Torque Boxes and other stiffeners

Posted By: mopardamo

Torque Boxes and other stiffeners - 11/11/12 08:02 PM

What is your opinion about the available chassis stiffeners on the market? Who has the best components? And what components are best ignoring any particular sanctioning body rules to get a super stiff E body? Yea I know that a multi-point cage is the cat's meow but its going to be a street driven piece in the end. Debating on a hoop behind the front seats and a drivers bar that swings out but definitely no more than that on a cage. Thoughts?

Damon

Posted By: amxautox

Re: Torque Boxes and other stiffeners - 11/11/12 08:10 PM

What will be the basic purpose of the car? What else do you plan on using the car for?

Posted By: mopardamo

Re: Torque Boxes and other stiffeners - 11/11/12 08:28 PM

Intend to have a multipurpose car. Already plan on welding the critical seams, add inner fender braces, radiator lower brace, sub frame connector and torque boxes. Want as stiff a system as I can get before potentially adding the hoop and drivers side brace. My thinking is the stiffer the better for anything. I'm the kind of person that put custom valved Fox 2.0 shocks on a basically stock Ram for added control. Well not exactly stock. Asking to try and get an handle on who's individual bracing components are best and am if I am missing something I should be doing while the care is getting the welding done.

Damon

Posted By: jcc

Re: Torque Boxes and other stiffeners - 11/11/12 08:39 PM

A roll bar by itself will add very little stiffness. Torque boxes AND subframme connectors are both doing the same task. IMO, taking into account your restrictions, forget the torque boxes and engineer in say a welded massive 4" Vertical by 3" horizontal .083wall frame connector attached to the most optimum points, and call it a day.

Posted By: cudazappa

Re: Torque Boxes and other stiffeners - 11/11/12 10:18 PM

Quote:

Intend to have a multipurpose car. Already plan on welding the critical seams, add inner fender braces, radiator lower brace, sub frame connector and torque boxes. Want as stiff a system as I can get before potentially adding the hoop and drivers side brace. My thinking is the stiffer the better for anything. I'm the kind of person that put custom valved Fox 2.0 shocks on a basically stock Ram for added control. Well not exactly stock. Asking to try and get an handle on who's individual bracing components are best and am if I am missing something I should be doing while the care is getting the welding done.

Damon

Stitch welding is a great starting point. I've seen where stress cracks form in rear quarters by the rear glass (well on a Camaro raced hard, but not too far from an E-body... LOL)

Start with the subframe connectors. Two ways to go on this. Use the hotchkis ones (that tie to the rear spring mounts) or the fabricate your own (2x2 or 2 wide x 3 tall, I like 1/8 wall) from the rear frame rails (both will weld to the t-bar x-member). The hotchkis ones will essentially nullify a rear torque box. If you go the fab your own route, you could get your rear torque boxes from auto rust technicians.
Front torque boxes are good for tieing your front frame rails to your t-bar x-member. The front of your e-body is really flexible.

So now I'll concentrate on the front. The under radiator brace is a great idea, as well as the shock tower supports. Some people love the monte-carlo bar above the engine. XV has all this stuff, but if you have fab skills, nothing too bad I would say.

Finally the roll bar. Equalize the stiffness and put a passenger door bar in. The real stiffening portion of the roll bar will be the rear down tubes. This will stiffen up your frame where the leafs reside. Also gives you a great place for your safety harness

Eagerly waiting for my house to be built so I can do all this to my 71 Challenger! SOON!!! (well, the roll bar is on next off-season's list) I have added the 2x2 frame connectors (auto rust technicians) already and that was a tremendous improvement.

Posted By: AndyF

Re: Torque Boxes and other stiffeners - 11/11/12 10:20 PM

XV did the most work on the subject that I know of. They are the only people that ever put a muscle car on a four post and and showed the video. Look over their stuff as much as possible and see if you can figure it out.

I also covered the topic in my B-body book. Look over the pictures and see what you can pick out.

Without some measurement equipment it is all guess work, but if you copy the stuff that people did correctly you'll get close.

Posted By: dangina

Re: Torque Boxes and other stiffeners - 11/12/12 02:52 AM

i didn't want a cage in the car but i did everything else:

stich weld the car,
subframe connectors,
torque boxes,
inner fender braces,
lower rad brace,
welded up the shock towers,
will be building a engine brace as well...

Posted By: mopardamo

Re: Torque Boxes and other stiffeners - 11/13/12 03:47 AM

Hello jcc,

Guess I did not realize that torque boxes aren't needed once I put in the subframe connectors.

Looks like VX has quit making the shock tower brace. Anyone else make these?

Damon

Posted By: ChrisUSCT

Re: Torque Boxes and other stiffeners - 11/13/12 04:29 AM

We have just come out with our new inner fender braces for the E-Body Mopars. Check out our online store for some pics www.store.uscartool.com. We have this video where we tested the stiffness of our inner fender braces. We also have frame connectors, torque boxes and core support braces for the E-Body's. Heres the link to the video: US Car Tool E-Body Stiff Test

Posted By: jcc

Re: Torque Boxes and other stiffeners - 11/13/12 05:17 AM

Quote:

Hello jcc,

Guess I did not realize that torque boxes aren't needed once I put in the subframe connectors.

