curls

So the moral of JTso's story:

Use lube, and use it often. No need for rings and collars and other stuff... just pure lube.

(you sickos!)

JTso

iTrader: (2)

The moral of the story is to leave good enough alone and don't mod your car!

Edit: btw, I personally don't think keeping the bushings lubed alone will eliminate the stress problem on the bracket by the larger bar. I guess time will tell...

JTso

iTrader: (2)

I think a good test of the lubrication theory would be coming from someone who tracks on a regular basis. vwong?

jwood_06TSX

Well first off, me being a structural engineer gives me hardly any addional knowledge about cars, just a little bit about physics and the like. I was just responding to Jan on that one....lol. Since i'm at work right now i can't respond to JTso with comments and questions now, but will do so later tonight.

You make a lot of good points and ask a lot of good questions, ones i have been asking myself actually. When i say keeping them lubed (extra lube for Eric ) i don't mean to use that a fix all solution. I know there is a large amount of added stress and it is very hard to measure (at least for us), which is a problem in itself. As for where that stress goes, how it gets there, and what is done to help carry it throughout other parts including the frame and probably mostly the frame, is what i would hope Comptech studied when designing the bar. Anyway, just a few thoughts and i'll try and get back to it tonight.

This is like an engineering problem to me.....i'll probably print out JTso's notes and read them on the train and makes notes on them....lol

jlukja

I need diagrams to go with the notes.

I guess the essence of what I am wondering is whether allowing the bar to move laterally through the bushings adds or relieves the stresses placed on the mounts. The design of the Progress bar (and what JTso wrote above) seems to indicate that lateral movement is not desirable, ergo the bump stops and collars. Intuitively, I would think that allowing the lateral movement would relieve the stress at the mounts (there goes my undergrad materials & structures class getting me in trouble). But, then that begs another question, are the location of the mounts/bushings designed as pivot points for when the bar flexes or are they just supports for the bar. The answer to that second question, I think, is key. Unfortunately it needs to be answered by someone who knows a lot more about suspension design than I do.

theElio

I'm another person with the cursed creaking/squeaking. I've got the Comptech RSB (rubber bushings & teflon tape) and Acura A-Spec suspension on currently. The noise was going on for about 4 months or so before I couldn't take it any more and got underneath the car. The right rear stabilizer link was cracked in half so I replaced the pair of stabilizer links and went for an alignment. (Rear left wheel is at -2.5 so I'm going to have to get a camber kit and re-align) This greatly reduced the noise for the past 2 weeks or so, but it's starting to come back. I just found this thread so it's scaring me into going stock or potentially Progress. I love the handling of the Comptech RSB (before the creaking) but I'm getting frustrated with all the annoyances because of it.
If I get home before the sun goes down, I'm going to raise the car and check the mount to see if it's not broken as well. Is there a link to some of that high temp lithium grease you guys are touting so I can buy it easily?
However, it's tempting to just buy the Progress bar and install it in Comptech's place. I'm getting frustrated but don't want to burn a hole in my wallet. Advice?

JTso

iTrader: (2)

I think the primary use of the stopper rings or collars on the bar is to allow the bar to be stationary in order to provide the maximum effect on torsion control. However, this could also mean increased stress on the bushing mounting points as they are placed very closedly together... This is an interesting topic.

jwood_06TSX

That is what i was thinking and its also what Jan was leaning towards as well (with his material and structure undergrad days...lol). If you put those collars on the bar and take away most of that side to side motion, i would tend to think that stress produced on a turn that would normal be distributed to the frame and the other side of the car, is now left with more of the stress being translated to the frame since the bar is not moving side to side as much. Your right JTso, this is very interesting and i'm going read your post again on the train ride home

xjohnkdoex

iTrader: (2)

but why aren't the frame mounts breaking for progress users and, instead, breaking with the comptech users?

i'm sure there are a lot more variables involved, but it doesn't seem like this is an issue w/ the progress bar? or has no one had it installed long enough to incur this kind of damage?

jwood_06TSX

There are a lot more variables to this then most people realize. There have only been 2 people that i'm aware of the comptech breaking and i'm not sure how long other people have had the progress one, but i don't think its been out as long (don't quote me on that, the old head can attest to that). The progress also isn't as large of an increase in size as comptech.

