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which type of sway bar would you get?

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Discussion Starter · #1 ·
alright guys.. my last poll turned out pretty good if i do say so myself.. lots of usefull info.. so i thought i would try it again.. i will eventually get some sways, nothing extreme probably some 24+mm front and rear.. but ive noticied that in the market you can either get hollow or solid bars.. other than the obvious (hollows are lighter) what are the advantages and dis-advantages of both?
 

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The 25mm hollow sways are no where near as stiff as the solid 24mm. If you need the roll stiffness of the 24mm you will be disatisfied with the hollow 25mm.
 

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Solids: Tend to be cheaper and are stiffer compared to the same diameter hollow bar. More choices out there.

Hollow: Tend to be more expensive but are lighter, not as stiff as the equivalent solid bar.

Functionally, they are equivalent if comparing the "equivalent" bars. So really it just comes down to finding a bar with the right stiffness you want with a price you are willing to pay. The weight difference between solid/light isn't a huge amount (and the weight is down low in the car) so I wouldn't really make weight a deciding factor.
 

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Discussion Starter · #4 ·
ok, well heres what is confusing.. according to hotchkis, their hollow bars are stiffer/stronger than solid bars.. also (and im not a physics major) by design i would think the hollow bar would be stiffer/stronger..
im not looking for somthing that is "auto x" stiff cause i wont be doing that (thats why i say i will be going with around 24-25mm) but i just wanna see the diffirences between the 2 designs..
 

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whitson01 said:
ok, well heres what is confusing.. according to hotchkis, their hollow bars are stiffer/stronger than solid bars.. also (and im not a physics major)
Where did you read that? They're stiffer for a given weight, but certainly not for a given diameter.
 

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whitson01 said:
ok, well heres what is confusing.. according to hotchkis, their hollow bars are stiffer/stronger than solid bars.. also (and im not a physics major) by design i would think the hollow bar would be stiffer/stronger..
im not looking for somthing that is "auto x" stiff cause i wont be doing that (thats why i say i will be going with around 24-25mm) but i just wanna see the diffirences between the 2 designs..
get the whiteline 24/26 front and 20/24 rear.

that is perfect for DD, not too big not too little.

whiteline has a good little write up on why solid is better on their website.
 

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Discussion Starter · #7 ·
stretch said:
Where did you read that? They're stiffer for a given weight, but certainly not for a given diameter.
from hotchkis' website:

Front 1" (25.4 mm) Hollow +50%
Rear 1" (25.4 mm) Hollow
3 Position Rear +50%, +90%, +160%

Hollow VS Solid (To be used as referece only)
Front Bar Rates:
Hotchkis Hollow Bar = 880 lbs/in.
Solid (7/8") = 725 lbs/in.

Rear Bar Rates:
Hotchkis Hollow Bar = 300 lbs/in.
Solid (15/16") = 300 lbs/in

am i misunderstanding this?
 

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whitson01 said:
from hotchkis' website:

Front 1" (25.4 mm) Hollow +50%
Rear 1" (25.4 mm) Hollow
3 Position Rear +50%, +90%, +160%

Hollow VS Solid (To be used as referece only)
Front Bar Rates:
Hotchkis Hollow Bar = 880 lbs/in.
Solid (7/8") = 725 lbs/in.

Rear Bar Rates:
Hotchkis Hollow Bar = 300 lbs/in.
Solid (15/16") = 300 lbs/in

am i misunderstanding this?
You are comparing different diameters. 7/8" solid vs 1" hollow and 15/16" solid vs 1" hollow.

Note: hard to compare holes position as it changes the lever arm.
 

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i ahve cusco sways as well. and they are solid and very very stiff. however they weigh so much more than other hollow sway bars. it must weight about 20lb. where as hollow ones are about 5-10lb. And when i had my celica, i had full hotchikis suspension. and i remember their sway abrs were very flexible. where as my cuscos can't be flexed at all with human strength
 

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The center of a torsion bar does nothing as far as stiffness is concerned. It's just dead weight. It's the O.D. that does all the work. The spring rate is a function of the diameter cubed.

For a given stiffness a hollow bar will be slightly larger in O.D. and a lot lighter. If the hollow bar is a lot bigger in O.D. then wall thickness becomes a problem. Think beer can...

With proper end links my first choice would be hollow.

I have a Perrin solid front bar as 2 years ago I could not get a Cobb hollow one. Huge back order problems then.
 

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yeah just make sure you get some endlinks, at least for the rear. its a must
 

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Web_Foot_STi said:
The center of a torsion bar does nothing as far as stiffness is concerned. It's just dead weight. It's the O.D. that does all the work. The spring rate is a function of the diameter cubed...
less the airspace in the middle so you are only accounting for wall thickness on a hollow bar...
 

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For a daily driver, I would get the Cobbs or Hotchkis (which I have and love). I am also running KB rear endlinks.
In northern CA, where the roads are ****, I would think having a beefy bar like the Whitline 27mm ones would make my car skip around on choppy turns.
If you are going to auto x or track, that would call for something big.
 

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Turninconcepts.com said:
less the airspace in the middle so you are only accounting for wall thickness on a hollow bar...
Correct.

Spring rate

Solid bar:
R=(G*D^4)/(584*L)

Hollow Bar:
R=(G*(D^4-d^4))/(584*L)

D = OD"
d = ID"
G = Modulus of rigidity = ~30,000,000 psi for steel
L = effective bar length"
R = spring rate lbin/deg

I was trying to keep it simple

The highest stress is in the O.D. of the bar but, that is another set of equations.
 

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get hotchkis, the word is cobb's are hotchkis bars painted blue and marked up. Although I've also heard that that was true in the past but recently Cobb started making their own bars.

But hell, Hotchkis has been around for a long time doing suspensions stuff and the price is right.
 

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whitson01 said:
thats funny. out of 37 votes the results are still kinda close..
I think the results would be hugely in favor of hollow if larger diameters were available. They're inherently better designs, but Whiteline is currently making the bigger (arguably better) sizes.
 

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I don't know if I would say that hollow is inherently better. As far as the front bar goes, you could go with the Strano 32mm, which is only slightly stiffer than the Whiteline 27-29mm. But despite the lighter weight of the hollow bars, I don't think it makes much of a difference. A few pounds at the lowest point on the car is going to be negligible. But you are correct that Whiteline is very smart for making the sizes they do. It's also nice that they offer a variety of sizes to suit different needs. My 27-29mm front and 24mm rear are great.
 
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