Subframe solutions (More about that)

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TrailBeast

TrailBeast

AKA Mopars4us on Youtube
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I have looked up the options and prices on them and was not impressed at all.
The structure of the materials just seems to weak and kinda cheesy actually for what they charge for the stuff.
I'm sure thier products make a difference, but not as solid as it could be.
ESPECIALLY for the "bolt in stuff" (come on, like that 14 gauge steel is going to support some bolts through it and stay tight?)
I don't think so.

Chk this out.

Sorry, I got interupted last night when I wanted to explain in more detail.

I started with 2 sections of 2x3 .085 boxed tubing.
When layed down flat the inside dimentions of the 3 inch tubing slides right over the original rear subframe section giving about 6 inches of weldable area both on the inside and outside of the installation area.
The tubes were completely closed in on the ends to seal them off to any moisture from the outside environment and also strenthen them from torsion effect.

The front of these are sealed by the peice of 2 1/2 angle and that lip from the angle steel extends under the crossframe section and gets welded in so that any load forward on them also gets transfered to the front subframe section instead of just to the back of the cross section wall.
The only part I had to move for this installation was the one bolted retainer bracket for the rear brake line, and I only had to remove the bolt and swing the retainer up out of the way.
No rerouting of lines or ebrake cabling was needed.

MAN, what a difference these made in the stability of the car.
Especially on uneven surfaces like bumpy streets and driveway entrances.
Also stopped about 95% of the interior creaks and groans form flexing the body.
After all the welding was done everything was sprayed with undercoat and sealed up.
 

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Those look great I was planning on making some this spring for my 71' dart. I was thinking of using .125 thick tubing is the .085 thick enough? Can you lift the car with a jack under the new frame tie without it bending?
 
dart0571 said:
Those look great I was planning on making some this spring for my 71' dart. I was thinking of using .125 thick tubing is the .085 thick enough? Can you lift the car with a jack under the new frame tie without it bending?
Click to expand...

That's what I was thinking , "Never as solid as it could be". One could make the a-body as stong as a tank with enough steel welded on.
Only a structral engineer might determine whats sufficient and whats overkill.
 
Especially if using square/rectangle tubing, I would use .125" wall. .083" is going to give more, and as mentioned, running over a speed bump or jacking up the car is going to give you issues as well.
 
dart0571 said:
Those look great I was planning on making some this spring for my 71' dart. I was thinking of using .125 thick tubing is the .085 thick enough? Can you lift the car with a jack under the new frame tie without it bending?
Click to expand...

.085 is 1/8 inch, and I don't think I would try to jack the car up using the center of the connector but towards one end or the other I wouldn,t hesitate at all.
They are right up against the floor pan pretty solid in a few places, but still.
Jacking it up in the center might bow them a little.


curleysracecars said:
Especially if using square/rectangle tubing, I would use .125" wall. .083" is going to give more, and as mentioned, running over a speed bump or jacking up the car is going to give you issues as well.
Click to expand...

I run my suspension kinda high anyway, so speedbumps are not even close to being an issue. (about 9 inches of clearance) plus they are hardly any lower than the original subframe sections (1/4 in lower in the front and about 1/2 in lower in the back.
I noticed that the left front fender does not try to lift as much from engine torque after they went in.
 
either way, nice job! any subframe connector style makes a big improvement in our cars. i like to make my own as well....id like to see more torque box installs as well...
 
Your'e right, it is.
Still way stronger than the aftermarket ones (Especially the bolt on's) and over .085 they start getting really heavy.
These are about 15 lbs each as it is.

ocdart said:
Actually, 1/8-inch is .125. You give away 32% of the tubing wall thickness by going down to .085" wall tubing.
Click to expand...
 
1/8" is .125 .085 would be between 5/64" and 3/32"

Some info that might be useful when considering material for connectors....
Weights for rectangular tubing:
3 x 2 x .083 = 2.699/ft
3 x 2 x .095 = 3.106/ft
3x 2 x .109 = 3.474/ft
3 x 2 x .120 = 3.90/ft
3 x 2 x .134 = 4/143/ft

standard sheet metal gauge thickness:
14 gauge = .0747
13 gauge = .0897
12 gauge = .1046
11 gauge = .1196
10 gauge = .1345
 
Thanks for the info I really like your design I'm planning on making mine the same way with maybe a bracket in the middle to attach to the front seat bolts or something.
 
Thats pretty much how I did mine.I tacked the rear floor boards to mine and you're right what a big differance in handling , also I think you did a damn good job
 
A couple of pounds is not going to make a difference......
 
After thinking about it I decided I wanted EVERYTHING welded only, so that bolt holes didn't get egged out or anything from any movement.
One of my big concernes was that they were closed at both ends so moisture didn't get inside them.

dart0571 said:
Thanks for the info I really like your design I'm planning on making mine the same way with maybe a bracket in the middle to attach to the front seat bolts or something.
Click to expand...
 
remember fellas its only as sound as what its welded to. It could be a 14" I beam, its still hanging from ma mopar's subframe. Can anyone put a mic. on that real quick?
 
That's the main reason for the tab that goes under the crossmember and is welded directly to the front framerail instead of just butting up tp the crossmember.


Dana said:
remember fellas its only as sound as what its welded to. It could be a 14" I beam, its still hanging from ma mopar's subframe. Can anyone put a mic. on that real quick?
Click to expand...
 
I have an idea on some subframe connectors for our cars. I will try to work on them late this week or next week. I feel there is BIG improvements to be made to stiffen these cars up. I'll start a thread once I get a piece mocked up.
 
I like it. I was going to do subframe connectors in a few weeks when I put the new motor and tranny in. I may use this, though I have heavier box tubing on hand.
 
I admire your handiwork! Im making my own connector's as well. to this purpose I stripped an old fridge of it's thick outer metal shell.I'll level up my work bench and make a hand built bender that can handle long length's of material and weld em in. Something else I consider important is torsion boxes. Welding them in really stiffens up a mopar.
 
I need a picture of these torsion boxes, or torque boxes as some call them. Im curious to see how and where they install.
 
No probably not,but I figure over kill is better. For the amount of weight being added (maybe a couple lb's) it's worth it anyways. It does also really help stiffen up the rear spring mount when adding rear torsion boxes.
 
It's an easy thing to produce if your interested. Be pretty cheap too. I'd sell em as a cheaper alternative to subframe connector's as they use the factory rocker panel's by tying into them.
 
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