Swaybar comparison (assumptions?)
- Thread starter Shaun
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Re: Swaybar comparison (assumptions?)
Good issue raised.
Since ARBs' main job is to handle roll resistance, I would suppose the diameter and weight of the bar has the greatest effect.
My first question will always be the weight of bar vs roll resistance, given that most of us do not know the material used hence the twisting strength of the ARB. I always have the impression that (a) a larger bar diameter (b) a heavier ARB works better.
Second question is - is there an optimal diameter (and hence weight)? Clearly, if my assumptions are correct, too great a diameter and the car will be so stiff and tyres will lose traction. So there must be an optimal figure. How do we determine that?
Good issue raised.
Since ARBs' main job is to handle roll resistance, I would suppose the diameter and weight of the bar has the greatest effect.
My first question will always be the weight of bar vs roll resistance, given that most of us do not know the material used hence the twisting strength of the ARB. I always have the impression that (a) a larger bar diameter (b) a heavier ARB works better.
Second question is - is there an optimal diameter (and hence weight)? Clearly, if my assumptions are correct, too great a diameter and the car will be so stiff and tyres will lose traction. So there must be an optimal figure. How do we determine that?
powersteer
Well-Known Member
Re: Swaybar comparison (assumptions?)
it depends on the objective of the exercise.
some peeps change the roll bars to tweak their chassis balance
others merely use them to reduce the roll angle ... as long as they dun use up the tractions provided by the tyres, they dun step into the danger zone
it depends on the objective of the exercise.
some peeps change the roll bars to tweak their chassis balance
others merely use them to reduce the roll angle ... as long as they dun use up the tractions provided by the tyres, they dun step into the danger zone
Re: Swaybar comparison (assumptions?)
Even ignoring overall optimization and just focusing on bars alone, I don't really see how one can shine over another assuming roughly the same amount of time and money has been put into creating both. They're not a complex part and fulfill a simple role.
It's like saying. "oh that grade 5 bolt by ABC is probably not going to be better than a grade 5 bolt by XYZ." The thing is, they're not complex to make, and they're both grade 5 bolts so differentiation is minimal
But maybe there are some real strong reasons for Hotchkis being better than H&R? It would be good to hear.
Even ignoring overall optimization and just focusing on bars alone, I don't really see how one can shine over another assuming roughly the same amount of time and money has been put into creating both. They're not a complex part and fulfill a simple role.
It's like saying. "oh that grade 5 bolt by ABC is probably not going to be better than a grade 5 bolt by XYZ." The thing is, they're not complex to make, and they're both grade 5 bolts so differentiation is minimal
But maybe there are some real strong reasons for Hotchkis being better than H&R? It would be good to hear.
Re: Swaybar comparison (assumptions?)
Would listing a list of parameters and then quantitatively comparing the various brands be sufficient for the laymen? Example - listing diameter as one variable and comparing diameters of various brands. Else, it would be like comparing shampoos on the shelves when making purchase decisions.Shaun said:
Re: Swaybar comparison (assumptions?)
Shaun, I'm not as technical as you. I use what you call the "butt dyno". I have sat in the same ride using the H&R. I did my fair share of homework before I bought something that may seem cheap to you but not to me. The drive, like I said, is essentially different and changed the nature of the ride altogether.
Just size alone, the 27mm front and back for the Hotchkis compared to the 24/28 or 22/26, did well enough to convince me. And for a superficial girl like me, it looks good. But what sold me was the adjustable stiffness that could allow my car to behave more like a RWD, stiffer towards the rear.
Shaun, I'm not as technical as you. I use what you call the "butt dyno". I have sat in the same ride using the H&R. I did my fair share of homework before I bought something that may seem cheap to you but not to me. The drive, like I said, is essentially different and changed the nature of the ride altogether.
Just size alone, the 27mm front and back for the Hotchkis compared to the 24/28 or 22/26, did well enough to convince me. And for a superficial girl like me, it looks good. But what sold me was the adjustable stiffness that could allow my car to behave more like a RWD, stiffer towards the rear.
Re: Swaybar comparison (assumptions?)
