Discussion in 'Suspension, Steering and Chassis' started by Shorty Thompson, Apr 22, 2018.
Who got the best place to get some from ?
In my opinion there are only 2 real good ways to do them. Build them and weld them in, or get the ones that weld into the floor. A google search show craploads of designs and prices, mopar a body subframe connectors - Google Search
US Tools has a great set and all the stuff to stiffen up the frame
US car tool, awesome fit and quality have done 2 sets already, they make good stuff 67-75 Mopar A Body Frame Connectors
OP probably already knows, but they are not a "fit and weld first time" deal. If you do it yourself, be prepared to do some trimming to meet the contour of the floor pans and install them multiple times. Worth it, though.
Looking at every post . Thank you so much
I was talking about the home made type that don't weld to the floor OR the prefabbed ones that do. My Brother and I made mine with .085 wall 2x3 box steel that are not welded to the floor. The 1x little baby bolt in type I don't care for. Here's what we did that cost about 50 bucks and took a couple of hours.
I welded the US Car Tools kit in my Dart. You can certainly home build your own, but you won't find many much better than what US Car Tool sells.
Has anyone tried to measure the improvement from subframe connectors? I get that intuitively, thicker tubes and designs that follow the floor would be stronger but how do we know if lighter pieces might not do the job well enough?
How light? We're not talking about much weight here, at worst 10-12' of 2x3 steel... With more precise fitment and full welding the material could be lighter. I slit my floors open to run the 2x3 from t-bar crossmember back stuffed into the rear frame rail as far as it would go. Fully welded in everywhere.
carpet layed down nice over them
Beware that the US Car Tool require re-routing the brake and fuel lines and the park brake cable. Been working on a 1970 Charger that already had the connectors in, but none of the other parts. It's a real PITA...
You’d literally need a full finite element analysis of the chassis and different connectors to figure that out. Comparing different installs on different 50 year old cars wouldn’t likely get you good information. Just a really large margin of error. With the connectors something is better than nothing. Even the bolt in Mopar Performance connectors, welded in, make a difference. Eventually you reach a point where adding more wall thickness or tube diameter doesn’t matter, you’ve strengthened the chassis as much as you can with that single reinforcement. I think the weld to floor US Cartool connectors probably look best, but they’re a royal pain to get fitted and fully welded to the floor if you’re not working on a media blasted chassis on a rotisserie. And you have to re-route all the lines. I used 1.5x3 tube with large landing plates on my Duster. They work great, fit flat to the floor and frame, and were a lot easier to install than the US Cartool connectors I installed on my Dart.
I disagree. I've done US Car Tool stiffeners both ways rotisserie and on a hoist. The only trouble is getting undercoating off or not knowing how to remove it. Other than that it's just welding. The trouble area on sub frame connectors is not placing the weld on the US Car Tool sub frame connector and rolling the weld into the floor pan. Once you learn that, it's easy. Just takes time and a good welding jacket.
I believe that you don't see this as a big deal...but (correct me if I'm wrong here) the trimming and adjusting to get these to fit perfectly along the floor pan then prepping/welding the entirety of the length is orders of magnitude more troublesome than bolt-in/weld-in options. It certainly doesn't sound like rocket surgery but doing it right is time consuming and daunting to people who don't have welding experience, proper working space, extra time, etc. Are these better? Most people seem to think so! They certainly look way better. Is the level of improvement over more accessible options proportional to the additional effort/expense? That's not a forgone conclusion, IMO. If anyone wants to offer up their Mopar for me to practice on, come on over!
Removing the undercoating is probably the easiest part of the whole deal. The USCT subframe connectors take a lot longer to install, and the welding is not easy, at least not in my opinion. I've been welding for over 25 years. I wouldn't consider myself an expert by any means, but I didn't pick up a torch yesterday. The welding that needs to be done definitely isn't the hardest I've done, but it's not something I would consider "easy" for an amateur welder. And there's a ton of it- you're conservatively talking about at least 15 linear feet of weld bead to fully weld them (at least on a 111" wheelbase car). And if you're working off of jackstands, it is a pain in the ass IMHO. Not everyone has a hoist, and not everyone is stripping their car and putting it on a rotisserie. I've installed both types of frame connectors, and installing the tube style connectors is MUCH easier. Done in a few hours, no line re-routing, and depending on the size of the tube and landing plates very little undercoating removal. I like the US Cartool connectors, they look a lot closer to factory and they're well made parts. But there is a big difference in the time and skill needed to install them compared to the tubular style connectors. I've done both, and after installing the USCT connectors on my Dart in my garage with the car up on 12 ton jackstands it's still my opinion that it was a pain in the ass, especially compared to a similar install of the tubular connectors on my Duster. That doesn't mean they aren't a good part, or that they shouldn't be used. It just means that a person should consider their skills and resources available when deciding what kind of connector they're going to install. Exactly. They have their pros and cons. They do look better IMO, but they require a lot more time and work to install. Even the brake and fuel line re-routing is not something to just blow off, it takes some time to do it right and have it look good. And whether or not they actually work better is not something that anyone here can know for sure, absent of some really complicated finite element analysis that no one is going to do.
I just bought 1.5x3 .125 rectangular tubing to make a set for my 68 Dodge Dart. I appreciate you posting the diagram as I'm doing a similar design. I am curious though, was your car a Dart Sport aka Demon? Unless the 73 Dart coupe body style really shortened up the underside my 2 door 68 Dart coupe (not a post car) needed 50 inch long pieces not 40~ inches.
Dart Swinger hard top here.
Convertibles and Big Block cars with the 4 torque boxes.....This is a little trickier at the rear to attach the frame connector. The US tool item works, but not what I want. I am looking at Chrome Molly round tubing, slight bend to follow the floor and incorporate the driveshaft loop. This is for my 69 Dart Convertible. Convertibles really benefit from the frame connectors. I figure round tubes place just right will allow emergency brake routing better.... any thoughts, anyone tried?
Most round tube connector are doubble tubes so the second tube keeps the single tube from twisting.
Applause . applause , applause!!!! Very good replies folks. I'm no stranger to a mig welder. I own a 160 Century, 220v.. I also have many years welding lawn cart cart bodies as well. Meaning 16ga. , to 19ga. . So I'm no stranger to thin metal. Keep the comments coming ! I am very anxious to hear everyone's opinion.
I ordered 51 inches which means about 6 1/2 inches will slide over the rear rear and the front it will but up against the torsion bar mount. I don't see how there is any possible way yours would be long enough at 40 3/4 inches total length. That doesn't even come close to being long enough. I wondered if you actually meant to type 50 3/4 instead of 40 3/4 on your diagram?
Do not use the measurements in the image above as they are 10 inches short. Sorry for the mistake, and this image is correct.
Yeah my best guess is it must have been a typo because I think our cars unibody should be identical (2 door coupe Darts). I just would hate for someone to see that diagram and order based off the measurements if they are wrong lol. I almost did but thankfully I thought I better go measure mine just to be safe and that's why I ended up ordering 51 inches instead of 41 .
And you were correct, as I typed 40 3/4 when it should have been 50 3/4. Thanks for pointing that out so it could get fixed.
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