Difference Between the Hollow and Solid Sway Bars?
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From: Bay Area, No. Cali
Difference Between the Hollow and Solid Sway Bars?
I've read up on the the different sway bar systems out for our cars and it seems some of them are full solid while some of them have a hollow core. Is there any difference performance wise between the two designs? Logically I would think the hollow ones are not as stiff and not as strong as the solid ones. But perhaps the hollow ones are made up of a stronger metal which allows the hollow core without any degradation in strength? Basically, I'm interested in getting the Eibach sway bar kit which is of the hollow core design. Just wondering if there's any disadvantages to the hollow core design vs the solid design. Thanks.
Re: Difference Between the Hollow and Solid Sway Bars?
I had the same question..but didndt have time to post and ask..
I was thinking solid would be better.. but I know nothing of the subject.. I was thinking about the Cusco sway bars
I was thinking solid would be better.. but I know nothing of the subject.. I was thinking about the Cusco sway bars
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Re: Difference Between the Hollow and Solid Sway Bars?
The hollow ones are better because they are lower in weight. Check out Hotchkis.net. They are a well known company that specializes in hollow sway bars for American cars. They have a FAQ that I don't know how to attach.
'03.5 BS Sedan, tint, XM, GroundingGear, Premium, Willow, Zaino, etc.......<P ID="edit"><FONT class="small"><EM>Edited by socalg35 on 11/24/03 01:44 PM.</EM></FONT></P>
'03.5 BS Sedan, tint, XM, GroundingGear, Premium, Willow, Zaino, etc.......<P ID="edit"><FONT class="small"><EM>Edited by socalg35 on 11/24/03 01:44 PM.</EM></FONT></P>
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Re: Difference Between the Hollow and Solid Sway Bars?
the strength between the two are almost the same. so the hollow one would be a better choice.
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Re: Difference Between the Hollow and Solid Sway Bars?
I actually just checked their site (WWW.hotchkis.net) and they show show the sway bars for $254 for our cars (coupe and sedan are the same price). That is for the front and rear. I used them on an Impala SS and they are nice!
'03.5 BS Sedan, tint, XM, GroundingGear, Premium, Willow, Zaino, etc.......
'03.5 BS Sedan, tint, XM, GroundingGear, Premium, Willow, Zaino, etc.......
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Re: Difference Between the Hollow and Solid Sway Bars?
Hollow sway bars are looking to achieve stiffness with lower weight. The center material of the bar has a smaller effect on the overall stiffness than the outer portion. I can elaborate on some of the engineering principles behind it if you desire.
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Re: Difference Between the Hollow and Solid Sway Bars?
My cusco (solid) sway bars will arrive on 11/28. I'll weigh them and then weigh the stock (hollow) bars and post here...
It might prove to be a good weight to stiffness comparison. Others can post weights of their bars when they get them. It would be good data to add to gsedan35's swaybar info (see the "Sway Bars only?" thread).
It might prove to be a good weight to stiffness comparison. Others can post weights of their bars when they get them. It would be good data to add to gsedan35's swaybar info (see the "Sway Bars only?" thread).
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From: Bay Area, No. Cali
Re: Difference Between the Hollow and Solid Sway Bars?
smcallis: I'd be interested to hear why the center portion of the sway bar has a smaller effect on the overall stiffness than the outer portion. Just can't picture why from an engineering standpoint.
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Re: Difference Between the Hollow and Solid Sway Bars?
lets say there is a transverse load on solid bar. the bottom portion of the bar will be subjected tension while the upper portion of the bar will be subjected to compression. the mid point of the bar however are not subjected to any kind of load what so ever. so... solid.. or hollow it doesn't matter... the loads are carried at the outter portion of the bar.
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Re: Difference Between the Hollow and Solid Sway Bars?
For two equivalently loaded and supported beams the factors that affect stiffness are the modulus of elasticity and the moment of inertia. The modulus is more or less fixed for a given material. All steels generally range from 28-30 e^6 psi. The moment of inertia for a solid round bar is pi/64*OD^4. For a hollow bar the moment of inertia is pi/64*(OD^4-ID^4). Its easiest to illustrate with an example. For convenience I've factored out the pi/64 since it's common to both equations. If you have a 3/4" OD solid bar the MOI is 0.316 in^4. For a 3/4" OD 1/4" ID bar the MOI is (0.316 in^4 - 0.004 in^4) = 0.3125 in^4. From this example you can see how small the ID contribution is to the MOI. So in this case you get a 12.5% reduction in weight while only taking a 1.1% penalty in stiffness. So culmination is correct, the loads are really carried in the outer portion of the beam. By concentrating the mass where the loads are being carried allows the designer to reduce weight while maintaining the beam's stiffness. It's the same principle as with a thin wide rectangular bar. Its much stifffer in the wide direction than the thin.
G35s 6MT Garnet Fire, Premium, Aero, Aero Body Kit, Winter Sport<P ID="edit"><FONT class="small"><EM>Edited by smcallis on 11/25/03 03:57 AM.</EM></FONT></P>
G35s 6MT Garnet Fire, Premium, Aero, Aero Body Kit, Winter Sport<P ID="edit"><FONT class="small"><EM>Edited by smcallis on 11/25/03 03:57 AM.</EM></FONT></P>
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From: Bay Area, No. Cali
Re: Difference Between the Hollow and Solid Sway Bars?
So I'm guessing the consensus here is all things being equal (or close to equal, ie. stiffness) one would want to go with the hollow bar instead of the solid bar for weight savings reasons. But the question is does the weight savings for the hollow bars vs the solid bars have any noticable effects? Probably not since the amount of weight reduced isn't a whole lot. Correct me if I'm wrong.
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From: NE AZ
RE: Weight reduction
you are looking for a cumulative effect, not an all at once effect.
Say you can save 100 lbs (pretty close at least) by going with an aftermarket exhaust from heads to tailpipe, then throw in savings from lighter wheels (as much as 50 lbs for all four wheels), factor in another 10-20 lbs from the sway bars, etc..... you get the picture it all adds up.
One downside to dropping weight. Too much reduction down low can raise your center of gravity. The above 180 lbs (6%) or so will merely offset the weight of the driver so you should be allright but extensive reduction under the car can move the center of gravity up too much. Wider tires (or larger dia. wheels) can offset this as well and maintain more contact patch between tire and ground.
Just remember this car is VERY well engineered and everything you do is a tradeoff, so plan on counterbalancing every mod with another. Great wheels and tires can make up for a lot of engineering changes.
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Black on Black 03.5 Sedan 6MT - Custom Catback, Custom Intake Tube, HyperGround Kit
Say you can save 100 lbs (pretty close at least) by going with an aftermarket exhaust from heads to tailpipe, then throw in savings from lighter wheels (as much as 50 lbs for all four wheels), factor in another 10-20 lbs from the sway bars, etc..... you get the picture it all adds up.
One downside to dropping weight. Too much reduction down low can raise your center of gravity. The above 180 lbs (6%) or so will merely offset the weight of the driver so you should be allright but extensive reduction under the car can move the center of gravity up too much. Wider tires (or larger dia. wheels) can offset this as well and maintain more contact patch between tire and ground.
Just remember this car is VERY well engineered and everything you do is a tradeoff, so plan on counterbalancing every mod with another. Great wheels and tires can make up for a lot of engineering changes.
Better Life thru Chemistry
Black on Black 03.5 Sedan 6MT - Custom Catback, Custom Intake Tube, HyperGround Kit