I'm looking into how sway bars are made and need information on the material that is used.

Are the bars hollow or solid?
What material is typically used?
If bars are hollow, what wall thickness is commonly used?

Stock sway bars are solid. Some of the $$$ ones are hollow, but I don't know the wall thickness. (Silly idea anyway; it saves almost no weight and the little it saves is way down at the bottom of the car anyway!)

I don't remember the alloy, but I believe it is one of the mild steels. A google search should turn up spring rate calculations for torsion bars, which should be pretty similar to those for sway bars (once you factor in the different lengths). I assume that's why you need the configuration and composition of the bars, yes?

--DD

QUOTE (Dave_Darling @ Feb 17 2006, 08:18 PM)

I don't remember the alloy, but I believe it is one of the mild steels. A google search should turn up spring rate calculations for torsion bars, which should be pretty similar to those for sway bars (once you factor in the different lengths). I assume that's why you need the configuration and composition of the bars, yes?

Yup, thanks. I'll search around google for the calculator.

I was hoping to make a custom sway bar for my car using chromoly tubing (.120) or some other hollow tube that I can bend with my JD2. I realize I could buy a sway bar and make it work...whats the fun that

If you're mounting a front bar in the stock location, you can't bend it or it won't install.

speedway engineering

......this is one of those items you are better off biting the bullet and fabricating an assembly from items you can buy off the shelf (see link above)

You might find some info over at Hotchkiss Suspension (do a google or yahoo), they may have some basic data at their site. Hollow bars sometimes referred to as "Gun Drilled" or "Charley Bars" . My old bud Charley Spira started making hollow bars awhile ago, and I presume that the name just stuck
Marty

QUOTE (Mueller @ Feb 17 2006, 11:27 PM)

speedway engineering ......this is one of those items you are better off biting the bullet and fabricating an assembly from items you can buy off the shelf (see link above)

Mike this is exactly what I was looking for and your point is well taken:
http://www.1speedway.com/swaybar385.htm

They mention "special high-grade spring steel" as the material. I think I'm going to try it out with some chromoly tubing and a couple of these:
http://cgi.ebay.com/ebaymotors/Energy-9-51...612713559QQrdZ1

And, I can weld on some mounting points on the ends and have them bolt into the shocks bottoms....not for the 914 by the way. Lets see how it works....

swaybars are heat treated...not something you can do at home too easily....this is not an item you want to fail while in a corner, the weight of the car will get transferred too quickly if something breaks resulting in a crash or ???

Carroll Smith in his book Tune to Win states that mild steel sway bars are just barely adequate. The failure mode is that the bar will yield and take a set. When that happens your suspension will be preloaded one way or another and your corner weights will be all off. Smith recommends using 4130 seamless tubing and heat treating to Rc34-38. I made my own front bar from a length of solid 4xxx series solid bar. I'll let you know how it works when the hell hole gets repaired and the jack stands are removed. Have fun

Bill

QUOTE (Borderline @ Feb 18 2006, 08:58 AM)

Carroll Smith in his book Tune to Win states that mild steel sway bars are just barely adequate. The failure mode is that the bar will yield and take a set. When that happens your suspension will be preloaded one way or another and your corner weights will be all off. Smith recommends using 4130 seamless tubing and heat treating to Rc34-38. I made my own front bar from a length of solid 4xxx series solid bar. I'll let you know how it works when the hell hole gets repaired and the jack stands are removed. Have fun Bill

Please do update ....

Mike: Yeah, it's not something I want to fail under hard driving....Not saying i'm going ot run my own for sure...just looking into it.