From past readings, and here on NAM, I was under the belief that the sway bar ends (where the end or drop-links connect) should ideally be parallel to the ground.

Visualizing the dynamics of what's going-on, it does seem to make sense. Thinking of our rear sway bar, we don't want the bar end at let's say 1 o'clock or 5 o'clock (view through the wheel, driver side); but rather 3 o'clock. Hope that makes sense...

For those with lowered MINI's, this does get altered, and is one of the reasons some will then go with adjustable links. Well, I've done just that (only in the rear now), and with the links at nearly full minimum, I'm still "above" 3 o'clock, and going the last thread or so, will not get me there, by my estimation...

Here's a photo of what I mean (clicking on it should make it bigger, if needed):



As you can see, the car is not overly lowered either...

I'm not sure of the most scientific way to share the benefit of having the bar end parallel (and end-link perpendicular to it), but maybe someone else can/will (Matt, you there?). I can just visualize it being more responsive in this orientation... I'm thinking of Archimedes and a lever, namely that between the car and the bar. Ha, just found this (good stuff on moment arm):

http://www.teamscr.com/sway.htm

So, there is some validity in the orientation of the sway bar ends. For those with lowered MINI's, and I know there are a lot, what have you done, if anything, to correct this? If you don't mind sharing a photo, that would be great. Thanks much!

 

im not sure about that one. ive used interium settings between the
holes on my previous car while using adjustable endlinks. that took
the swaybar end from this horizontal position you talked about.

it really made no difference that i could tell in terms of that being
a factor. obviously the swaybar setting itself made a difference.

perhaps Meb can explain from an engineering perspective if it
matters...but real world experience, i have not noticed any difference.

 

Thanks Ken for your input. I haven't seen Michael (meb) post in a little while, so he might be out for the Holidays... Yeah, maybe it's really nothing that noticable. I appreciate you sharing your experiences and thoughts...

 

Your swaybar isn't rigidly attached to the chassis, it rotates up and down in the poly blocks. Because of that, whether the arms are parallel to the ground or not isn't really a big deal. It doesn't change the action of the bars all that much to have the ends either up or down slightly. The swaybar works by being flexed when one wheel travels up (or down) relative to the other wheel that the swaybar is attached to. (Ok, it's not attached to the wheels, it's attached to the suspension arm, but you should get the picture either way)

It's the change in the relationship between the ends of the swaybar that make it work, not the alignment of the swaybar ends to the ground.

One of the reasons for using adjustable end links is to preload one side of the suspension or the other by adjusting the endlinks unevenly. That preloads the torsion on the swaybar, biasing the suspension on one side. It's a way of setting a different effective spring pressure on, for example, the driver's side of the car.

As long as the sway bar ends have enough room to move through their entire suspension arc without hitting anything, they're pretty much fine.

Others will disagree, as is their right.

 

From the pic, it doesn't look too bad. It's been a while since I set up my swaybar so I'm going off memory... If the car is lowered considerably, the angle between the bar and endlink should get larger. This will cause the end link to feel increased strain from the bar as well as cause some possible problems since the bar has more travel with the suspension.

An extreme senario of this situation was when my friend and I installed a swaybar in his mr2. The endlinks were set up fine w/o pre-load when the car was up in the air but we didn't think of what would happen once it was on the ground. We drove off and hit a bump and the car started creaking loudly over every little bump. We stopped and to our surprise, the bar was in the wrong position. Since the angle was so high between the bar and endlink, when we hit the bump, the movement of the shock inward caused the swaybar to shift from this type of angle: \_ to this: /¯ . By that time, it was dark out and working under the rear of the mid engined car with flashlights trying to detach the immensely pre-loaded endlink was not that fun .

Moral of the story: check pre-load with car on the ground and try to keep close to a 90 degree angle between the endlink and swaybar. As I said earlier, TonyB, yours looks alright. As long as you don't slam the car, stock endlinks should work fine.

 

If you go into the equations for the force on the sway bar, the angles you're talking about affect the lever arm. This will go as the sine of the angel from the horizontal, and is a second order effect for small angles. so what kenchan says makes sense. The largest factor will be the bar diameter (but remember, the formula quoted in the Saturn article is for solid bars, it's a bit different for tubular), then what hole you mount the end-link to, then this angle that you're looking at.

I think until one is at the sponsored race team level, this should best be set by looking at potential interference in at the limits of travel. Things may start to bump into each other, and that would be bad.

surprising that a saturn website would have such an excellent article on handling.

FWIW, my Mustang is runninng very soft spings (for a Mustang), pretty soft sway bars (I was leaning a lot at Sears Point), and it sticks sooooooooo much better than a Mustang with a stock suspension. That's because the Griggs set up does the correct camber changes with suspension compression to keep the contact patch parallel to the road even in the face of pretty severe (for track work) body roll. This means I can take advantage of the rubber, and still let the car respond to non-ideal road surface changes (read bumps) without coupling to other wheels. So the Mustang can really stick around bad turns. The Mini is getting to the point where the stiffer springs, and bars etc. are making it turn really well of flat stuff, but for crappy roads, I'm starting to skitter across the surface.....

