I need to replace my rear sway bar because my stock LS rsb is all rusted out. I dont know wether to go ITR 22mm, 23mm, or the ASR 24mm. I do plan on gettin a sub-frame brace in the "near" future too. Any suggestions?
22mm or 24mm rear sway bar?
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InnocentAlibi
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sgtmillhouse648 on Jan/04/10 said:And the other thing to think about with swaybars is that it's not only the diameter which makes a difference, but also the lengths of the moment arms/where it attaches etc. Look at the ASR 24mm and the Progress 24mm bars for example:
ASR:
![Image]()
Progress 24mm:
![Image]()
Notice how the Progress mounts at the shock mount farther 'out' on the LCA whereas the ASR mounts to the OE sway bar mounting point. This changes what is known as the motion ratio of the swaybar which is the relation between how far the wheels travel up and down to the distance the swaybar tilts up and down. This value ranges anywhere from 0-1. The wheel rate of the sway bar (effective springrate at the wheel) is the spring rate of the bar times the motion ratio squared.
By mounting the bar out at the shock, the motion ratio increases from roughly .55 to .8 IE the progress adds another 36% to the wheel rate opposed to the ASR given design was equivalent (it's not...the progress has shorter 'lever arms' which also increase the effectiveness of the bar).
SGT,
I really don't understand your last statement on the Progress lca mount location. So it simple terms does this lengthening of the lever arm, which would increase the Torque of the lever actually increase the "stiffness" of the bar or lower the "stiffness" compared to the ASR bar with identical diameters? Thank You
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2LDC2K on Dec/31/09 said:
I honestly looked back at the whole thread twice and have no idea why i said that lol. Reading fail.
OH! i see what it was. i confused the OP's post when he said 24mm ASR sway, i thought he said 24mm AND ASR SFB.
so, i retract all previous
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It increases the arm length, so the actual bar moving inch per inch is less stiff than say that of the ASR bar (the 'stiffness decreases proportionally to something like 1/moment arm^3) ....BUT we aren't looking at the stiffness of the bar, we want to look at the stiffness of the bar at the wheel...
The actual stiffness of the bar at the wheel (ie wheel rate) is calculated using the following equation
wheel rate = spring rate (stiffness of the sway bar) / leverage of the wheel on the bar^2
So if we say that the moment arm increases at the same rate of the leverage increases, we can simplify this as:
delta wheel rate ~ distance ^ 1.666666
The actual stiffness of the bar at the wheel (ie wheel rate) is calculated using the following equation
wheel rate = spring rate (stiffness of the sway bar) / leverage of the wheel on the bar^2
So if we say that the moment arm increases at the same rate of the leverage increases, we can simplify this as:
delta wheel rate ~ distance ^ 1.666666
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yo malhon just a little off topic but i love your asr brace lov the color but your also running the 24mm asr bar as well correct?
im in the mist of wnating a upgrade sway bar from the stock gsr. Does anyone have a link to where i can purchase the itr 22mm or 23mm with bushings, also the link to ASR subframe.
Can i reuse my endlinks or do i need to upgrade for the bigger swaybar?
thanks
Can i reuse my endlinks or do i need to upgrade for the bigger swaybar?
thanks
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thats no his car, and IIRC he's on a 22 or 23mm barechelonwarrior on Feb/23/10 said:
If you wanting a 22mm rear sway it is cheapest to buy them from acura carland or delray depending where you located. I just calc. it and it is like 95 all new without shipping for bar, bushings, and brackets. Im talking to shop that has the rear 23 jdm itr and 25 mm front coming in and working on setting up a price. If you want more details pm me and i will let you know when i know._Crono_ on Feb/23/10 said:
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The subframe brace does nothing as far as stiffening anything up. I personally have a hard time justifying the price they want for that damn thing since it's just a flat piece of metal. I recommend looking in the intense learning suspension thread where I go over calculations pertaining to ride frequency/wheel rate and picking your ideal swaybar from there.
quick question; when putting on the asr 24mm bar, do you put the endlinks outside the bar with the bolt faceing the inside or is the endlink on the outside..
also which way is the endlink suppose to be? Theres two sides one side has a larger metal bolt and the other side of the enlink does;; which one is uppose to go on the lower control arms? (fyi im changing out the stock lca to blox lca).
just to clarify so i know what is correct when i put it on.
pics would help if anyone has clear shots of how they put theirs.
also which way is the endlink suppose to be? Theres two sides one side has a larger metal bolt and the other side of the enlink does;; which one is uppose to go on the lower control arms? (fyi im changing out the stock lca to blox lca).
just to clarify so i know what is correct when i put it on.
pics would help if anyone has clear shots of how they put theirs.
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Really doesn't matter as far as 'upside down' or not. You are going to want to put the bolt + endlink so when the car is sitting down, the endlinks are as vertical as possible.
do you have a good picture of it? im more of a visualizer; ive checked different forums and looked at different pictures; but no one really has a good clear shot of how it should be. I dont want to screw up the endlinks and be forced to buy new ones for installing it incorrectly if you know what i mean. anyways thanks Malhon!
