How are sway bars made?
 

Was just thinking that I really dont know how they are constructed. I've been building a couple of front subframe braces for my Saab 900 Turbo, and was looking at the sway bar at the rear and thought, it wouldnt be too hard for me to fabricate one based on the design of the stock one.

Is this something that conceivably could be done by a DIY'er, or does it involve heat treating, pre-tensioning, etc.. I have access to high quality metal, hence why I was asking.

I've been toying with the same idea. ;)

I would imagine they are mandrel bent and then heat treated. Don't know if heat would be required for the bend. Having done some (limited) bending of tubing and round stock in the past, I can tell you that it ain't as easy as it looks. It's tough to get the angles just right without building a jig, and you have to deal with some springback.

I'd bet it would be TONS easier and cheaper to just buy some used ones and be done with it. Unless you like this kind of stuff ;) (I do)

I've been toying with making some adjustable bars for my 911, or possibly just adjustable lever arms and drop links that will work with the stock bars.

Have fun,
Jim

We are talking two 45 degree bends on this. I have a tube bender, so a little heat, and walla... And yes, I enjoy seeing if i can do this sort of thing.

I'm thinking that I would want to vary the angles at which the bar attaches to the car to give it a bit of pre-tension?

If you have a bender and some bar stock, I'd give it a go! Plus, if you get the stock cheap, you could probably afford to screw a couple up.

Off topic: did you get rid of all your e30 stuff?

Jim

what are you loking for? I have a few odds and ends

How bout starting with some simple spring rate calculations? Otherwise your fooling yourself. It ain't rocket science but it is science.

Its not "a little heat" guys. To get steel to rebound to the orginal shape and to be uniform, its a long and involved process. Not rocket science but takes a while and I would bet a very large oven. We are not going to get our size sway bars in any home oven that I know of so buying used would be a lot easier...

Just as a side note, I would like to assure you guys that you are indeed nuts for considering this.

Hell, I think I'll forged a crank shaft this weekend......

Ten years ago, I probably could have done that. I made knives and sword for a living back then.

Great minds think alike...;)

http://forums.pelicanparts.com/porsche-911-technical-forum/171263-what-sway-bar.html

Thank You, now bite me repeatedly until you draw blood

I'm a lot more resourceful than you think.

You could cut square ends on the bar and fab ends with the square hole to clamp on. You could also weld the ends on.

i thought a sway bar was one that moved just a little after happy hour.......what do i know??

You should see the Fuchs I forged with a waffle maker.

They're born that way . . .

Lots of interesting comments here. I think I stated in my first post that this probably doesn't make any real sense financially, since good used anti-roll bars can probably be had for next to nothing, and there would be no way to recoup the initial investment of fabricating your own set unless you planned to sell a few (a bunch :eek: ) of them.

I also agree with the comments made about heat treating, spring rate calculations, etc. That would be one of the first things one would do when researching this idea, after posting on Pelican, of course ;)

Most of us don't have an oven suitable for heat treating a bar once it was bent, but there are places that will do this for you. ($$$) Most of us don't have a means of bending 3/4" 4140, and, quite frankly, I'm not sure if I would trust a tubing bender for the job. But it can be done. (more $$$)

Does it make sense? Probably not. Look at what aftermarket bars go for from companies such as Tarrett, Smart, Welt, and Elephant. That should give one an idea of the $ investment, research, and testing that goes into making a quality product.

I happen to have access to some pretty nice manufacturing equipment, and I know how to use it, or know how to find someone who knows more than me to do it for me. That's why I encouraged Jason to give it a go, since I assumed he was going to do enough research to, at the very least, not hurt himself. Will he end up with a quality product that works and last more than one drive? Who knows, probably not. But he might learn something, and have fun doing it.

And, I think that's one of the primary reasons most of us here on Pelican are DIYers. :)

Jim

Re: How are sway bars made?
 

Make sure it is the right alloy. You need spring steel which is not as easy to work with as mild steel. Here's a couple links.

http://www.engineering.com/content/ContentDisplay?contentId=41005011

http://www.mech.uwa.edu.au/DANotes/springs/fatigue/fatigue.html

Like I am making my own camshaft blank, I would even consider making say a 12 cylinder engine out of a couple of 911 engines, but I would never consider making a sway bar, unless I was IN that business to begin with.

Geez Mr. Grumpy.......

Re: Re: How are sway bars made?
 

He's right. Spring steel is pretty difficult to work with. When I made knives and swords, we used 5160 spring steel a lot. Tough stuff!