Fabricating tubular sway bars? - TCCoA Forums
 
LinkBack Thread Tools
post #1 of 15 (permalink) Old 12-06-2006, 05:01 PM Thread Starter
 
Join Date: Aug 2002
Posts: 1,267
Fabricating tubular sway bars?

Perhaps this is a stupid idea, but...I was thinking about asking a local off road shop that does a lot of roll cages and mandrel-bend exhaust about trying to replicate my solid sway bar using tubular steel, since I'm not happy with the few OEM tubular sway bar sizes. He said he might be able to do it depending on the radii necessary for the bends and the size steel we need. So does anyone here know what grade steel is used for tubular sway bars, and what wall thickness might be necessary? The guy at the shop said he could do 1.25-inch diameter, .120-wall chromoly without a problem. Would such a material be good enough? Any input

And my only motivation for such a project would be weight savings for my LX, which is becoming increasingly dedicated to autocross.
mercutio is offline  
Sponsored Links
Advertisement
 
post #2 of 15 (permalink) Old 12-06-2006, 05:42 PM
2nd Gear Poster
 
Join Date: Nov 2006
Location: Chicago
Posts: 113
your right, hollow bars are much lighter [and exponentionally stiffer]... stiffer to the point your going to be ripping the attachment mounts [be easy on the noobie, I havent exactly spent alot of time under this car... yet]. I did this to my project car and ended up having to the reinforce the sway bar mounts to the rear crossmembers to handle it [plus you are going to need some bushings that will fit and endlinks].

chromoly is probably going to be crazy overkill [and really jump the price on you].

do you happen to have any underbody suspension photos [sorry its not the type of weather I want to be outside jacking my car up].
Bensenvill is offline  
post #3 of 15 (permalink) Old 12-06-2006, 06:13 PM
Heavily Medicated Crime Fighter
 
Mark M. TCCoA VP's Avatar
 
Join Date: Jan 1997
Location: Batcave, Wakefield, MA
Posts: 2,073
Send a message via AIM to Mark M. TCCoA VP Send a message via Yahoo to Mark M. TCCoA VP
You both need to read the tech articles. We have 1 1/8", 1 1/4" and 1 3/8" aftermarket bars out there now. These are solid bars BTW.

Mark

"Mark M. TCCoA VP. Emeritus"

To the Batmobile ! ! !

ADDCO MN12 big bar R&D guru
Mark M. TCCoA VP is offline  
Sponsored Links
Advertisement
 
post #4 of 15 (permalink) Old 12-06-2006, 06:44 PM Thread Starter
 
Join Date: Aug 2002
Posts: 1,267
Quote:
Originally Posted by Mark M. TCCoA VP
You both need to read the tech articles. We have 1 1/8", 1 1/4" and 1 3/8" aftermarket bars out there now. These are solid bars BTW.

Mark
I have read the tech articles, and I have an Addco rear bar on my car now--perhaps you misunderstand my intent. I'm looking for a way to have a bar that's stiffer than stock, but not nearly as heavy as the 1 3/8 rear bar on my car now. A tubular bar would meet both of those requirements.
mercutio is offline  
post #5 of 15 (permalink) Old 12-06-2006, 09:58 PM
Heavily Medicated Crime Fighter
 
Mark M. TCCoA VP's Avatar
 
Join Date: Jan 1997
Location: Batcave, Wakefield, MA
Posts: 2,073
Send a message via AIM to Mark M. TCCoA VP Send a message via Yahoo to Mark M. TCCoA VP
What day is this again???? LOL sorry about that

"Mark M. TCCoA VP. Emeritus"

To the Batmobile ! ! !

ADDCO MN12 big bar R&D guru
Mark M. TCCoA VP is offline  
post #6 of 15 (permalink) Old 12-06-2006, 10:33 PM
Seasoned PostWhore
 
Join Date: Dec 2002
Location: Houston
Posts: 2,233
Quote:
Originally Posted by Bensenvill
your right, hollow bars are much lighter [and exponentionally stiffer]...
Ummmm, no. They are lighter, but no stiffer if they are the same diameter. The tubular one might be just a touch softer, but not enough to matter.

Mercutio:
I don't see why this wouldn't work. Give it a shot and report back. If you're going to this much trouble, you might as well make them adjustable. I can't remember exactly how much clearance there is in the front, but if you can make even two mounting points on the bar for the endlink, you would have 3 stiffness settings to play with (both to the back, both to the front, and one front and one back; they don't have to be symmetrical side to side).

In the back, I'm pretty sure there's room for a couple of adjustment points. Or, you can do something like what is shown in the link below, where the end link slides on the sway bar, and is clamped in place. The sway bar in the picture is designed to be attached to the rear axle, and the end links attach to the rectangular frame rails, hence that funky shape. Our bars mount to the body, with the end links to the suspension, but there's no difference in the way they work.

http://www.colemanracing.com/catalog...?cPath=49_1409

It's only funny until someone gets hurt.
Then it's freaking hilarious.


Adventures in ChumpCar Racing
Tobey is offline  
post #7 of 15 (permalink) Old 12-06-2006, 10:57 PM Thread Starter
 
Join Date: Aug 2002
Posts: 1,267
According to the chart in the tccoa tech article, one of the oem tubular bars was a rear bar in 1.04 inches for the rear of the 91-96 NA V6 cars. In 90 the solid rear bar measured .98 inches, and in 97 it measured .94 inches, assuming again that the info from that chart is correct. The chart also says that the 92 V8 car was the sole year for a tubular .94 inch rear bar, which was preceded and succeeded by a solid bar of the same size. Is this information correct? If so, is there a measurable difference in handling between any of these rear sway bars that might be extrapolated to compare a tubular 1.25 bar to a solid 1.25 or 1 3/8?

