Rear Sway Arm - Buggy

DesertGuy1

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I have been looking into using a rear sway arm system on a buggy that I am currently building. From my understanding, a rear sway arm can be used as a "traction control" device and reduce roll leading to a feeling of stability in the vehicle... under ideal circumstances. It seems some sort of variable sway arm system or a system that can be engaged/disengaged would be ideal given varying terrain (rough whoops vs. relatively flat turns)... however, I am still looking into a single rate system for the time being.

From looking at different vendors it seems that by playing with the variables of the components a final rate is achieved, such as: increasing the wall diameter of the sway bar up to a solid bar and shortening the rear arm will all lead to increasing the rate of the "system". Decreasing wall thickness and increasing arm length (leverage) will decrease the rating. Which brings about my question...

If a person was looking into a "happy-medium" type set-up to begin their tune from there, what rating would a person look for or what percentage of the shock rating would be a good starting point. It seems having multiple bars and arm lengths would be nice but is there a way to figure out a middle-of-the-road setup that would be decent the majority of the time?

Thanks and please correct if any of the above is not accurate.
 

racer56

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The diameter of the effective length (area in between bearing surfaces) of the bar determines the spring rate, not the wall thickness or if its hollow or solid. A 1" diameter solid bar has almost the same spring rate as a 1" diameter hollow bar.
 

DesertGuy1

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Hmm, looking at the following site, it would appear sway bar length, arm length and thickness/diameter all play a part unless I am reading it wrong.

http://www.1speedway.com/index.htm

Nonetheless... what % of increase in wheel rate is a good "all around" starting point when determining a rear sway bar's rate for a desert application (25-50%)?
 

racer56

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A good starting point would be a 1" bar with arms 18"-20" long. At the end of the arm have four mounting holes to give you adjust ability. 10 - 15% of your static wheel rate would be a good starting point.
 

DesertGuy1

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Thanks for the reply.... which brings up a question about wheel rate (WR).

WR = (Motion Ratio x Motion Ratio) x Spring Rate

In a dual coilover set up, which spring rate is used: Primary Rate, Rate of the Main Spring or Rate of the Tender Spring?
 
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mebuildit

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I have a Morphic buggy and had Rick Geiser make me a sway bar set up for my car. I had to give him certain info on the car and a couple of weeks he called me and had my set up. Rick also told me that for my set up a front sway bar was not recommended. I take his advise since I think and most do think Rick and his crew are the best in the business.
Might give him a call. He's a really nice guy, since I had never met him before that he has guided me in a great direction.
 
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