Subframe Connector dilemma

-
73dust340

73dust340

Well-Known Member
Joined
Jan 31, 2009
Messages
112
Reaction score
0
Location
Pittsburgh, PA
Ok, I've been steadily fixing problems with my car and preparing it for Pittsburgh's humid weather. I will be sticking in a nice motor some day in the future (years from now). Now, I've read a lot of nice things about subframe connectors, but I'm not sure which type to get. I've got no problem welding them on, but for the time being I've only got a MIG with flux core wire, no gas, so it's a bit sloppy.

I've seen the kind that weld to the floors and the kind that go under them and don't weld to the floor. I'd like some input on which kind you guys think work best. I've seen some of you fabbed your own, but I don't have the tools or work area for that. I'm not too keen on welding to the floors, but if that's significantly better, that's what I'll do. I've got the tops of my floors all nice and stripped/painted and will be applying Damplifier sound deadener so If I must weld to the floor, now is the time. I'd like to skip subframe connectors for now and use the money on other things, but as I said, now is the time to weld if that kind of connector is much better.
 
I have a old set of bolt in frame connectors that I took out of my 67 Barracuda. $50 + Shipping
 
I'll get some tonight and get em posted.

Or........ I have enough steel left over to make a set of weld in connectors that you could bolt in as well but you would have to cut your floor. $125 + shipping

DSC00606.jpg


DSC00602.jpg


DSC00549.jpg


DSC00607.jpg


DSC00608.jpg
 
I like the idea of the form-fitting connectors from U.S. Car Body. From an engineering standpoint, they would seem to stiffen the body more than those that connect only the sub frames. Those are the ones I will be putting in.
 
I don't think I want to cut my floors for those, though they do look pretty strong. I'd weld the bolt on's anyway.
 
FISHBREATH said:
I like the idea of the form-fitting connectors from U.S. Car Body. From an engineering standpoint, they would seem to stiffen the body more than those that connect only the sub frames. Those are the ones I will be putting in.
Click to expand...

First you have to consider what sub frame connectors are designed to do. Handle the "beaming" loads that happen when we throw gobs of torque at these flimsy uni-body cars. Remember we are throwing considerable amounts of torque at the bodies, after 40 years of wheelspin, we have tremendous tires now, and all the energy that was spun out in wheelspin is now transfered back into the uni-body.
Welding a heavy gauge steel to an area on a car thats not designed to distribute the load isnt always a good idea. A floor pan is not capable of absorbing the energy, so its going to creat some serious stress cracks somewhere you least expect it.
IMO, weld in sub frame connectors that tie the front and rear subframes together are the best possible solution for these cars. Although the contoured ones "look" nice, "looks" dont dont help you maintain crontrol in 60 or 100 foot times.

:burnout:
 
autorustdave said:
First you have to consider what sub frame connectors are designed to do. Handle the "beaming" loads that happen when we throw gobs of torque at these flimsy uni-body cars. Remember we are throwing considerable amounts of torque at the bodies, after 40 years of wheelspin, we have tremendous tires now, and all the energy that was spun out in wheelspin is now transfered back into the uni-body.
Welding a heavy gauge steel to an area on a car thats not designed to distribute the load isnt always a good idea. A floor pan is not capable of absorbing the energy, so its going to creat some serious stress cracks somewhere you least expect it.
IMO, weld in sub frame connectors that tie the front and rear subframes together are the best possible solution for these cars. Although the contoured ones "look" nice, "looks" dont dont help you maintain crontrol in 60 or 100 foot times.

:burnout:
Click to expand...



The rest of the frame is made in the same way as the contoured connectors. Welding to the floor as well as both ends could only make it stronger.
 
For what's it's worth, I just bought these (see link) and am about to get them welded onto the underside of my floorpan.
http://zem9t.4pj3v.servertrust.com/ProductDetails.asp?ProductCode=USCT1M1105
They're light but strong and won't add too much weight to the Dart. The messy part is about to happen, which is getting the underside clean so that the welds will hold. I have to pull the carpet & seats, but I already have the new carpet ready to go in once the welding is finished. My plan is to clean off the underside, remove the interior, get the connectors welded on, then POR-15 the interior of the floor pan before installing the new carpet & seats.
Make sense? Wide open to suggestions.
 
Burntorange70 said:
The rest of the frame is made in the same way as the contoured connectors. Welding to the floor as well as both ends could only make it stronger.
Click to expand...


I understand that argument and can see why its seems like a no brainer, but it should really be looked at from an engineering point of view. You have to see how energy (large amounts of it, violently and in reverse during shifts) is transferred when put under load. If you do a 3 dimensional STAAD analysis, the floor is a poor choice for structural rigidity.

Anything helps under these cars, as long as its welded in place, not bolted.
Its all good !! :-D
 
is there any seat fitment issues with the ones you have to cut the floor?
 
I built the sub-frame connectors in my 73 dart sport . They look almost identical to the ones bigslim posted pics of . I had to cut the holes in the rear floor pans as well . To answer your question , the seats bolted strait in with no problems .
 
Here are the ones I am making for my 75 Duster. Went to the scrap yard and picked up the metal for $19.14 and the peices I got were 3 feet to long each. This is going to be a drag only car.

100_2365.jpg
 
welding in is the way to go. I like the ones burntornange70 was fabricating. Will do so with my ´69 dart.
 
The guy I bought my car from welded some in. He used
smaller square stock, looks like maybe 1-1/2" or 2" and it
fit well without cutting into the floor pans. Granted it's not
as rigid as bigger stock but they are much better than nothing.
 
Would it hurt or help to weld a connector in the rear between the frame connectors side to side?? I know you would have to go up and over the driveline and exhaust, but other than those issues, would it have any positive effects???
 
redness: If you can clear all the obstacles to doing something like that, yes it would help with rigidity.

The Mopar subframes suck. That is all.

Or wait, I mean they're AWESOME. I've got a new in box set I won't be using if you want them!

Steve
 
Here are the pics of my old bolt in connectors. Sorry it took so long to get em posted. I'm starting to get old and I get distracted easily!!!:-D

I don't remember who made them, I put them on my car new 25+ years ago drove it up and down the driveway a couple of times,put the car in the barn and forgot about it for 23 years. Decided to make my own weld ins so I pulled these out.

DSC00738.jpg


DSC00739.jpg


DSC00740.jpg
 
I have this attitude about mods on my car. I dont object to doing things I can undo just as easy. Therfore the bolt in connectors are right up my alley.
Ok I probably would add some little angle pieces on both sides welded to the floor every 16 inches or so. Still no perminate harm done.
What size tubing is that ? Thanks
 
One thing that hasent been mentioned is whats your intended abuse plans for the car is directly praportional to the need for heavy duty conectors. 4spd auto strip street
 
You must log in or register to reply here.
-

Back
Top