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  #31  
Old 12-06-2004, 01:46 PM
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Quote:
Originally Posted by dwc43
Well show me the ones that don't exist on my Duster with the 4 spd or the '70 Challenger 4spd car that I sold to Mike a few years ago. Both are low mile original cars without any torque boxes.

I did say "most", not "all".

Seems Ma' Mopar was really inconsistent on this.

I to have seen 4-speed a-bodies with and without factory torque boxes. Not sure what Ma' Mopars intent or consistency was on this at all.
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  #32  
Old 12-06-2004, 03:01 PM
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I like the Comp Engineering bolt in SFCs although I weld them in. I also drill them everywhere they touch the floor pan and weld them to the pan then weld my drill hole shut. They are small tube size but the only thing I can see SFCs do, is transfer forward kinetic energy to the front sub frame to keep the body from having to absorb it and potentially warp it out of shape.

As long as they are straight they will work as good as 4"x4"x3/8". I have launched very hard with my setup so many times I can't begin to guess. They show absolutely no signs of flexing. Because they are kept straight by my welding them to the pan. I am putting a set on my 74 Challenger the same way and don't expect any trouble... and that's with 700+ hp and 725+ torque.

I will be putting torque boxes on the Challenger but that is for a different issue all together. As talked about earlier.

My understanding of this subject is this (and I might be wrong but this is how I read it).... SFC's serve a totally different issue than torque boxes... SFCs give the forward kinetic energy from the rear sub frame a different route to the front sub frame... of course some still passes through the body panels. The amount of body flex from forward energy is lessened dramatically.... but torsional flex is caused by the engine trying to tip the car over. So torque boxes are added to help the torsional energy to be transferred to the rear of the car... so you can see this is 2 totally different areas of energy transfer.

If this is wrong.. Please enlighten me...
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  #33  
Old 12-06-2004, 03:24 PM
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Fast Eddie;

I have read somewhere that the torque boxes where put on A-bodies with a certain option set. I don't know right off the bat which options where needed; but just because it was a 4-speed car didn't mean you automaticly got torque boxes. So you are correct..as you stated earlier.

I had a 70 Dart 340 4bbl 4sp 8.75 sg that had them. My buddy had the same car with peg leg without them, but I'm not sure of all the other options that added them (or not).

It seems Ma Mopar put more weight on needing them in certain cases than others. Accually more weight on needing torque boxes than SFCs so; are they worth it??? Mopar engineers must have thought so...
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  #34  
Old 12-07-2004, 11:08 AM
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Quote:
Originally Posted by bigiron
My understanding of this subject is this (and I might be wrong but this is how I read it).... SFC's serve a totally different issue than torque boxes... SFCs give the forward kinetic energy from the rear sub frame a different route to the front sub frame... of course some still passes through the body panels. The amount of body flex from forward energy is lessened dramatically.... but torsional flex is caused by the engine trying to tip the car over. So torque boxes are added to help the torsional energy to be transferred to the rear of the car... so you can see this is 2 totally different areas of energy transfer.

If this is wrong.. Please enlighten me...
I think you are correct.

Like I stated before, SFC's do nothing for torsional (twisting) stress, they do however serve best for compression and beaming forces (as you stated).

TQB's on the other hand, do nothing for compression and beaming, but do wonders for strengthening torsional stiffness.

IMO, the best thing to do for your Mopar is to add BOTH if you don't have them at all. Then you've done everything you can to solidify the body (short of installing a 6-8 point roll cage).
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  #35  
Old 12-07-2004, 08:59 PM
doungta1@aol doungta1@aol is offline
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Quote:
Originally Posted by Fast_Eddie
They were NOT just on Hemi and convertible cars. They were also on all cop cars, taxi cars, and most 4-speed performance models (both small and big block).

dw3,

Perform the simple test I suggested with a wood frame before you determine whether they are worth the work or not. Corner gusseting DOES add strength, and this is basically what torque boxes do.

SFC's do little to nothing at all in terms of increasing torsional strength in a unibody car.

And installing torque boxes is about as difficult as installing SFC's.

If you don't believe me dw3, I could show you some pictures of a '72 Demon 340 4-speed car that came from the factory with torque boxes.



Fast Eddie - My subframes are tied with channel and I have 8 point row bar. Car is extremely solid - any rust that may have been on the car has been removed (virgina car) - Car will be 95 percent driven at the track and maybe a few miles during the week to hit the local car hop ( have a spool so not street driving will not be practical). Will these torque boxes be of any value to my application? Reading these post have been quite an education for me.
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  #36  
Old 12-08-2004, 10:22 AM
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Quote:
Originally Posted by doungta1@aol
Will these torque boxes be of any value to my application? Reading these post have been quite an education for me.
Would be a waste of time, money and effort in your case.
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  #37  
Old 02-12-2006, 01:04 PM
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Exclamation

In case anyone is interested, the torque boxes that are made by Auto Rust Technicians are NOT factory reproductions. They are made out of heavier gauge metal and are stamped differently than the stock units.

If you are looking for factory reproductions, check out the ones made by Scott Smith over at Harms Auto. These are exact factory reproductions and very, very nicely done.

The A-Body ubits are not done yet, they are waiting on the final tooling. They should be ready sometime this coming summer.

Again, these are accurate restoration parts, not aftermarket reinforcements.

Enjoy!

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  #38  
Old 02-12-2006, 05:53 PM
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Has anyone tried these?...http://www.uscartool.com/Bframeconn/index.html
The design seems pretty slick to me, what do you guys think?
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  #39  
Old 02-12-2006, 06:45 PM
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Quote:
Originally Posted by superbee1970440
Has anyone tried these?...http://www.uscartool.com/Bframeconn/index.html
The design seems pretty slick to me, what do you guys think?
Those are very well done as well. Just put a set of these on a friends Road Runner. Looked about as factory as you can get.

Very good quality.

A-Body units should be available by spring they say.
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  #40  
Old 02-12-2006, 07:02 PM
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Quote:
Originally Posted by Fast_Eddie
Those are very well done as well. Just put a set of these on a friends Road Runner. Looked about as factory as you can get.

Very good quality.

A-Body units should be available by spring they say.

What variety would you consider to be "the best"?
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  #41  
Old 02-16-2006, 09:58 PM
70Beee 70Beee is offline
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I've owned a '72 Duster 340 4-speed since 1975 and it has the torque boxes. But from the cracks found in the floor pan during a restoration, it needs sub frame connectors as well to stop the chassis from twisting too much.
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