SGT.
I have been trying to calc. my overall wheel rate factoring in my spring wheel rate and the effects of my sway bar.
I honestly do not understand how to use this formula to obtain my answer.[
The equation is taken from How To Make Your Car Handle by Fred Puhn and has proven itself fairly accurate:
500,000 D^4
K (lbs/in) = -------------------------------------
(0.4244 x A^2 x B) + (0.2264 x C^3)
B
_________________
A|/\ C
|/
A - Length of end perpendicular to B (torque arm - inches)
B - Length of center section (inches)
C - Length of end (inches)
D - Diameter bar (inches)
For hollow bars, we calculate the rate of a solid bar of the outer diameter and the rate of a solid bar of the inner diameter. Then, the rate of the smaller bar is subtracted from the larger bar.
I did not want to make a new post but maybe i should have future members.
I calculated my wheel rate from my skunk2 Pro coilovers (8k in front, 6 k in rear) at F 199.11 and R at 184.36 (this is using 1.5 for the front and 1.35 for the rear. I read that those are the wrong numbers and we should use the inverse but thats a side note)
I'm trying to factor in how upgrading my sway bars to achieve a overall more neutral felling.
MY PROBLEMS:
1. I do not have the measurements of A,B,C,D in the above equation to fill it in. (obviously i can calculate D easily, but I don't have a spare sway bar to measure the others)
2. I don't see how this valve factors with my previous wheel rates. Do you simply add your spring wheel rates to the values determined by the sway bar equation i posted above? Ex. Front 191.11 + K
Please try to answer this is simple terms, I'm not lazy and don't mind crunching numnbers but sometimes you jargon is aimed to other engineers it seems. Thank you very much.
I have been trying to calc. my overall wheel rate factoring in my spring wheel rate and the effects of my sway bar.
I honestly do not understand how to use this formula to obtain my answer.[
The equation is taken from How To Make Your Car Handle by Fred Puhn and has proven itself fairly accurate:
500,000 D^4
K (lbs/in) = -------------------------------------
(0.4244 x A^2 x B) + (0.2264 x C^3)
B
_________________
A|/\ C
|/
A - Length of end perpendicular to B (torque arm - inches)
B - Length of center section (inches)
C - Length of end (inches)
D - Diameter bar (inches)
For hollow bars, we calculate the rate of a solid bar of the outer diameter and the rate of a solid bar of the inner diameter. Then, the rate of the smaller bar is subtracted from the larger bar.
I did not want to make a new post but maybe i should have future members.
I calculated my wheel rate from my skunk2 Pro coilovers (8k in front, 6 k in rear) at F 199.11 and R at 184.36 (this is using 1.5 for the front and 1.35 for the rear. I read that those are the wrong numbers and we should use the inverse but thats a side note)
I'm trying to factor in how upgrading my sway bars to achieve a overall more neutral felling.
MY PROBLEMS:
1. I do not have the measurements of A,B,C,D in the above equation to fill it in. (obviously i can calculate D easily, but I don't have a spare sway bar to measure the others)
2. I don't see how this valve factors with my previous wheel rates. Do you simply add your spring wheel rates to the values determined by the sway bar equation i posted above? Ex. Front 191.11 + K
Please try to answer this is simple terms, I'm not lazy and don't mind crunching numnbers but sometimes you jargon is aimed to other engineers it seems. Thank you very much.
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Andrew, if I can jump in here...
1) get a tape measure
2) It's tough to add wheel rate from springs and wheel rate for a RSB, mainly because, well...it depends.
The formula you reference from Mr. Puhn, page 150 for anyone following along, is for calculating the stiffness provided by a RSB, the units are inches, which makes it tough to compare to your 199.11/184.36 However, the 500,000 that Fred uses as a proportionality constant probably has a set of unit coefficients to turn the formula to produce a stiffness (most likely angular) rating.
What are the units of your F/R roll stiffnesses anyway? If they're not the same, then you can't add them. If you can figure out the true units of Fred's Fig24 equation and can compare them to your wheel rates, then I think you can add them - I'd love to hear another viewpoint on this. Maybe Mr_Efficiency will chime in.
Keep in mind the inherent function of the springs vs. the RSB and how that might effect the nature in which they would "add" during function - ex. hitting a speedbump compresses springs, turning "compresses" roll bar.
This is most likely "new post worthy" IMO
1) get a tape measure
2) It's tough to add wheel rate from springs and wheel rate for a RSB, mainly because, well...it depends.
The formula you reference from Mr. Puhn, page 150 for anyone following along, is for calculating the stiffness provided by a RSB, the units are inches, which makes it tough to compare to your 199.11/184.36 However, the 500,000 that Fred uses as a proportionality constant probably has a set of unit coefficients to turn the formula to produce a stiffness (most likely angular) rating.
What are the units of your F/R roll stiffnesses anyway? If they're not the same, then you can't add them. If you can figure out the true units of Fred's Fig24 equation and can compare them to your wheel rates, then I think you can add them - I'd love to hear another viewpoint on this. Maybe Mr_Efficiency will chime in.