JTso

iTrader: (2)

I guess having the collars is not a bad thing as long as the mounting points are strong enough to handle the potential increased stress. Therefore, here is another point for discussion. If the bar can be made more effective by using the collars, then it would control the weight shift/transfer much better and quicker. If the weight shift/transfer can be better maintained, doesn't it means less stress on the supporting components as the bar would take less time stablizing the car, instead of fighting it with a less effective system?

JTso

iTrader: (2)

The Progress is the same size as the Comptech at 22mm. Neuspeed is 19mm.

jwood_06TSX

DOH!....i got them mixed up...lol. Good question and possible point above too....

My thinking cap will go on in a little bit...hah

jlukja

Good question. Is it the design difference or the smaller sample size? I suspect there have been more CT bars in use than Progress, and we've only had 2 (or 3) instances of failure.

jlukja

We need an automotive suspension design engineer. Isn't one of our newer members a race car driver? Maybe we can ask him to forward this question to one of his crew?

BulldogHockey

Lack of grease is likely your problem as you're suggesting. You can get it in a tube just about anywhere (Autozone, NAPA, etc.). I had the Teflon tape also, and had major noises that were driving me crazy. I installed the Energy Suspension bushings with the grease zerks and the problem is 100% gone. There are links to that in past posts. You'll also find out they need to be modified (takes maybe 30 minutes), but getting under the car and greasing the bushing in 5 minutes without jacking it up makes it all worthwhile. If you go that route, get a right angle grease gun coupler, because one of them seems impossible to grease with the close proximimity to exhaust pipe.

And back to the topic at hand, I think keeping the bar from binding in the bushings (lubed up) is going to help out a lot. As jlukja suggested, the sample size for Progress is likely smaller and has less field time. Might be a little premature to start removing Comptech bars and switch to Progress

jwood_06TSX

I was going to do this last night but wasn’t able to and so I did it this morning so forgive me if some of my sentences don’t make sense….mornings are always rough for me….lol
Lets go back to basics and break it down slowly. The sway bar is solidly connected to the frame and the two end-links which are connected to the lower suspension arms. When the car corners, it leans over according to the center of mass being cantilevered out. This causes one spring to compress and the other to extend. This usually overloads the cornering tire and causes it to "roll-under." The flatter a car is the better, for handling purposes anyway. The torsional force that a sway bar can take is limited by the modulus of the material. The diameter of the bar and the length (and angle) of the "arms" determine the "stiffness" of the bar. When going over a speed bump evenly with both tires will not use the capabilities of the sway bar because both ends rotate up and down simultaneously = no twisting involved.

JTso’s questions are in bold:

What is the primpary use of lubrication on a swaybar bushing? There isn't a single drop of lube on OEM soft rubber bushings on any cars regardless of how large the dia of the bar. You will only see the application of lube on poly bushing to eliminate noise due to the tight clearance, or lack there of between the bar and bushings. Otherwise, the dealer will have huge amount of squeaky suspension problem calls, or swaybar lubrication would be one of the regular maintenance items.
This is a good question and I’m still not exactly sure why there is no lubrication. I haven’t seen or touched these poly bushings yet (I used the comptech ones) that some are using but my guess would be that from a material stand point, then are denser material. So, since they won’t flex as much or “give” as much as the stock seem to, then that is the need for lube. However, if you look at how much body roll is on a stock TSX, the stock dampers take some of that stress transfer and the bar has much more torsional movement (due to the spring rates as well). Since these dampers and springs are “softer” and “give” more, I would tend to think they are helping take that stress that get transferred through the bar. However, when you go to an aftermarket suspension with stiffer spring rates, they don’t “give” as much. They can transfer the stress but the bar will not be rotating as much since the car itself isn’t leaning out as much. If the bar isn’t rotating as much, it would need to be able to move as much as possible to help transfer that stress….ie. lube in the bushings. Either way you look at it, it will be creating more stress on those mounts.

Why use poly bushings? We all know the primpary use of poly bushing is to eliminate the flex in the system so the swaybar will react more quickly during turns. However, this also means quicker transfer of stress to the rest of the system (brackets, endlinks).
Again, exactly right. Getting a harder material like the poly bushings will take even more of that flex away creating a need for the lubrication. The stress is def being transferred faster, you are 100% correct. This is the part that I’m not 100% sure about because I don’t know exactly what parts are taking what portion of the stress. I would tend to think that the end links are what would break before anything else because if you have stiffer springs/dampers and a thicker bar, that stress is flying through the bar to the end link which then transfers it to the springs/dampers.