Next set of books are going to be on suspension tuning. Now this will get expensive, and undoubtatly let me know I've spend on the wrong parts or in the wrong order.....

Damn!

Matt

 

Guys, most of what you says make sense to me. Heck, maybe it all makes sense... just fuzzy on some of the lingo... (only a minor in science here).

This tublular sway bar (H-Sport Comp) is a larger diameter than the other solid bars out there... but b/c it is hollow, it ends-up having the same effective diameter...

Matt, you're getting quite a library there! Spunky and kapps, thank you also for sharing your thoughts. I'm starting to realize that all is probably fine with my set-up, but I'm going to check a few more things, and then monitor from there... Thanks again.

 

I finally had some more time today to crawl under the car, under load (all 4 wheels on the ground). And, to my surprise, there is no way the rear sway bar ends can be at 3 o'clock or totally parallel to the ground.

In the photo above, the end shown is actually touching the top of the wheel hub! So, about 2 o'clock (a bit past) is the max until there's an udesirable positive stop...

I removed the bottom bolt of each end link, and I want to share that this is very doable with the wheels on, esp with my open Volks. I used a ratchet with about a 10" extension, and a universal at the end to get a stratight-on approach and square fit on the nut. A larger rotor would be more problematic. A wrench is needed on the inside to keep it from spinning though. With long enough arms, you'll find yourself hugging your tires to get this done . If you're creative, you can wedge the wrench in such a way so that it would positively stop on something solid (not a brake line, unless you want a break line ), so such reaching won't be necessay. For these Alta end-links, we're talking 14mm for the mounting nuts, and also for the jam/adjusting nuts. The back nut is not 14mm though. Oddly enough, I didn't find a metric that worked, but a 1/2" fit perfectly...

Ok, question time:

Once the sway was not achored via the end-links (free to move), I rotated it up and down, and it moved well. However, I noticed that when I got that one end touching the hub top again, the other end was like over an inch higher. The ground was relatively flat... This strikes me as very odd. The bar, brand new, was perfelcty flat on floor (lied in the same plane).

1. Is this something to be concerned about?

2. Has the bar gone through some torsional twisting that has caused it to be deformed, and hampering its integrity?

3. If so, what would cause this? What first comes-to-mind is lowering it, and keeping the stock end-links...

4. If everything is snugged-up with the nearest bar end like .5" away from the top of the hub, can I expect that all motion under driving conditions to be only upward, or at least mostly? No pre-load here...

5. As a follow-up, if there will be downward motion from this point, how high above the top of the hub should the sway bar end be such that it will not impact the hub under driving conditions?

6. What exactly is pre-load defined? I can turn the ajustable end-link such that it pulls the bar down, or the opposite, pushes it upward. Are both pre-load? From everything I've read, I don't want to pre-load... I can spin the end-link with my fingers freely about a quarter turn, and this is the range where it exhibits no load characteristics. After that, it gets more resistance (harder to turn), and increased load (push up, or pulling down of sway bar end). It almost seems that an ever so slight about of pre-load might be desired to keep things from rattling. I know some have complained about noises from end-links...

I really appreciate any input you all can give on the above. Thanks much!

 

tony, tony... just enjoy your swaybar.

 

Ken, I've been enjoying a rear sway bar for 2+ years... Something tells me that if one end is sitting on the hub, impeding motion, there's something not set right, and/or damaged...

 

Did you put your 140 lbs in the driver seat when you did this? That will make a difference.... What about gas?


You can always take it off to measure it again.

I'd guess that first, the area you're testing on isn't as flat as you think, and second, if you didn't weight the car the same as when alligned.


IT will go both directions. When you laod one side of the car, you can unload the other. Also, cresting hills and turns etc can cause one end or side to unload.
No clue. The best way to test this is with the top of the strut disconnected, and move the arm through it's full range of motion to look.

Pre load is when the bar is twisted in the "at rest" positon. One of the reasons it's bad for street cars is that they turn both direction, and one lead direction will have a force that starts at the pre-load amount and increases, the other will first go to zero and then start loading again. Now, if you're a circle track racer, or a redneck turning left (re: Nascar), you may want thins. Street driving, bad.....

Hope this helps,

Matt

 

1. Doesn't seem right to me - but is it the bar, or the suspension?
2. Check the height of either side of the car to see if that is a factor - I've measured significant height changes in springs. You've got coilovers, right? If you corner weighted, that could alter the relative heights.
3. Can't see why the end links would cause deformation - hitting the hub, maybe, but hey, it's a spring - it's supposed to flex.
4-6. What Matt said.

