1968 Charger + subframe connectors questions

[HPP]

I got a question that might seem stupid but I haven't seen it asked before and haven't seen any in person to have any experience. If say the US sfc were welded at the ends but something like angle iron pieces were welded to the sfc sides along the length like brackets flush to the floor and bolted to the floor in appropriate spots, what would that effect be compared to welded all the way? Just thinking maybe it would keep it somewhat removable for later but give more rigidity than not welded at all.

That would provide additional support compared to not welding all the way. Some of the old Mopar units had bolts that went through the floor and into the connectors for this same purpose. IMO, the contoured units were made to make them more factory appearing, tie in the floor without cutting, and create a box section roof for the connector. However, typically a beam like these is no stronger than its smallest cross section area, which would be in the rear set foot well area, so tieing these into the floor is almost mandatory to create additional shear resistance to the small area. But, like I pointed out further above, until somebody lines identical cars up and tests every unit on the market, we won't have absolute data on their performance and they are much better than nothing.

But if you put connectors in , torque boxes are a must,
The two just work great together. 

They do compliment each other, but I wouldn't say they are a must have together and some subframe connectors are incompatible with torque boxes.  Torque boxes tie the subframes into the rocker panels, which could be viewed as a large longitudal connector.  IMO, every car should have at least one or the other but like Troy points out above, there are additional areas to consider as well.

[Nickrc3]

I was about to post the question on installing the US Car Tool contoured subframe connectors onto a vehicle which is currently disassembled.

I'm currently restoring my first-owned vehicle (a 68' Charger, 383/4-speed) and have the car completely disassembled, rolling on a body cart. In short time, my Bodyman and I will transfer it to the recently-purchased Auto-Twirler Body Cart Plus - http://www.autotwirler.us/product-p/bcp.htm, which supports the chassis at 8 points.

Since I cannot 'load' the suspension, I was concerned with welding the connectors onto the floorboards, however, I'm relieved knowing others have performed this practice as well.
Once the vehicle is supported, carefully leveled and secure w/ doors on, I'll then feel confident a twist will not be introduced by welding the connectors and torque boxes in.

Any additional comments on this process is greatly appreciated. Thanks Guys.

[Kern Dog]

I made my own set using 3x3 .120 wall boxed tube stock. Mine do not penetrate through the floor though. I took cardboard and made templates of the floor then traced the outline on the connectors. The parts cut away were then closed off by welding.

[Kern Dog]

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[Kern Dog]

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[Kern Dog]

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[Kern Dog]

The bare connectors looked sorta like these I made for my Brother in Laws 72 Duster.

[Kern Dog]

I also made torque boxes from 14 guage steel sheet metal.

[Kern Dog]

I used seam sealer where the connectors met the floor, then primed and painted it to look like the outer body.

[Steve P.]

All of them definitely help and welding in is the only way to really do it right, but in my opinion I think none of them look like the factory would have made them... I like the contoured to the floor as they look close to what should have been made from the factory, but if they would have been a factory connector they would have been flanged where it seats to the floor like every other part.  Maybe this is something for AMD and others to look into....

[Mike DC]

     
If the factory had done them, the floorpans themselves would have a smoothed-out flat shape above the SCs.  Gotta draw the line somewhere.

[Steve P.]

I don't know Mike. Sounds reasonable, but I believe the reason for all of the high/lows in the panels is for strength. Maybe you are right, but what I was getting at is the regular question of WHICH IS BETTER AND WHY. With all of the new stampings available today I think stamping sub-frame connectors with flanges is the way I would go. I also believe they would be much stronger than many of the connectors out there today. 

[MxRacer855]

$

Car looks amazing! 

[Kern Dog]

Thanks! I like the look of a painted underbody.

[MxRacer855]

Me too. It has an extremely clean look to it.

[gtx6970]

I made my own set using 3x3 .120 wall boxed tube stock. Mine do not penetrate through the floor though. I took cardboard and made templates of the floor then traced the outline on the connectors. The parts cut away were then closed off by welding.

Those look killer. Well done

I like the idea of seam sealling them to the floor,,,just in case they ever need / want to be removed .

I am going to look into this approach ,,soon

[Mike DC]

Seam welding isn't a bad idea but don't get too carried away with trying to make the whole thing airtight.  IMO it would be a better idea to do some "stitches" of attachment between the SC and the floor, and add some factory-style drain holes on the bottom of the connector.

[tan top]

I made my own set using 3x3 .120 wall boxed tube stock. Mine do not penetrate through the floor though. I took cardboard and made templates of the floor then traced the outline on the connectors. The parts cut away were then closed off by welding.

looks good !!  , nice work KD 

[Kern Dog]

Thanks guys.. I love this car!

"....and add some factory-style drain holes on the bottom of the connector..."
Great idea. I've thought of that after seeing a guy on Moparts do the same thing. His car really looked like a factory effort.

[don duick]

Great job Kerndog looks like a lot of hard work, Just wondering why you did not weld them to the floorpan?

[Kern Dog]

They are welded to the pan in a few spots but not in a continuous manner.