Hollow Sway Bars
07-25-2006, 02:50 PM
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Hollow Sway Bars They make sway bars hollow and solid. Whats the difference when it comes to performance.
Guy is selling his slp ones that came with his firehawk. 35 mm in front 21 mm in back but atleast the front one is hollow.
Thanx for any help I have no idea what solid or hollow is going to mean other than of course hollow is lighter.
Thanx Chad
Guy is selling his slp ones that came with his firehawk. 35 mm in front 21 mm in back but atleast the front one is hollow.
Thanx for any help I have no idea what solid or hollow is going to mean other than of course hollow is lighter.
Thanx Chad
07-25-2006, 03:23 PM
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The hollow swaybars are lighter than the solid ones, but don't offer as much torsional rigidity. However, the additional rigidity that a solid bar offers over a hollow one is not a whole lot, because as you get closer to the center of the bar, that metal provides less deflection force. So its really what you value: extra roll stiffness or lighter weight?
BTW, I have a solid 35mm S/T swaybar for sale, $85+shipping. It was probably the best mod I did to my car, but I'm selling my car, so I'm selling the swaybar too.
BTW, I have a solid 35mm S/T swaybar for sale, $85+shipping. It was probably the best mod I did to my car, but I'm selling my car, so I'm selling the swaybar too.
07-25-2006, 04:01 PM
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As Ackattack1 has mentioned at a given size a solid bar offers more rigidity. Although a well designed hollow bar with good wall thickness will keep the differences to a minimum. However the weight difference is huge... ST's front 35mm solid bar weighs almost double of a 35mm hollow bar. A hollow 35mm front and a 21mm solid rear is a nice balanced set IMO. I use a Sam Strano's 22mm hollow rear (upgraded from the stock 19mm solid) and as a matter of function offers the same performance of a 21mm solid, but saved 5/6lbs of unsprung weight.
Scott.
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07-25-2006, 04:40 PM
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Solid bars are very little stiffer than hollow bars are. Some yes, but how much is a function of many things, a big one being the diameter of each, and the wall thickness of the hollow bar.
Solid bars are heavy. Solid bars are cheaper. The bars you mention... the optional suspension SLP bars are hollow in front, but the rear is solid. A hollow 35mm front like the ones we make, or SLP has are about 14 pounds lighter than a solid one like the ST bar, but mine has a little more wall thickness, and slightly different bends that add up to a stiffer bar. A hollow 22mm rear such as mine is about 5 pounds less than a stock 19mm rear, and about 6.5 less than a solid 21mm rear. All of which, as mentioned is unsprung weight.
Solid bars are cheaper. I sell solid bars for that reason still. Hollow bars are lighter and don't give up performance (if sized correctly, which is not a small consideration). Solid doesn't make them "bad", and hollow doesn't make them "good". The amount of roll stiffness does that, and if you can make them lighter while keeping the roll stiffness where we want, then hollow is better just because of weight.
All front bars on these cars are hollow from GM originally.
My hollow bars are $379 for the set, including all the endlinks and urethane bushings. Sized for handling. Developed on my car, I run them on my car.....
Solid bars are heavy. Solid bars are cheaper. The bars you mention... the optional suspension SLP bars are hollow in front, but the rear is solid. A hollow 35mm front like the ones we make, or SLP has are about 14 pounds lighter than a solid one like the ST bar, but mine has a little more wall thickness, and slightly different bends that add up to a stiffer bar. A hollow 22mm rear such as mine is about 5 pounds less than a stock 19mm rear, and about 6.5 less than a solid 21mm rear. All of which, as mentioned is unsprung weight.
Solid bars are cheaper. I sell solid bars for that reason still. Hollow bars are lighter and don't give up performance (if sized correctly, which is not a small consideration). Solid doesn't make them "bad", and hollow doesn't make them "good". The amount of roll stiffness does that, and if you can make them lighter while keeping the roll stiffness where we want, then hollow is better just because of weight.
All front bars on these cars are hollow from GM originally.
My hollow bars are $379 for the set, including all the endlinks and urethane bushings. Sized for handling. Developed on my car, I run them on my car.....
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07-27-2006, 08:26 AM
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For ***** and grins, let's make a simplistic comparison between a hollow and solid swaybar (and I emphasize "simplistic") from a theoretical standpoint. In pure torsion, resistance to twisting is a function of the torsional constant (J) along with the length of the member, the applied moment, and the Modulus of rigidity. Torsional constant is really the only property based on material cross-section. Now, knowing this and holding all else constant except for the fact that one is hollow and one is not (I did say "simplistic", right? 
), we can say that a 32mm solid bar has slightly LESS resistance to twisting than would a 36mm hollow bar with only 4mm wall thickness and yet the solid bar would weigh almost exactly TWICE as much.
Bottom line is that in almost all cases, if there is room and if additional cost is not an issue, a properly designed hollow bar beats a solid bar. That's why OEM's use them a lot.
), we can say that a 32mm solid bar has slightly LESS resistance to twisting than would a 36mm hollow bar with only 4mm wall thickness and yet the solid bar would weigh almost exactly TWICE as much.Bottom line is that in almost all cases, if there is room and if additional cost is not an issue, a properly designed hollow bar beats a solid bar. That's why OEM's use them a lot.