How does poly compare to OEM bushing in terms of rate of stress transfer? Let me provide an example hopefully makes some sense (or not). Imagine placing your finger through the opening of a OEM D-bushing. Now place the D-bushing with your finger in it between a bench vise. Now slowly tighten the bench vise until you start to feel the pain (stress). The rubber bushing will collaspe to a certain point until the give is taken up, then your finger will hurt like hell. The swaybar will compress the bushing the same way. Note the thin upper portion of the Comptech bushings are tore to hell in no time? Comptech later switched to a thicker bushing because of this reason. Now, repeat the same exercise with a poly bushing and see the difference.
I don’t know if the sway bar is going to be compressing the bar quite like that. That is a straight compression (the vice) with no tension involved and no torsion involved. The compression is def more significant but not direct compression. It is more a combination of compression and shearing that makes them turn out like that, which is why you want the lubrication. This will allow less friction between that transferring of the torsional type force from the bar to the frame and to the other side of the car.


Why do poly bushings require maintenance (lubrication)? Well, if the lube doesn't disappear, you will never have to re-lube the bushings. But how do they disappear? Well, the rotating movement will squeeze some of them out, and the side-to-side movement will cause some of it to come out as well, covering the side of the bushings. The amount of lube loss can not be recovered even the bar slides back to the original position. The bushings will simple push it aside due to the tight clearance. Now, what if the side movement of the bar can be reduced? Does it help reduce lubrication loss and thus increase the maintenane cycle? Perhaps.
I agree with this 100%. I honestly don’t think we want to reduce the side to side movement. If that bar is not moving a little side to side (ie, no lubrication or split collar = more stress on the bushings which connects to the frame), it will create a larger stress that is unwanted.


How to reduce the side movement? Progress seems to have a good idea on how to do it. In fact, Progress also uses the split collar on swaybars for other cars.
If we put a split collar on this to prevent side to side motion here is what I think will happen. When the car turns or leans, that bar is going to move a little with it. If it can’t move at all because that split collar is clamped onto the bar right next to the mount, the stress of the car lean is going to be exerted on now the collar and the mount. So maybe, it may even take some stress of the mount however, it might add to the stress in a different location which in the end, may even cause more damage. I tried to show what i mean here but its hard to uner stand because its actually almost creating a moment around the mount which would be a lot more stress than we would want.





Does the side movement increase or decrease stress on the brackets? Well, if movement promotes lubrication loss, and loss of lubrication promotes stress on the brackets... Then, what do you think?
Exactly, so you would creat less side to side movement with the split collar and decrease the need to lube the bushings, but are you actually creating more stress on the mount…..i am leaning towards yes….


Are the OEM swaybar brackets capable of handling a larger bar like the one for the TSX (22mm)? The size increase from 15mm to 22mm is huge. The 7mm increase with a solid bar can exert large amount of stress. I think someone has provided some data on that.
I saw that data you are talking about, it was 320% stiffer or something like that. In all honest this is part that will depend on your driving style, and total performance package. I’m not sure exactly how all this fits together as in, do you want higher or lower spring rates to help absorb the stress or visa versa. However, the mounts were not designed for this large of a bar IMO, and if you look at the welds, there really isn’t too much there :/


I happen to be installing a new Progress rear swaybar for my Prelude yesterday. The OEM bar is 23mm and the new bar is 27mm, which is a much smaller increase than the TSX bar (4mm vs 7mm). However, Progress includes a set of heavy duty brackets measure 4.6mm thick and extended the base of the bracket to another few inches to provide more support and adding another mounting hole on the base bracket. Additionally, Progress also offers a replacement set of all metal rod end endlinks to be used with the 27mm bar. All these extra steps are clear indications how much stress can be put on the brackets with a thicker bar.
I think that also has to with the difference in performance of the Prelude to the TSX. I’m not familiar with the Prelude but I think it would be driven harder than a TSX and probably has a stiffer suspension to begin with. However, the fact they are providing those parts, does show that they did research to find out the difference in stress. Again however, the mounts might be better than on the TSX….are they? If you look at other forums, there are people breaking sway bar brackets all the time and then upgrading them, but not many mounts break. This is starting to lead me to think that no matter what lubrication, how often, or the like, that our mounts are just designed to handle HEAVY load. Again, I think this has largely to do with driving style and we would need some that drives track every once and while to check and report!

Why didn't Progress or Comptech include a different set of brackets? I believe they would if they could and should. If you examine the OEM brackets, it's not something that can be easily swapped out like other cars. Neuspeed took another approach which uses a slightly smaller bar (19mm).
I thought the Comptech one came with the gold color brackets?


