would have done, if they had deemed them necessary for street use, or at least folded over a flange so they could spot weld them in.
I closed up the ends and added a sleeved hole for the emergency brake cable:
(I cleaned up the weld after taking the above picture so it looks pretty
)
(I cleaned up the weld after taking the above picture so it looks pretty
)
your car is a 71? The underside looks a lot different than our 68-70 cars. Do you even need these added pieces? It looks like the stock floor already had subframe connectors built into the design? I'm just ignorant on this for your year car and just looking at your photos. After it's on the ground and driving, please let us know if you can feel the difference. I sure could on my 68.I closed up the ends and added a sleeved hole for the emergency brake cable:
View attachment 1654996
View attachment 1654994
View attachment 1654995
(I cleaned up the weld after taking the above picture so it looks pretty
It's a 68 Coronet. I probably don't need the subframe connectors since my current plan is to stroke the 400ci that the car came with) but wanted to play around a bit. And since I never actually drove the car before ripping into it, I won't have a before and after comparison (unless I can remember what my original 68 Coronet 500 felt like 45 years ago
)
Transformed mine. Rigidity on washboard streets, quieter, door closure. Dramatic.
Agree with Dennis. Night and day difference for my car even with non-aggressive driving.
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Average drivers don't own these cars. We are not the average people.
dfrazz
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I just added these 2” sq steel tubing to my ‘68 Charger. I’ve done this subframe on other b and e bodies and it is an inexpensive alternative that greatly improves the solid feel of the car. I actually cut into the cross-brace and rear subframe, slide the steel tube into both and then weld it in. IMO this is better than a bolt on or butt-welded subframe.
not so famous bob
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this is as far as I`m going to read this post , that's why I don't watch any of his videos , dumbest thing I`ve ever heard !
subframe conn. are one of the best things that can be done to a unibody . The more h.p. u have the more u need them !!!
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I lost all respect for uncle Tony and quit looking at his videos when he said how wonderful a pinion snubber was. His opinion on subframe connectors further strengthens my opinion.
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clicked on one of his videos someone posted here........... I lasted less than a minute...... not my uncle
68-500
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Im not calling anyone out. And I have no personal experience with SFCs. But it honestly surprises me that they make that much difference. Especially considering the willy-nilly way and placement the prefabricated ones attach to the torsion support.
I can see how the Birdsong method could really stiffen things up. Attached to the front and rear rails thru the torsion support.
I can see how the Birdsong method could really stiffen things up. Attached to the front and rear rails thru the torsion support.
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I don't see the CB method to add much, if anything. You'd have to test the various methods on a chassis table like XV Motorsports had some 20 years ago. It measured torsional resistance and allowed them to data-log it.
Yes, the rocker panels do act like a frame rail but they are spaced far enough apart to allow flex. The frame connectors when in line with the frame rails do add resistance to the corkscrew type of twisting these cars will do.
Have you noticed how little metal exists at the base of the A pillar of a steel roof car? That is not a lot of bracing to resist twisting.
I know that sometimes we make changes and we tell ourselves that the changes actually made a difference. Sometimes we are fooling ourselves because those changes resulted in no gains at all. Multi-electrode spark plugs, some cold air kits, MSD ignition kits, 110 octane gas, etc. Sometimes there is a difference so small, you need expensive equipment to test it to know for sure.
"Feel" is such a subjective thing. How do you prove that it feels different? You can't, it is just a sensation that can rarely be verified by a number.
I do know that my Charger felt more solid and quiet after I welded mine in in 2012. Back then, I still had KYB shocks that usually make cars ride harsh on rough roads if you have bigger torsion bars and stiffer leaf springs. I can't prove it but this car would rattle for a few seconds after hitting some rough patches of road. After the frame connectors, there was a momentary shake that stopped as soon as it started compared to the rattle that would resonate a few seconds on each road bump. Once I bought Bilstein shocks, it got even better.
Yes, the rocker panels do act like a frame rail but they are spaced far enough apart to allow flex. The frame connectors when in line with the frame rails do add resistance to the corkscrew type of twisting these cars will do.
Have you noticed how little metal exists at the base of the A pillar of a steel roof car? That is not a lot of bracing to resist twisting.
I know that sometimes we make changes and we tell ourselves that the changes actually made a difference. Sometimes we are fooling ourselves because those changes resulted in no gains at all. Multi-electrode spark plugs, some cold air kits, MSD ignition kits, 110 octane gas, etc. Sometimes there is a difference so small, you need expensive equipment to test it to know for sure.
"Feel" is such a subjective thing. How do you prove that it feels different? You can't, it is just a sensation that can rarely be verified by a number.
I do know that my Charger felt more solid and quiet after I welded mine in in 2012. Back then, I still had KYB shocks that usually make cars ride harsh on rough roads if you have bigger torsion bars and stiffer leaf springs. I can't prove it but this car would rattle for a few seconds after hitting some rough patches of road. After the frame connectors, there was a momentary shake that stopped as soon as it started compared to the rattle that would resonate a few seconds on each road bump. Once I bought Bilstein shocks, it got even better.
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I can bolt doors on a car with the USCT connectors while hanging on my rotisserie (connectors installed before rotisserie); and nothing changes when I take the car off of the rotisserie
68-500
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I agree its a very subjective subject! Im not denying you like the way they feel. Im just surprised that so many people say they make that much difference.
I can’t install them on my ride due to inference with the exhaust. So I may not ever know the difference. I have considered the convertible rocker reinforcements and torque boxes. But my stock 2 barrel 383 doesn’t necessate any stiffening.
I can’t install them on my ride due to inference with the exhaust. So I may not ever know the difference. I have considered the convertible rocker reinforcements and torque boxes. But my stock 2 barrel 383 doesn’t necessate any stiffening.
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If you are always driving a car mildly, even a high performance model, you probably won't see any benefit from reinforcements.
I agree, this is a modification for those that do push their cars beyond casual cruising.
I agree, this is a modification for those that do push their cars beyond casual cruising.
Dennis H can chime in here, but I recall he told me that shortly after he rebuilt his 440 prior to sub-frame connector install, he romped on the Go pedal and his windshield partially popped free. After adding SFC's, no such issue. Engine torque with these unibodies is another reason in addition to handling for adding SFC's.
I didn't even know this was a debate. Most agree the consensus is these cars greatly benefit from the addition of sub-frame connectors.
I didn't even know this was a debate. Most agree the consensus is these cars greatly benefit from the addition of sub-frame connectors.
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