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Sway bars


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Just want to let you guys know that Addco still produces (front & rear) sway bars for Datsun pickup trucks. I was told by a few different people that this wasnt true so I contacted Addco directly and spoke with a guy named John. John said that they were still avaliable and a contact to a different to company who could give me a better price then even Addco could give me. So I contacted the company and I ordered 4 complete sets from them for a great price. Upon talking with the owner Brad of Never Enough Auto (http://www.neverenoughauto.com) he said that he would give a great deal to anybody that used them. Origionally I was quoted $292 shipped (cheaper than directly from addco), but of course I got a bit of a better deal be it that I purchased more then once set. I HIGHLY recomend Brad and his company; Never Enough Auto. He was great to do business with, very responsive and an all around good guy. It's very far and few between when you find a good company to deal with for old school import parts, so please if you have any interest in putting front and rear sway bars on your 620 or 521 please buy from them! I should be receiving my sway bars in within the next week or so and will post picture when I get them

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I had a general idea of what sway bars do, but thought this thread would be a great place to post this wiki info to educate anyone, like myself, who is trying to learn. Hope I am not hijacking!


"A sway bar (also stabilizer bar, anti-sway bar, roll bar, or anti-roll bar, ARB) is an automobile suspension device. It connects opposite (left/right) wheels together through short lever arms linked by a torsion spring. A sway bar increases the suspension's roll stiffness -- its resistance to roll in turns, independent of its spring rate in the vertical direction.




* 1 Principles

* 2 Drawbacks

* 3 See also

* 4 External links




In a turn, the sprung mass of the vehicle's body rotates around its roll axis. The roll axis is a line that joins the front and rear roll centers (SAEJ670e). If the vertical distance between the roll axis and the center of gravity is not zero, a torque (roll moment) equal to the centrifugal force times the distance between the center of gravity and the roll axis will be exerted on the sprung mass, causing the body to lean towards the outside of the turn. This force is called the roll couple. One effect of body (frame) lean, for typical suspension geometry, is positive camber of the wheels on the outside of the turn and negative on the inside, which reduces their cornering grip (especially with cross ply tires).


Roll couple is resisted by the suspension roll stiffness, which is a function of the spring rate of the vehicle's springs and of the anti-roll bars, if any. The use of anti-roll bars allows designers to reduce body lean without making the suspension's springs stiffer in the vertical plane, which allows improved body control with less compromise of ride quality.


The spring rate of an anti-roll bar is based on the fourth power of the torsion bar's diameter, the stiffness of the material, the inverse of the length of the lever arms (i.e., the shorter the lever arm, the stiffer the bar), the geometry of the mounting points, and the rigidity of the bar's mounting points. Some anti-roll bars, particularly those intended for use in auto racing, are adjustable, allowing their stiffness to be altered by increasing or reducing the length of the lever arms. This permits the roll stiffness to be tuned for different situations without replacing the entire bar.


Anti roll bars provide 2 main functions:


The first is the reduction of body lean. The reduction of body lean is dependent on the total roll stiffness of the vehicle. Increasing the total roll stiffness of a vehicle does not change the steady state total load (weight) transfer from the inside wheels to the outside wheels, it only reduces body lean. The total lateral load transfer is determined by the CG height and track width.


The other function of anti roll bars is to tune the high g / limit understeer behavior of the vehicle. The limit understeer behavior is tuned by changing the proportion of the total roll stiffness that comes from the front and rear axles. Increasing the proportion of roll stiffness at the front will increase the proportion of the total weight transfer that the front axle reacts and decrease the proportion that the rear axle reacts. This will cause the outer front wheel to run at a higher slip angle, and the outer rear wheel to run at a lower slip angle, which is an understeer effect. Increasing the proportion of roll stiffness at the rear axle will have the opposite effect and decrease understeer.




Because an anti-roll bar connects wheels on the opposite sides of the vehicle together, the bar will transmit the force of one-wheel bumps to the opposite wheel. On rough or broken pavement, anti-roll bars can produce jarring, side-to-side body motions (a "waddling" sensation), which increase in severity with the diameter and stiffness of the sway bars. Excessive roll stiffness, typically achieved by configuring an anti-roll bar too aggressively, will cause the inside wheels to lift off the ground during very hard cornering. This, of course, is only possible if the regular spring rate actually allows the outside wheels to handle the much increased load. This can be used to advantage, in fact many front wheel drive production cars will lift a wheel when cornering hard, in order to overload the other wheel on the axle, so limiting understeer."

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sway bars for the trucks showed up yesterday and I dropped off Pl521sss set last night he posted some pictures in his project thread, nice product powder coated black with all the hardware and bushing cant wait to get them on my truck as well as my girlfriends

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sway bars for the trucks showed up yesterday and I dropped off Pl521sss set last night he posted some pictures in his project thread, nice product powder coated black with all the hardware and bushing cant wait to get them on my truck as well as my girlfriends



It looks very nice indeed.

Powder coated with zinc plated hardwares.


Let's see who will get them on their truck first this weekend. :D

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2eDeYe;31133']Awesome...just added http://www.neverenoughauto.com to my list of people that I still need to by parts from...:P


Thanks for doing the legwork for me :D


NO problem anything to help out the Ratsun guys. just wish the rear was adjustable, Hmm might have to modify that

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