Does anybody out there know what the rockwell hardness of a front sway bar should be? I have a 21mm aftermarket bar of some sort. I was going to duplicate mine with 3/4 (19mm) bar stock. I checked mine on a hardness tester, it was 8. A piece of 4140 was 16, and a piece of cold rolled was 12.

thanks, gonzo

even if you get the alloy and heat-treat right, there is a big difference in stiffness between 19mm and 21mm...

if you already have the arms and droplinks, a bare bar is not expensive; it wouldn't surprise me if it were available as a separate (if perhaps unadvertised) part from some of our favorite suppliers, such as Tarett, for less than you'd pay to machine and heat-treat one bar ...

QUOTE (rdgonzo @ Feb 8 2005, 11:00 AM)

Does anybody out there know what the rockwell hardness of a front sway bar should be? I have a 21mm aftermarket bar of some sort. I was going to duplicate mine with 3/4 (19mm) bar stock. I checked mine on a hardness tester, it was 8. A piece of 4140 was 16, and a piece of cold rolled was 12. thanks, gonzo

here is some interesting reading on swaybar design...

no direct relationship to me as far as I know

Swaybar design by Scott Mueller

I have been thinking of doing something similar. Smart Racing Products sells their sway bars for $138 and they have various sizes. The whole kit is like $675, but you could make your own arms and linkages for a lot less. The problem with Smart Racing is that their bars have splined ends.

Tarret might be a good source since they have square end bars.

I put in a call yesterday to Pelican to see if I can just get a Weltmeister 22mm bar on its own. I'll see what they say today hopefully...

-Tony

Build your own, just came up with that thought the other day when I was browsing around the Hoerr website, bars run $60-90 (solid or hollow, splined) bars come in different lenghts, tubular bars come in different wall thickness (anyone know what wall thickness comes on the hollow sway bars out there?

Arms straight, curved, loooong, steel, aluminum.

www.hrpworld.com

Gonzo,
We use 4130 steel, heat treated to 165 KPSI ultimate strength for our bars. They are designed to be used the heaviest 911’s with stock springs, worst possible case. I think that works out to about 32 R on the hardness. With a light 914 you could probably get away with 4130 and no heat treating. I never heat treated the prototype bars on my personal car. I think that Weltmeister uses an even weaker material with no problems.

Travis,
Our bars are 1” OD with a .094” wall. That works out to about a 22mm solid bar equivalent size. HRP World has some nice looking parts. If you know what solid equivalent size you want and what OD, I can calculate the wall thickness for you.

Ira

Thanks IRA!