Damon

Well that is my take on the matter, torque boxes were an OEM bandaid, and subframe connectors are the correct solution, having both does not cause any significant issues and they still add additional stiffness, but again IMO not much for what it is, and a well designed robust subframe connector is best, in lieu of a full cage.

Posted By: Mopar Mitch

Re: Torque Boxes and other stiffeners - 11/13/12 06:39 AM

I'll agree with the XV and US-Tool-Works products as they've done some interesting studies... shown in their videos. I like the SFC that become welded across the floor pan, but with certain club "rules", that type is not allowed (too bad!).

Posted By: Skeptic

Re: Torque Boxes and other stiffeners - 11/13/12 11:50 PM

Quote:

I'll agree with the XV and US-Tool-Works products as they've done some interesting studies... shown in their videos. I like the SFC that become welded across the floor pan, but with certain club "rules", that type is not allowed (too bad!).

Any reasons that you know of why that is disallowed? It's not that expensive, and our old uni bodies weren't stitched together all that tightly to begin with.

Posted By: cudazappa

Re: Torque Boxes and other stiffeners - 11/14/12 02:35 AM

Quote:

Quote:

I'll agree with the XV and US-Tool-Works products as they've done some interesting studies... shown in their videos. I like the SFC that become welded across the floor pan, but with certain club "rules", that type is not allowed (too bad!).

Any reasons that you know of why that is disallowed? It's not that expensive, and our old uni bodies weren't stitched together all that tightly to begin with.

Mitch is talking about the SCCA (and all the clubs that use their rule-set). They have to make a broad set of rules to define their classes that can satisfy everything from a mini-cooper to a Lamborgini.

Its a rather recent addition to the street prepared rules (one level up from stock) to allow frame connectors that's been modified from bolt in, to weld in, to now 2+1 points of attachment (straight, the +1 allowment is because, I believe, of Fox Body Mustangs having their seat mounts being into the connectors). Its an evolution of rules. If you want to change the rules, get a group of guys together and present a convincing argument to the rules committee to get a change.

In defense of the current rules, 2x2 tubing underneath the floor is still stronger torsionally than the contour of the floor style (thicker wall, and larger overall cross-sectional area). I tucked mine up to the floor (I'm now beyond 2 pts of attachment) so I moved up 2 classes.

Glad to see US Car Tool stepped up to the plate with the kit.

Posted By: TC@HP2

Re: Torque Boxes and other stiffeners - 11/14/12 03:41 PM

Quote:

Hello jcc,

Guess I did not realize that torque boxes aren't needed once I put in the subframe connectors.

Damon

The role of the torque boxes is to better tie in the subframe structure to the rocker sill. Rockers provide a similar beaming resistance as a subframe connector, but they are not as stout as a dedicated subframe tie. The Mopar Chassis book actually recommends beefing up the sill plate in dedicated track cars.

Quote:

Quote:

I'll agree with the XV and US-Tool-Works products as they've done some interesting studies... shown in their videos. I like the SFC that become welded across the floor pan, but with certain club "rules", that type is not allowed (too bad!).

Any reasons that you know of why that is disallowed? It's not that expensive, and our old uni bodies weren't stitched together all that tightly to begin with.

Its disallowed because it provides a significant competitive advantage. Stitch welding seams is similarly disallowed because of the advantage it provides. FWIW, welding up all the seams in a unibody can improve rigidity up to 75% or better.

Here is a really good read about chassis stiffening. While performed on a 1st gen Mustang, the results would be typical for most unitized construction car bodies.
http://www.pro-touring.com/showthread.ph...;highlight=sn65

Posted By: Skeptic

Re: Torque Boxes and other stiffeners - 11/14/12 09:34 PM

Thanks for the replies, I can understand the restriction in a pure stock class, but even my mildly modified a-body twists something fierce going around corners. This is a CA car that has NO rot and only minimal rust around the rear window-it used to have a vinyl top. Since it's a street car, with only occasional runs around the track, a cage isn't in the cards. I'll be welding the seams and frame connectors, torque boxes and adding gussets....and let the chips fall where they may.

Posted By: younggun2.0

Re: Torque Boxes and other stiffeners - 11/15/12 12:08 AM

I agree with them about the frame connectors. I did mine with 3x3" 1/8" wall square tubing. I can set the car on three jackstands and the doors still open and close like a new car.

Posted By: jcc

Re: Torque Boxes and other stiffeners - 11/15/12 12:44 AM

Quote:

The Mopar Chassis book actually recommends beefing up the sill plate in dedicated track cars.

Not clear to me, describe/define "sill plate" please.

Posted By: Mopar Mitch

Re: Torque Boxes and other stiffeners - 11/15/12 07:33 AM

Younggun... the pics look very good... that's how I'd like ot eventually make mine with good stiff metal... but the SCCa rules don't allow cutting through the floor pan (in class E/Street Prepared where I've kept the car setup to compete).

Posted By: TC@HP2

Re: Torque Boxes and other stiffeners - 11/15/12 05:39 PM

Quote:

Quote:

The Mopar Chassis book actually recommends beefing up the sill plate in dedicated track cars.

Not clear to me, describe/define "sill plate" please.

Sorry, the rocker panels. I'll see if I can find it and scan.