Any info on fabbed 2x3 rect. steel subframe connectors?

[BrianShaughnessy]

Job 1 on Sinnamon is to fix the wholey floors and add subframe connectors, torque boxes, and various other frame strengthing type stuff.

Am thinking of the 2x3 rectangle steel fabbed up cut thru the floorboards.   Who's done it / seen it / thought about it?

I know I won't be doing MP's (currently on Black Betty)  or ART (seen but no impressed ).    XV / USCartool are another option.

Discuss.

[Blown70]

1HotDaytona is doing XV, see the daytona thread they look nice, and I have seen here the US car tool look to me to be the best options.  And to me for that cost, I think I would use either XV or US.

JUST MY 

Tom

[BrianShaughnessy]

1HotDaytona is doing XV, see the daytona thread they look nice, and I have seen here the US car tool look to me to be the best options.  And to me for that cost, I think I would use either XV or US.

JUST MY 

Tom

I've seen the XV / USCARtools.  Nice... but read on the 1hotdaytona thread...

Brian, are those the US Car Tool subframe connectors?  They are a real clean looking design

Actually , they are XV Motorsports. I think the two are about the same though.

I gonna go against the grain a little on them, Im going to weld pieces in between on the top open side and the plug wel them to the floor in many places instead of the continuos weld. I just dont like the look of the weld on a painted underside. If it were getting undercoated Id be fine with it.

This means he plans on boxing them.   I might as well just put rectangular stock in and save that hassle.  The part about the mp's I like is I could jack on them.

[Blown70]

Ohh yes, I know he plans that but that is becasue he has the floors out... was not sure of your plan.....  sounds like the retangular stock maybe what is best for what your looking for.

Tom

[Mike DC]

 
I've cut a car's floors for rectangular connectors before, and I probably wouldn't do it again. 

It's not too horrible of a job to attempt but the whole thing just goes in a lot cleaner if you do it some other way.  There are not only the floorpan issues, but there is also the issue of merging the box tubing to the front of the rear subframe rail.  Once you decide to make the back end of the SC  more than 2" in height, this isn't gonna happen so easily like with the flat surface on the back of the tranny crossmember. 


I might use a homemade connector that includes two pieces of box tubing, though. Like use a 2x3 tube for the front portion of the subframe connector and then butt-weld that to a 2x2 square tube for when it passes under the lower area of the floor.  Fab up a bit of a diagonal transfer between the two heights, etc.   


---------------------------------------------


IMHO it's better to use moderate connectors in general.  The connectors are only useful to transfer the flex to somewhere else in the chassis.  Once the area between the stock front & rear subframes is no longer the "weakest link" then you're just adding weight to keep making it beefier. 


When the factory looked at the chassis & decided to add stiffening efforts to it, the area they chose wasn't the SC area - it was the torque boxes.

 

[Mike DC]

  

Oh, and BTW:  


In case you're looking at the factory floorpan and wondering about the odd bulges under the front seat buckets, and maybe wondering if it might work just as well to fab that area flat . . .  The floor bulges are there to facilitate sliding the torsion bars out the back of the tranny crossmember!  

[BrianShaughnessy]

Thanks for the info.

  I do like the look of what Doug's guy did in his operation hook thread.   Pretty nice.   I think that's what you're referencing when you mention a step down to 2x2 from the 2x3.  http://www.dodgecharger.com/forum/index.php/topic,41726.0.html

I don't want any peeing match about what's best or not.    There was some thread about FLC's car that seems to be missing today due to some opinions.   If it was a beauty contest then the XV/UScar stuff would win as it looks almost factory.
I want to restore and increase the ridigity of the unibody structure that's been compromised by rust repair and 40 years the best way and not necessarily the easiest.       

  Anyway I ordered some 11 guage 2x3 tubing. 

[Mike DC]

             
Yeah, that was just the kind of thing I was picturing with the height change. 


You could even make some flat tabs to weld those dual-height SC to the floorpans in a couple of isolated spots along the length of the connector.  It would still be biting off a lot less than trying to fit the laser-cut ones to every ripple of the factory floor.  (Example:  Tie those small front seat bracket stiffener thingys to the SCs.)