MY FINAL THOUGHTS and SUMMARY oh what i really believe all this to sum up to-

I actually just talked this over with one of my head Structural PE's (Professional Engineer) and he agreed with me. The whole suspension works as a flexible unit in all cars, some more flexible than others like i mentioned above about ours having more body roll. These mounts (and other parts) weren't designed with such heavy modification in mind. It you look at the system as a whole that gsclifton had, he had the Tanabe coilovers with the CT sway bar and the poly bushings. That system took a rather "flexible" system and maybe it a much stiffer system. So where the stock system would transfer the stress from one side to the other with little interferance, it now has a stiffer bar, a stiffer bushings, and a stiffer shock. The structure as a whole (the car) is now a much more rigid body. Just like when i design a bridge connection, if the connection plate is not beefy enough to support the load that will be applied to it, then i need to beef up the connection plate, bolt, or weld in our case. Therefore, if you apply yet another object to the system that will yet again increase rigidity (the split collar) it will make it more stiff and in turn creating even more force in those areas. This is why you want to have as much lubrication there as possible. It is by no means going to solve your problem it may just increase the inevitable. Even if you weld some extra plates in there and beef it up, there is still something else that has to take that stress. The endlinks may be next, the bolts, or even the bushing brackets. Either way, there is no set solution to this and it is a do at your own risk. Again, i have been saying this over and over and over again, it also greatly depends on your driving style. If you constantly take corners harder or high speed on and off ramps and such, then you will be putting more stress on the car as a whole (obviously). I think it also depends on the overall system you have as well. the stiffer stuff you got, the more rigid it will be. So for some one with Tien Basics (100% stiffer), CT sway bar (320% stiffer), and poly bushings (not sure but say probably 100% stiffer) you are looking a system that is now 520% stiffer!! Yes the car is fun, yes i am leaving mine on there with my aspec kit, and yes i'm doing it at my own risk however, i don't drive it that hard, i keep them WELL lubricated and i check conitunally. You will be able to see the steel fatiguing prior to it breaking, so check it often if your worried about it. Thats all folks

jwood_06TSX

Just a side note too btw, that is not really how you calculate the total stiffness increase, i was just doing that to show a representation of what all is affecting it by how much. To calculate it you usually take the inverse of the stresses, at least in bridges we do.....lol. If i calculate it the way we do then its actually 1/100 + 1/100 +1/320 = 1/520 = .023125 and then inverse of that so 1/.023125 = 43.24%. Therefore, for a quick estimate, car weight = 3000lbs (just say) 1500lbs on the rear 750lbs per tire. When moving and turning the weight needs to move and get transfered but now the car as a whole is 43.24% stiffer in the rear......you can figure out the rest

JTso

iTrader: (2)

I was actually referring to the bracket where the D-bushing mounts on (the one that breaks), not the D-bushing bracket that goes over the bushing.

Progress includes the entire mounting bracket assemby set with my Prelude RSB. The D-bushing mounting point on the TSX is part of the lower subframe which is not a bolt-on item.

We forgot to mention another factor - tires. A larger bar will also put more stress on the tires while trying to stablizing the weight of the car during cornering. Poor tires will give a little or slide during hard cornering as the result of adding a larger bar. If the same car is equiped with much better and stickier tires to resist sliding during cornering, that puts the stress back on the rest of swaybar mounting points. Doesn't it look like the OEM rubber bushing and poly bushing comparison we did earlier (less give = more stress)?

Edit: just fixed my numerous typos.

curls

It was I who did the comparison of stiffness from OEM bar to CT 22mm bar, and the calculation was for (pardon my non-tecnhical term useage here) "torsional rigidity", and assumed equal construction (solid=solid, hollow=hollow, bends in the same place, etc...).

Here's a calculation I found that provides the twist (or lack thereof) for a sway bar:
twist = (2 x torque x length) / (pi x diam^4 x material modulus)

Assuming equal construction (length of torque arm, material modulus, and overall length) for simplicity, the calculation for %increase in stiffness for a 22mm vs a 15mm (stock) bar is:
(22^4) / (15^4) = 234256 / 50625 = 4.627 = 363% stiffer.