?? FP I think you missed the point. That ARBs can improve handling was never questioned, so no one is questioning your butt dyno. ARBs almost always improve handling in the street car context, so no one is questioning any of that, or you love for your car, or the fun it brings. I may be getting ARBs soon too, which was part of why I asked.
I was asking for specific comparison between Hotchkis and H&R, because you specifically stated that you didn't think H&R could be as good, which made me wonder why because like I said, they are a simple part performing a simple function.
==
So far you've mentioned bar diameter and adjustability. AFAIK, H&R features the same adjustability you mention, which leaves bar size. You are right in that 27mm F and R would almost certainly help move your car more away from understeer vs H&R available options that still bias towards the front.
So yah, if the right sizing options (unavailable from H&R) for Hotchkis were available for your model to move it better in the direction you wanted to take it, that's a perfect reason. I don't get what all the drama was about.
FWIW, sizing steps aside, I don't see any reason why H&R wouldn't be able to make a bar as good or better than Hotchkis. There are other reasons why H&R might have chosen the front biased bar ratios, but those can come some other time.
?? FP I think you missed the point. That ARBs can improve handling was never questioned, so no one is questioning your butt dyno. ARBs almost always improve handling in the street car context, so no one is questioning any of that, or you love for your car, or the fun it brings. I may be getting ARBs soon too, which was part of why I asked.
I was asking for specific comparison between Hotchkis and H&R, because you specifically stated that you didn't think H&R could be as good, which made me wonder why because like I said, they are a simple part performing a simple function.
==
So far you've mentioned bar diameter and adjustability. AFAIK, H&R features the same adjustability you mention, which leaves bar size. You are right in that 27mm F and R would almost certainly help move your car more away from understeer vs H&R available options that still bias towards the front.
So yah, if the right sizing options (unavailable from H&R) for Hotchkis were available for your model to move it better in the direction you wanted to take it, that's a perfect reason. I don't get what all the drama was about.
FWIW, sizing steps aside, I don't see any reason why H&R wouldn't be able to make a bar as good or better than Hotchkis. There are other reasons why H&R might have chosen the front biased bar ratios, but those can come some other time.
powersteer
Well-Known Member
Re: Swaybar comparison (assumptions?)
i've seen cars with sheared / tore subframes from upgrading ARBs .... juz curious whether this has ever happened to Beemer?
i've seen cars with sheared / tore subframes from upgrading ARBs .... juz curious whether this has ever happened to Beemer?
Re: Swaybar comparison (assumptions?)
I know that ARBs that are too thick and stiff would cause that sheared / tore subframes but only under very hard driving or on a bumpy and pothole filled road. This is where the strain gets transferred to the subframes. Also, changing the ARBs does make the ride very tight and nice but on hard corners, I have realised that you are not able to carry as much speed as you would otherwise on a stock ARBs which are designed from factory. Just my experience this far. Hope it helps to some extent.
powersteer;383245 said:
I know that ARBs that are too thick and stiff would cause that sheared / tore subframes but only under very hard driving or on a bumpy and pothole filled road. This is where the strain gets transferred to the subframes. Also, changing the ARBs does make the ride very tight and nice but on hard corners, I have realised that you are not able to carry as much speed as you would otherwise on a stock ARBs which are designed from factory. Just my experience this far. Hope it helps to some extent.
Re: Swaybar comparison (assumptions?)
I don't think that would happen unless the base car was kind of flimsy, or tire widths or weight distributions of the stock car were radically changed that required very large spring or bar stagger (F to R), or a little of both. What car did you see it happen on? And how crazy a car was it? Usually cars that require crazy setups totally different from stock, don't function very well unless whoever is running it really knows what he's doing.
If that happens then you've crossed over into stiffness to high for the given surface - skipping across instead of tracking the ground. Even on a perfectly smooth surface, the speed of load transfer affects tire grip, temp, and life, but in a less obvious way vs a bumpy street surface or road course. ARBs also reduce the independence between the the L and R wheel pairs by tying them together. If you upset the rear inner wheel in a turn by hitting a bump or curb, it will try harder to upset the heavily loaded rear outer wheel and the car will lose traction easier. The fewer and smaller the single wheel bumps on a course, the less of a consideration this is.
