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DIY anti-roll/anti-sway bar?

Shocks, Springs, Brakes, Frame, Body Work, etc

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BillyGman

DIY anti-roll/anti-sway bar?

Post by BillyGman »

Although this might be a hair brained scheme, here it goes.....

I have a 16 ton hydraulic pipe bender at home. It can bend 1/2" diameter to 3" diameter pipe into angles up to and including 90 degrees. So what if I bought a piece of DOM steel tubing with a 1.5" diameter O.D. and a .250" wall thickness and bent it into a rear anti-roll/anti-sway bar for my street/strip car? Would it work? And more specifically, would it work w/out being heat treated? Are the aftermarket sway bars heat treated? If I didn't heat treat it, then would it still act like a spring and have "memory" like it would need to? Or would it just twist and stay twisted?
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Post by JuicedBu »

Why bend one? Just use a straight piece of bar and make an anti-roll bar.
Ed-vancedEngines

Post by Ed-vancedEngines »

I suggest to not do this.

I do not think that the main long torsion bar is regular mild steel or 4130 steel. I would almost bet you money it is either spring steel or 4130 or 9310 that has a special heat treat to allow it to flex/twist and return to original shape. If it were stiff it would not do it's job becuase it would either brek or would not allow any difference of suspension movement. If it were mild steel or 4130 once it flexed/twisted it would be permanently twisted.

I kow of guys that have broken the cheaper factory built ant-roll bars llike Competition Engineering etc.

My suggestion is to take the money to buy a good quality professional Anti-Roll Bar from Rick Jones (Quartermax Race Cars) Jerry Bickel, Alston Engineering, Tim Msamis or David Wolfe. The type of material used for bearings is important. The method of attaching the arms to the Torsion Bar is or can be important. Most of the Anti-Roll Bars do not have splined ends and the arms are held in place by just tightening the bolt clamping them to the smooth bar ends. Splined ends with the similar bolt to tighten them to t he bar is in my opinion the best way to go.

If you have cheap built Ant-Roll Bars they can be dangerous if they break at the wrong time. A guy in Houston almost climbed the wal when his cheap Ant-Roll Bar from Competition Engineering Broke while he was already on a 4 ft. wheelie. The car suddenly jerked to the right toward the wal and came close to hitting a guy taking the pic of all of this, Scott Singleton. That pic showed the car in a really bad twisted shape too.

Even if you are poor. I suggest to save and to buy high quality suspension parts.

Ed
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Post by Cammer »

Another good post, Ed!

Check out Rick Jone's bars and consider his chassis tuning book:

http://www.rjracecars.com/

Your best money is always spent on safety!

Go back and read the first sentence of your post!

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BillyShope
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Post by BillyShope »

Yes, I agree with Ed. But, there is a relatively cheap and easily implemented trick you can use while you're saving your quarters. It's pretty common among oval racers, but relatively rare among dragracers. The trick is to limit the rebound of the right front wheel. The oval racers usually use a chain, encased in rubber tubing to prevent "kinking." The idea is that the chain will be slack during normal driving and cornering, but will, during launch, go taut before the left front reaches its rebound limit. The result is that...from that instant on...the weight transfer will be sucked entirely from the right front and, since the sum of right front and right rear wheel loads must be a constant (otherwise, the car would be rolling over), rear wheel loading will be more equal. And that, after all, is what you're trying to accomplish with the anti-roll bar. Some dragracers swear by this trick and others simply swear at it, saying they don't like the jolt as the chain goes taut. But, this is typical of most suspension changes.

For other suggestions on achieving equal rear tire loading:

http://home.earthlink.net/~whshope
BillyGman

Post by BillyGman »

This is the anti-roll bar I've decided to purchase (although I chose the option to get it in black instead of red). It's a solid bar with a whopping 1 3/8" diameter, that is fully intended for drag racing, but unlike those straight anti-roll bars with the splined ends, this bar will not cause suspension binding. Therefore, it's tame enough to be used for street driving w/out jarring the fillings out of your teeth. I have spoken to a number of guys who use them on their street/strip cars, and they all love them.They stop the car from rolling side-to-side during launches at the dragstrip, and so the car launches straight. And they're priced very reasonable at $350 from BMR fabrication.....

http://www.bmrfabrication.com/A-Body.htm

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rallye bob
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Post by rallye bob »

I went with the HR parts N stuff unit ( http://hrpartsandstuff.com )
For my GM "A" body car. Works great...... 8)
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BillyGman

Post by BillyGman »

Yes, I hear good things about thiose bars too. They're very similar, and they work the same way as the BMR bar that I bought. They mount the same too. The main difference between the two is that the HRP bar is a 1.250" diameter and is hollow, and the BMR bar is solid and is a 1. 3/8" diameter. But from what I hear, they both work very good.
Ed-vancedEngines

Post by Ed-vancedEngines »

Those ati-roll bars normally called sway bars should be fine on street driven cars. Of course they would also be helpful at the track too. I never advise to use a serious racing suspension component on daily driven cars, even if I have occasionally done it myself.

The original posted question said nothing at all about driving the car around on the street.
Although this might be a hair brained scheme, here it goes.....

I have a 16 ton hydraulic pipe bender at home. It can bend 1/2" diameter to 3" diameter pipe into angles up to and including 90 degrees. So what if I bought a piece of DOM steel tubing with a 1.5" diameter O.D. and a .250" wall thickness and bent it into a rear anti-roll/anti-sway bar for my street/strip car? Would it work? And more specifically, would it work w/out being heat treated? Are the aftermarket sway bars heat treated? If I didn't heat treat it, then would it still act like a spring and have "memory" like it would need to? Or would it just twist and stay twisted?
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under construction.
Although it does say street car in his signiture, now days that can mean a whole lot of different things. Serious Race Cars are now called street cars. We are into what is called street car racing and those have upwards of 2,000 plus hp and can not be driven very far on a street but are called steet cars.

My opinion of a street car is a daily driver. Most do not agree though.

Ed

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Post by rallye bob »

Ed;
I run the HRPS bar I pictured, on my "race only" GM "A" body car because I still run the "stock style" rear suspension. When/if I go to a more "race" suspension, I will certainly switch to a more "race" style anti-roll bar setup.
For now the "street/strip" bar works great for my application.
3500 lb, 10.97 et @ 122 mph 1.49 short times.
Thanks for all the great info on this site.... 8)
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Re: DIY anti-roll/anti-sway bar?

Post by pdq67 »

Boy, am I digging!!

Is ADDCO still around?

I have their front and rear S/B's on my '67 Camaro and the price was right.

Got them AT THAT TIME through W/JCW's, but it's been years..

pdq67
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Re: DIY anti-roll/anti-sway bar?

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Re: DIY anti-roll/anti-sway bar?

Post by lewy-d »

what is it about the straight bars with splined ends that causes binding?
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Re: DIY anti-roll/anti-sway bar?

Post by emsvitil »

I haven't had any problem with ADDCO BARS.............

But their add-on mounts can be cheesy and often need some re-engineering / re-inforcement..........
Ed
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