Originally posted by Doohickie@Apr 3 2006, 11:06 PM That's a pretty good price for both front and rear and poly bushings. What are the specs on the sway bars (diameter as compared with stock diameter)?
I upgraded just the rear sway bar on my Elantra and it made it handle like a go cart- lots of fun to drive now!
The bars are about an 1/8" bigger in diameter, but the bigger issue is the stiffness. With the materials and bigger diameters these bars are about 200% stiffer in torsion. Now, that doesn't necessarily mean 200% less body roll, but I can assure you that the bars make a big difference in the body roll characteristics. Thanks for the question, we look forward to stiffening up your suspension soon...
Originally posted by Chip@Apr 7 2006, 12:11 PM The bars are about an 1/8" bigger in diameter, but the bigger issue is the stiffness.* With the materials and bigger diameters these bars are about 200% stiffer in torsion.* Now, that doesn't necessarily mean 200% less body roll, but I can assure you that the bars make a big difference in the body roll characteristics.* Thanks for the question, we look forward to stiffening up your suspension soon...*
Beware of claims. First of all, all steels are about the same stiffness (Elastic Modulus, or unit stiffness, of 210 GPa according to U.S. Steel), so material changes do not make the bar stiffer. Secondly, what size is the stock sway bar? To get a 200% increase in stiffness (or 3 times as stiff), with a 1/8" (3 mm) increase in diameter, you would have to be going from 10 mm to 13 mm diameter. I can't believe the stock sway bar could be any less than 13 or 15 mm. There's no way to get a 200% stiffness increase with 3 mm increase starting from a sway bar of larger than 10 mm diameter.
Sway bar stiffness is proportional to the fourth power (i.e., the square of the square) of the diameter. 10 mm to the fourth power, times 3 (for 200% stiffer) = 30,000. The fourth root of 30,000 is 13.16. Anything bigger than 10 mm, and you can't get a 200% improvement with a 3 mm increase in diameter.
Now, if by 200%, you mean twice as stiff, that is more reasonable. But twice as stiff is only 100% stiffer. This could be done by going from 15 to 18 mm diameter, a difference of 3 mm (or about 1/8").
By the way, You never answered my question: What is the OEM sway bar diameter, and what is the new aftermarket diameter. It is a simple task to compare the stiffnesses using the chart in this pdf document.
Originally posted by Doohickie@Apr 10 2006, 11:42 PM Beware of claims. First of all, all steels are about the same stiffness (Elastic Modulus, or unit stiffness, of 210 GPa according to U.S. Steel), so material changes do not make the bar stiffer. Secondly, what size is the stock sway bar? To get a 200% increase in stiffness (or 3 times as stiff), with a 1/8" (3 mm) increase in diameter, you would have to be going from 10 mm to 13 mm diameter. I can't believe the stock sway bar could be any less than 13 or 15 mm. There's no way to get a 200% stiffness increase with 3 mm increase starting from a sway bar of larger than 10 mm diameter.
Sway bar stiffness is proportional to the fourth power (i.e., the square of the square) of the diameter. 10 mm to the fourth power, times 3 (for 200% stiffer) = 30,000. The fourth root of 30,000 is 13.16. Anything bigger than 10 mm, and you can't get a 200% improvement with a 3 mm increase in diameter.
Now, if by 200%, you mean twice as stiff, that is more reasonable. But twice as stiff is only 100% stiffer. This could be done by going from 15 to 18 mm diameter, a difference of 3 mm (or about 1/8").
By the way, You never answered my question: What is the OEM sway bar diameter, and what is the new aftermarket diameter. It is a simple task to compare the stiffnesses using the chart in this pdf document.
For the price being charged, I doubt an advanced alloy is being used. Rather than guessing, maybe we should wait for Chip to post the technical information.
What are the diameters of the stock bar versus the aftermarket one? Can we see how you calculate the 200% (3 times) stiffness value?
On my Elantra, I went from a 15 mm stock sway bar to the 19 mm bar made for the Hyundai Tiburon. According to the stiffness chart in my other post, that's a 157% increase (about 2.5 times stiffer), and it's a huge difference. There is another Tibby sway bar that is 18 mm diameter and several Elantra owners I know have that one and are also impresed.
I'm not saying that this bar is snake oil; I'm sure it stiffens things up significantly. I'm just curious how he figures 200% improvement.
Originally posted by Doohickie@Apr 12 2006, 02:05 PM For the price being charged, I doubt an advanced alloy is being used.* Rather than guessing, maybe we should wait for Chip to post the technical information.
What are the diameters of the stock bar versus the aftermarket one?* Can we see how you calculate the 200% (3 times) stiffness value?
On my Elantra, I went from a 15 mm stock sway bar to the 19 mm bar made for the Hyundai Tiburon.* According to the stiffness chart in my other post, that's a 157% increase (about 2.5 times stiffer), and it's a huge difference.* There is another Tibby sway bar that is 18 mm diameter and several Elantra owners I know have that one and are also impresed.*
I'm not saying that this bar is snake oil; I'm sure it stiffens things up significantly.* I'm just curious how he figures 200% improvement.
I think that you do have a valid point. However, we may be getting into semantics and interpretation. It also depends on how you interpret percentages. I know that I recall in my engineering classes back in the day that if a rigid body, say "A" is compared to another rigid body "B", then if the stiffness comes out to A=B then we could say that A is 100% as stiff as B and vice versa. By your logic, if A=B then you would say that A is 0% as stiff as B which doesn't make sense. I totally get your point about the bars being 2x vs. 3x as stiff. It's just the use of percentages that can be misleading.
IMHO, I'm guessing that Chip means that the bars are *twice* as stiff as the original bar, which is quite plausible, even if I have to use that chart you provided(which, btw, has very little bearing because if the chart were to truly measure stiffness, then it doesn't take into account how long the end links are and polar moments etc, they would all be different depending on bar design).
The point here, is will the bars make a noticeable difference once installed, and it seems that they will. I'm always optimistic when it comes to new products, especially in the current state of the Suzuki aftermarket. In the end, we will all have to wait on a report from someone who has just had them installed.
4130 isn't a rare alloy at all. the suspension and rollcage on both my GRM car and my daewoo in progress are both made from 4130. it's only about twice the price of mild steel and i could produce mild steel for WAY less than he is charging, so i figure it's 4130 chromoly.
again though, moment arms can change and apply stiffness to the system. he may have more bends, or fewer bends, to create a stiffer design.
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