Above are things that happen on one side of the ARB stiffness curve, but the other side is full of positives (better tire patch presented to ground, immediacy of response to inputs, better balance after tweaking it with different bar stiffness ratios ) that have been written about before and elsewhere. Most stockish street cars, especially the semi luxury ones fall quite far on the soft side and almost always benefit from moderate bar increases in terms of handling (at the expense of ride on uneven roads, but the roads in singapore are pretty smooth so no worries). With most street cars it would take something pretty extreme before crossing into the negative area, but I agree with you that stiffer isn't always better.
powersteer;383245 said:
I don't think that would happen unless the base car was kind of flimsy, or tire widths or weight distributions of the stock car were radically changed that required very large spring or bar stagger (F to R), or a little of both. What car did you see it happen on? And how crazy a car was it? Usually cars that require crazy setups totally different from stock, don't function very well unless whoever is running it really knows what he's doing.
elmariachi said:
If that happens then you've crossed over into stiffness to high for the given surface - skipping across instead of tracking the ground. Even on a perfectly smooth surface, the speed of load transfer affects tire grip, temp, and life, but in a less obvious way vs a bumpy street surface or road course. ARBs also reduce the independence between the the L and R wheel pairs by tying them together. If you upset the rear inner wheel in a turn by hitting a bump or curb, it will try harder to upset the heavily loaded rear outer wheel and the car will lose traction easier. The fewer and smaller the single wheel bumps on a course, the less of a consideration this is.
Above are things that happen on one side of the ARB stiffness curve, but the other side is full of positives (better tire patch presented to ground, immediacy of response to inputs, better balance after tweaking it with different bar stiffness ratios ) that have been written about before and elsewhere. Most stockish street cars, especially the semi luxury ones fall quite far on the soft side and almost always benefit from moderate bar increases in terms of handling (at the expense of ride on uneven roads, but the roads in singapore are pretty smooth so no worries). With most street cars it would take something pretty extreme before crossing into the negative area, but I agree with you that stiffer isn't always better.
Re: Swaybar comparison (assumptions?)
ARB properties and function are simple. How ARBs integrate with other systems with trying to optimize the overall vehicle is not so simple. Both are related to the topic. If you have nothing to add, there's no need to read or post.
ARB discussion has nothing to do with you racing anyone. Racing in unequal street cars is a pure waste of time. If you're such a hotshoe and want to go around challenging people, go join a first-step racing series and see where you end up. You might do decent, but probably not, because people that talk like you never do.
ARB properties and function are simple. How ARBs integrate with other systems with trying to optimize the overall vehicle is not so simple. Both are related to the topic. If you have nothing to add, there's no need to read or post.
ARB discussion has nothing to do with you racing anyone. Racing in unequal street cars is a pure waste of time. If you're such a hotshoe and want to go around challenging people, go join a first-step racing series and see where you end up. You might do decent, but probably not, because people that talk like you never do.
Re: Swaybar comparison (assumptions?)
Everything I've wondered I've asked plainly. The response was irrational and emotional, as is the follow up by you guys. It makes me think that perhaps there was hidden motive in the original claim that was questioned, and therefore the fear of it being revealed. This would explain the (continued) over reaction.
SHAMELESS;383534 said:
Everything I've wondered I've asked plainly. The response was irrational and emotional, as is the follow up by you guys. It makes me think that perhaps there was hidden motive in the original claim that was questioned, and therefore the fear of it being revealed. This would explain the (continued) over reaction.
Re: Swaybar comparison (assumptions?)
You too miss the point, worse still after it has been explained - and that is.. butt feel was never questioned. Only the brand comparison was. See quote below..
Butt feel is fine, there's nothing technical about how bars may not come in the right sizes or size combinations, and/or at a different pricet, better bushings, lower weight etc.
A simple question deserves a simple answer, not some some wild emotional barrage that is further followed up by others with approaches almost as irrational. A product should stand on its own merit. Other products should only be put down on real and valid points.
Still waiting for a formal accusation re: agenda. Or is there an inability to put one together in the knowledge that it does not exist?
You too miss the point, worse still after it has been explained - and that is.. butt feel was never questioned. Only the brand comparison was. See quote below..
Shaun said:
Butt feel is fine, there's nothing technical about how bars may not come in the right sizes or size combinations, and/or at a different pricet, better bushings, lower weight etc.
A simple question deserves a simple answer, not some some wild emotional barrage that is further followed up by others with approaches almost as irrational. A product should stand on its own merit. Other products should only be put down on real and valid points.
Still waiting for a formal accusation re: agenda. Or is there an inability to put one together in the knowledge that it does not exist?
Re: Swaybar comparison (assumptions?)
How do we, as laymen, compare ARBs? Assuming diameter is the most obvious measurable dimension in evaluating ARB (cause clearly it is the most direct input in determining stiffness, besides material used), is that any optimal diameter we are looking at relative to kerb weight, for instance? I mean, how do we ascertain that 27mm is the best diameter? What if there is a 29 mm version? Example, for a 1.6-ton E90, what is the optimal diameter? For E60?
How do we know how each mm increases the stiffness of the car relative to stock ARBs in % terms?
I realised that no one has directly answered my question.kenntona said:
How do we, as laymen, compare ARBs? Assuming diameter is the most obvious measurable dimension in evaluating ARB (cause clearly it is the most direct input in determining stiffness, besides material used), is that any optimal diameter we are looking at relative to kerb weight, for instance? I mean, how do we ascertain that 27mm is the best diameter? What if there is a 29 mm version? Example, for a 1.6-ton E90, what is the optimal diameter? For E60?
How do we know how each mm increases the stiffness of the car relative to stock ARBs in % terms?
Crufty Dusty
Well-Known Member
Re: Swaybar comparison (assumptions?)
Shaun is pointing out a logical fallacy (non-sequitur) which is pretty common even among extremely intelligent people. Doubt there is any hidden agenda because the question is valid since performance can be quantified and is not entirely subjective.
If the reply was something to the effect of "I like ABC company's ARB because it is the only available one in hot pink and that's my favorite color" then I guess it would not have ruffled any feathers since everyone has their own favorite color.
But when someone says "ABC company's ARB is better because of my butt dyno" then you'd probably have to be:
a) An authority on the subject (suspension expert)
b) Have a lot of data to substantiate your position and thus prove the worth of your butt dyno
Because that is a pretty bold claim and reviews to any degree will have positive and/or negative effects for all products mentioned, whether end-user, vendor etc. We're talking about livelihoods in some cases here.
Shaun is pointing out a logical fallacy (non-sequitur) which is pretty common even among extremely intelligent people. Doubt there is any hidden agenda because the question is valid since performance can be quantified and is not entirely subjective.
If the reply was something to the effect of "I like ABC company's ARB because it is the only available one in hot pink and that's my favorite color" then I guess it would not have ruffled any feathers since everyone has their own favorite color.
But when someone says "ABC company's ARB is better because of my butt dyno" then you'd probably have to be:
a) An authority on the subject (suspension expert)
b) Have a lot of data to substantiate your position and thus prove the worth of your butt dyno
Because that is a pretty bold claim and reviews to any degree will have positive and/or negative effects for all products mentioned, whether end-user, vendor etc. We're talking about livelihoods in some cases here.
Re: Swaybar comparison (assumptions?)
It varies from model to model and what the owner is trying to do with the car, surfaces driven over, and what the owner will tolerate and the type of driver he is. There is no general optimal because it comes down to some fine specifics. The amount of time required for measurement and calculation is not worth it for the enthusiast, and for his targets trial and error will come out ahead both time and cost wise. Efficiency and optimization is usually pretty low on street car list of priorities also because to really achieve it costs a disproportionate amount of money and time. If you're talking about racing then it is different, but that doesn't apply here.
kenntona;383594 said:
It varies from model to model and what the owner is trying to do with the car, surfaces driven over, and what the owner will tolerate and the type of driver he is. There is no general optimal because it comes down to some fine specifics. The amount of time required for measurement and calculation is not worth it for the enthusiast, and for his targets trial and error will come out ahead both time and cost wise. Efficiency and optimization is usually pretty low on street car list of priorities also because to really achieve it costs a disproportionate amount of money and time. If you're talking about racing then it is different, but that doesn't apply here.