I'll admit that I'm no engineer, so this project would be solely a venture based on experimentation and guesswork. I picked the 1.25 inch diameter because it's the largest pipe this particular builder can bend, it's relatively close to my current 1 3/8 bar, and there are 1.25-inch sway bar bushings easily available. Whichever size tubing might actually work best, there still needs to be a bushing of a corresponding size available.

And again, the wall size is critical. Does anyone know the wall thickness of the OEM tubular bars, or the type of steel they're made from?
mercutio is offline  
post #8 of 15 (permalink) Old 12-07-2006, 01:48 AM
drag-aholic
 
BAGGED89's Avatar
 
Join Date: Jul 2002
Location: Fresno, CA
Age: 45
Posts: 1,056
I think sway bars are spring steel. You could look into using a long torsion bar and have splined end links on each end. I have seen really lifted trucks use this method before.

1989 LX Full Air Suspension
Owner / Operator BAGGEDBIRDS.com
BAGGED89 is offline  
post #9 of 15 (permalink) Old 12-07-2006, 07:14 AM Thread Starter
 
Join Date: Aug 2002
Posts: 1,267
I've seen that method used on Mustangs, too. One consideration for our cars, though, is that each end of our rear sway bars are lower than the center section to provide clearance, so I'm not sure a straight splined bar would work.
mercutio is offline  
post #10 of 15 (permalink) Old 12-07-2006, 05:26 PM
Seasoned PostWhore
 
Join Date: Dec 2002
Location: Houston
Posts: 2,233
A sway bar is a torsion bar. Some are bent for clearance, some are straight, but they work the same way. The splined ends are just for convenience. They allow easier installation, and you can swap in arms of different lengths to adjust the sway bar rate.

Remember, a sway bar works just like a torsion bar. When the suspension acts on each end differently, the bar twists; it doesn't (or shouldn't) bend. The distance from the center of the bar to where the end link connects controls how much leverage/torque is applied to the bar. That's why to make a bar adjustable, you fab it so that the connection point of the end link is adjustable, closer to the bar (less leverage) equals stiffer, farther from the bar (more leverage) equals softer.

As for the wall thickness, thicker would be better. Not so much to make it stiffer, but for longevity. If 1.25 x 0.120 is what the guy has, give it a shot. If it breaks, do something different. (I know, easy for me to say... )

It's only funny until someone gets hurt.
Then it's freaking hilarious.


Adventures in ChumpCar Racing
Tobey is offline  
post #11 of 15 (permalink) Old 12-07-2006, 05:39 PM
2nd Gear Poster
 
Join Date: Nov 2006
Location: Chicago
Posts: 113
yes, when it breaks it becomes much "softer"
Bensenvill is offline  
post #12 of 15 (permalink) Old 03-20-2007, 06:13 PM
Seasoned PostWhore
 
96bird's Avatar
 
Join Date: Nov 2002
Location: cleveland, TN
Age: 37
Posts: 2,936
Send a message via AIM to 96bird
Any new word on this Mercutio? Have you contacted Addco to see if they might bend a tube bar up for you? I just figured since they already have all of the bends for the front bar then it shouldn't be a big deal for them bend up some tube. I would like to have 1 3/8's front and rear bars in tube...a little less rate, but I would imagine they would weight a lot less than those crazy heavy solid bars.

Russell

JL's chassis braces, ST springs w/ 1 coil cut in rear (27.2" F 28" R), Airlift airbags (5 psi), Bilstein shocks, Cobra brakes F & R, ROH RT 17x9s, 255/285s Khumo Ecsta MX tires, 2.5" dual exhaust w/borla mufflers, 1 3/8 f & r bars, remote filter,subframe buildup, Al differential bushings, J-modded '02 tranny, 9.5" DD stall, 30K Hayden cooler, PI intake, 02 GT MAF, XCal 2

Want to talk/hangout with MN12 owners from GA? Go here.
96bird is offline  
post #13 of 15 (permalink) Old 03-20-2007, 06:14 PM
Tim
4th Gear Poster
 
Tim's Avatar
 
Join Date: Nov 2006
Location: Mankato,MN
Age: 33
Posts: 272
hmm
Tim is offline  
post #14 of 15 (permalink) Old 03-20-2007, 06:22 PM Thread Starter
 
Join Date: Aug 2002
Posts: 1,267
This project never really went anywhere for me. I never contacted Addco because it never really occurred to me that they'd take the time to do this.
mercutio is offline  
post #15 of 15 (permalink) Old 03-20-2007, 06:42 PM
Seasoned PostWhore
 
96bird's Avatar
 
Join Date: Nov 2002
Location: cleveland, TN
Age: 37
Posts: 2,936
Send a message via AIM to 96bird
Quote:
Originally Posted by mercutio View Post
This project never really went anywhere for me. I never contacted Addco because it never really occurred to me that they'd take the time to do this.
True....I was just wondering. I have just recently been taking some weight out of the car and was just looking into options.

Russell

JL's chassis braces, ST springs w/ 1 coil cut in rear (27.2" F 28" R), Airlift airbags (5 psi), Bilstein shocks, Cobra brakes F & R, ROH RT 17x9s, 255/285s Khumo Ecsta MX tires, 2.5" dual exhaust w/borla mufflers, 1 3/8 f & r bars, remote filter,subframe buildup, Al differential bushings, J-modded '02 tranny, 9.5" DD stall, 30K Hayden cooler, PI intake, 02 GT MAF, XCal 2

Want to talk/hangout with MN12 owners from GA? Go here.
96bird is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TCCoA Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome