DIY Frame Connectors

[PLUM_72]

I am planning to do a frame connector project on my 72 Challenger.  The route I was going to go with is the 2x3 tube and cut the floors.  My car has done since the 90's.  I thought if I cut the floors much of the welding could be done through the top side.  Weld the tube completely to the floor from the top, with a few tacks and some seam sealer along the bottom.  This would minimize what I had to weld underneath.  Obviously there is some welding to the cross member and a bit to the rear frame.

Anyone have pictures or tips of your experiences with this type of connector?  While US Car Tool type is nice, I cant see doing this type on my back while the car is sitting on ramps.

I know this topic has been discussed a lot in the past.  I have looked through past posts however, many of the pictures associated with these past posts are now gone.

Thanks in advance!

[burdar]

I read your post on Moparts.  Lots of people responding there.  I will just mention that the MP or Mancini bolt-in frame connectors usually block the E-brake cable hole.  You'll have re-drill the hole up higher on the x-member  to clear the mounting plate.  Also, most bolt-on style connectors won't clear factory torque boxes.  Being your car is a 72, you probably don't have to worry about that.

I've been reading a lot of posts about this because I need to do something with my latest project.  I'm leaning towards 1.5 x 3" rectangular tubing.  It should clear the floor and can be notched around the rear frame.  Instead of welding a large plate to the outside of the torsion bar x-member, you could cut the hole and run the connector into the x-member...then weld the perimeter.  You might not have to mess with the e-brake cable that way.

[Mopar Mitch]

I'm also planning eventual SFCs.. but no cutting of the floor... maybe the twin-tubular design from Magnum Force Racing.. has low ground clearance, perhaps strong with the total of the twin-tubes...   another 1-2 years away at this time.

[70chall440]

I have the US car tool SFC on my cuda and some homemade ones on my challenger, the US car tool ones look better for sure but require a lot of fitting and welding. My homemade ones probably are not as strong but they are pretty low profile, however they are welded to the floors as well. I had to make a notch for the E brake cable. 

[JoeGrapes]

I've been looking at frame connectors for a few years now. I have the same problem with the underside being finished and painted. If I were doing a car from scratch I would go with the US Car Tool ones. The Hotchkiss ones look nice but hang down to much for my tastes. I keep looking at the Magnum Force connectors but just can't seem to find any real world info on them from anyone who has them. I even contacted Magnum Force but of coarse they said they work great. I do like the US Car Tool front end braces. They can be installed buy just taking the fenders off so all the welding will be covered up once the fenders are bolted back on. Nice YouTube video on how well they work.

[70chall440]

You could install the US car tool braces without welding to the floor; if you take time to get a nice tight fit against the floor (they do require a little trimming) and then just weld the front and back, you would get most of the benefits of a SFC. There are numerous designs out there that only weld to those 2 areas and do not even touch the floor. Welding to the floor just looks better and does add strength but on a normal street car you wouldn't realize that amount of strength, plus I think it is arguable how much it would/does add.

[shawge]

Something like the A.R.T or the old DC braces don't require floor welding.