jwood_06TSX

HAHA....JTso, i totally wasn't even thinking about the tires but take NASCAR for example. Those cars have pretty much 0 body roll and are as stiff as you can get, but look how fast they go through tires! Given, we don't drive like that on a regular basis but the tires are designed differently and such. But yes, i believe your right. So taking my example before it would 100% for Basics, probably only like 50% for the bushings (i doubt it would a full 100%), 363% for the bar itself, and the tires, i wouldn't really know how to determine that. But if you look at most setups people have, they put thinner tires with less give which in turn will take less of the stress. The thought though of those split collar really just makes me think it would now be creating a moment at the mount, which would not be good. There is already enough stress moving through there, you need that little bit of motion with the lubrication in there to give it SOME flexiblness. However, if you already have a heavy duty setup like, Tien Flex, 18" or 19" tires, any sway bar, and poly bushings, i doubt the split collar is going to put you over the top.....or could it?!?....lol



Eric- I think you calculated it correctly except for the fact that the odds of the modulous of the materials probably isn't the same. It still wouldn't be significant enough to change it by that much, but nontheless Can you just explain your math for going from 4.627 to the 363%.....just want to check something..

curls

1.00=equal=0% increase.

So 4.627 - 1.00 = 3.627 = 362.7% increase over stock (rounded up to 363%).

vidgamer

Using that same formula, a 19mm bar (Neuspeed) would be 2.574 or 154% increase over stock. That's over twice as stiff, which I would think is still significant, but hopefully will result in less stress than the thicker bars. (Well, I hope it's a good idea, since that's the one I got! )

About using actual race cars for an example, this isn't related to what was said, but the thought occurred to me that race cars don't have to deal with potholes and all sorts of irregularities like we do on the street. I like a sportier ride, but it still needs to be compliant enough to soak up some bumps!

jlukja

The creaking/squeaking returned about a month ago. Today being a nice warm day, I was able to take the bushings off, clean and re-lube them, and put them back on. This time I used white lithium grease instead of the lube that came with the bushings. The creaking/squeaking went away.

I also carefully inspected the RSB mounts for cracks or any other indication that they would break. I'm relieved and happy to say that everything looked good.

cwinterrowd

Has anyone tried adjustable endlinks to reduce or negatively load the RSB to avoid putting too much stress on the mounts? I just installed the Progress RSB + Fastline Adjustable endlinks and I did my best to neutralize the loading (with weights in the drivers seat equivalent to my weight) in hopes that I don't break the mounts if I get carried away on a nice twisty mountain road.

I'm curious if this would help reduce some of the stress on the mounts, while I watch and wait for Mr. Heeltoe's project to deliver a subframe reinforcement system and thicker RSB.

feuss2

iTrader: (1)

I will pay shipping if you send it to me!!!

GSGOMEZ

Hey my wife heard noise under right rear passenger and I did inspected it. I just found it out that bar mount cracked at same picture showed here. I was figure it out how to fix the bar mount? Should I remove the sway bar or leave it there until bar mount fix? I have to call welding and see if they can fix it. I have Progress sway bar on my 94 Honda Accord and sway bar installation is much better and strong support than Acura TSX sway bar because Progress come with hard bracket and some parts to support the sway bar. Any suggestions?

Thanks,
George

MNTSX07

GSGOMEZ do you have a Progress sway bar on the TSX with the cracked mount or is it another brand? How long have you had it on and what year is the vehicle? Did you lube it frequently (twice a year)? I am about to put the Progress RSB on my 07 and am worried that I will experience similar problems. Anyone with a Progress RSB had a cracked mount?

Simba91102

I've been following this issue for a few years (note the date on the beginning post of this thread) and so far, I haven't seen any reports of broken mounts with the Progress bar. It appears that the Comptech bar with the poly bushings seems to be the only one involved with the broken mounts. I'm not saying it can't or hasn't happened with another rear sway bar, I just haven't seen any report of it here. And it appears to be rare, though I wouldn't use the Comptech bar because of it (I have a Progress rear sway bar, but installed it before I was aware of the broken mount issue).

GSGOMEZ

No, I have Comptech sway bar on 04 TSX and did put lube it when it installed. I didn't realized that you said to put lube twice a year. But I have that car for 5 years since happened now. I have Progress on my 94 Honda Accord and seems that Progress is better quality than Comptech. I called the welding shop and they can fix it on bar mounting but TSX bar mounting seems not strong to support 22mm sway bar. I told them that bar mount needs to be strong. They need to take look and check it out.

GSGOMEZ

I agree with you!!!

vthree

iTrader: (1)

doh add me to the bunch. mine broke as well.

same side too. passenger.

same exact spot broke off... and looks like i don't have much of a resolution to run to... =/