Keep in mind the inherent function of the springs vs. the RSB and how that might effect the nature in which they would "add" during function - ex. hitting a speedbump compresses springs, turning "compresses" roll bar.
This is most likely "new post worthy" IMO
Robb,
Thanks for the reply. I did not see it right away otherwise I would have replied. I know that i can measure my sway with a tape. Haha, but it is hard when you live in a apartment away from a garage, only have your car's jack and it is Freezing outside.
1.) My units for 199.11/184.36 should be pounds/inch. I figured this since the value MD posted (1.5, 1.35) where unitless and I assume a constant themselves. (constant in our integras of course)
2.) Your right about the 500,000 value, if K comes out unitless then 500,000 should contain all the unit values in order to cancel out. I will try to look into this more this weekend.
3.) The reason I ask all of this is because I'm trying to build a solid track/street car. I already have my coilover set up and really ant to avoid buying new ones. Additionally, the set up is somewhat soft enough to drive daily compared to 500lb/in set up others have. I have found JDM ITR sways 25 front and 23 rear for 190 shipped and was hoping that this set up would allow me to shift my cars weight onto the springs/ wheels early in the turn in therefore putting the maximum amount of weight to the tires and will still be able to absorb street bumps without launching the car into the air. (For example driving on the tail of the dragon where there are some bumps etc.)
4.) I'm not an expert on any of this and don't want to come off like an idiot but here are some examples of my overall thought. The springs are A and the sway bar is B. Driving straight and hitting a bump would compress A and my effective wheel rate would be 191 lb/in in the front. However in a turn, A would compress and B would resist the motion of the turn making my effective wheel rate = to A + (some coefficient)B. Granted common sense and knowledge of springs would say that the car cannot have a wheel rate greater than the rate from the spring since that is what is holds the car up, but since the sway bar would resist the motion and transfer of weight it could have an effect on the total wheel rate. You could say that the sway bar makes the amount of the weight transfer less. Similar to how lowering the weight of the car will increase its effective spring rate. (why the rear appears to ride more rough than the front).
Well I somewhat lost my place, I can retype all of this into a new thread of someone with a M beside there name would like me to. lol, (don't wanna double post!)
Thanks for the reply. I did not see it right away otherwise I would have replied. I know that i can measure my sway with a tape. Haha, but it is hard when you live in a apartment away from a garage, only have your car's jack and it is Freezing outside.
1.) My units for 199.11/184.36 should be pounds/inch. I figured this since the value MD posted (1.5, 1.35) where unitless and I assume a constant themselves. (constant in our integras of course)
2.) Your right about the 500,000 value, if K comes out unitless then 500,000 should contain all the unit values in order to cancel out. I will try to look into this more this weekend.
3.) The reason I ask all of this is because I'm trying to build a solid track/street car. I already have my coilover set up and really ant to avoid buying new ones. Additionally, the set up is somewhat soft enough to drive daily compared to 500lb/in set up others have. I have found JDM ITR sways 25 front and 23 rear for 190 shipped and was hoping that this set up would allow me to shift my cars weight onto the springs/ wheels early in the turn in therefore putting the maximum amount of weight to the tires and will still be able to absorb street bumps without launching the car into the air. (For example driving on the tail of the dragon where there are some bumps etc.)
4.) I'm not an expert on any of this and don't want to come off like an idiot but here are some examples of my overall thought. The springs are A and the sway bar is B. Driving straight and hitting a bump would compress A and my effective wheel rate would be 191 lb/in in the front. However in a turn, A would compress and B would resist the motion of the turn making my effective wheel rate = to A + (some coefficient)B. Granted common sense and knowledge of springs would say that the car cannot have a wheel rate greater than the rate from the spring since that is what is holds the car up, but since the sway bar would resist the motion and transfer of weight it could have an effect on the total wheel rate. You could say that the sway bar makes the amount of the weight transfer less. Similar to how lowering the weight of the car will increase its effective spring rate. (why the rear appears to ride more rough than the front).
Well I somewhat lost my place, I can retype all of this into a new thread of someone with a M beside there name would like me to. lol, (don't wanna double post!)
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5,178 Posts
not to sound like a noob but here goes. u say it doesnt stiffen the anything up meaning the subframe brace bt ive read that it acts as a lower tie bar... is this information incorrect?sgtmillhouse648 on Feb/23/10 said:
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Most everything you say here is correct regarding how the sway bar and springs act together, EXCEPT for the part I put in bold. Sway bars don't actually affect weight transfer, they only affect the rate of weight transfer.integrao on Feb/26/10 said:
How does lowering the CG of a car increase the effect spring rate? Are you referring to how lowing the roll center (not the CG) will decrease the effective roll rate from springs via and increased rolling moment?
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28 Posts
sorry to highjack this thread, but has anyone used
Beak - DC Quick Swap with OEM 22mm ITR
Progress - 62.1001 - 24mm
which one would be a better for a LS gen 3
Beak - DC Quick Swap with OEM 22mm ITR
Progress - 62.1001 - 24mm
which one would be a better for a LS gen 3
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