 

sorry, i just got too lazy to read your huge post.

i went back and read the part about the unevenness of your swaybar.

it sounds like your swaybar is bent. which is nothing unusual..ive had
swaybars bend out of shape a few times on other cars. just needs to
be replaced or compensated using adjustable endlinks. bascially
fatigued.

 

Matt & Eric, thanks for chiming-in...

I did recently have the car corner-balanced, and maybe that's it. But, if the rear sway bar is not connected via the end-links, do the coil-over perch settings matter or influence where the free bar ends set in relation to the hubs? Without the end-link connections, the bar is just lying there in the bushings, flat (unless it's bent). And the hubs (their up/down positioning in relation to the bar) should not be impacted by coil-over tuning. Gosh, I hope I'm not missing something here...

Matt, no, I wasn't in the car (thanks for reminding though as I'll need to do so before I snug things-up, once I sort this all out). But again, if the links are not connected, the springs or coilovers should be a non-factor in how the free-spinning rear sway bar sets in relation to the hubs. Once the links are connected, I can certainly see how my weight, gas, etc are a factor. If I'm wrong here, please don't hold any punches back guys .

So, as Matt said, maybe it's the ground not being as flat as I think. Well, I do live in a canyon, and while I have 1.25 acres, virtually none of is really that flat. But, I don't think that I'm too far off though... at least not so much as to see well over an inch difference in how these bar ends sit...

It almost sounds like I might have screwed-up my corner-balance by doing this as I certainly had load on the stock end-links. I asked the shop if I should put the adjustable end-links on before their work, and they said that it wouldn't matter. I'm not so certain now...

I appreciate the enlightenment!

Edit/Add - Ken, just saw your post. No need to aplogize at all. I might try taking the bar out next weekend. I will try everything else first though...

 

The bar ends should be paralell Tony.

When the car leans, the sway bar twists - one side up and the other side down. If the bar ends are pointed down, there is an advantage to the side the twists down. If the bar ends are pointed up, there is an advantage to the side that twists up.

I'm checking in real quick. I'll write in depth in a day or two.

 

Michael, thanks for checking-in, while probably on the road...

Sounds like I'm getting some confirmation that I might have a deformed rear sway bar...

And I was just thinking that I don't need to take the bar out to verify this. I'll simply get the rear on jack stands, and remove the wheels. It should be easy by looking through wheel well to wheel well (line of sight) to see how things line up. I'll even have a level and straight edge of some type...

Would suck if the bar is bent though . Michael, thanks again!

 

You use the sine (a+b) formula. For very small deflections from a "non-parallel" geometry, the effects cancel, they are second order or smaller). For larger deltas (think the bar starting at one angle, and as the car leans one angle getting larger and the other smaller), it's not a true cancle, but the effect is pretty small none the less.

But parallel to the ground isn't the right "ideal". the correct ideal is perpendiculare to the suspension direction of motion. The lower arm defines this arc.

Matt

 

Matt, that does make sense. I'm pushing my limits as to what I can comprehend on this topic via these means (the typed word)...

If I understand correctly, you mean the end-link being _I_ to the trailing arm's motion...

At this point, even if parallel to the ground were the ideal, it ain't gonna happen on our MINI anyways, as I shared (impact into hub top)...

Another thought just occurred to me... the bar mounts to the subframe in such a way that it can be slid forward/backward for location purposes. I wonder if one of the ends has moved on me? A possibility that I can easily check...

Matt, thanks for the math!

 

Matt, Tony,

A face to face conversation will bring this to rest quite easily...perhaps a pencil and paper too.

The ideal is a moving target in many ways. Matt is correct in sighting the relationship with the control arms. Another ideal is the amount of space available during a complete suspension stroke; if the end links are made as long as possible, the sway bar lever arm is in effect longer and the sway bar has more leverage. If these end links are installed as short as possible, the lever arm is reduced and so is the effectiveness of the sway bar. Space will limit the length of the the end links, and as well, the asymetric twisting - which may not be noticable at small deviations from the ideal...but may be significant at larger deviations - as Matt suggested.

We all write about what sway bar sizes are correct, but there are many little things about sway bar design that can make two 22mm bars vary; lever arm length is one, and, where the bar attaches.

My 99 Si's stock rear bar end links mounted to the lower control arms - 2/3rds from center. Ground Control's 22mm bar end links mount to the bolts that connected the dampers to the lower control arm, 5"-6" farther out from center. So, not only is the bar thicker, its mechanical advantage is way better becasue the lever arm is much longer. The Ground Control bar would still be much stiffer than a stock orientated 22mm bar. Stock is 16mm or 17mm...can't remember.

The Ground Control bar is, however, a beast - very heavy! A solid steel adjustable bar - no holes.

This whole suspension tuning thing is an iterative process, it's definately not black and white. Many things depend upon other assumptions and goals. I continue to write mostly in a black box because I do not know anything about what others have done or what their goals are. Hopefully some of this stuff helps out. Tonight I'll open a Super Tuscan and go look at the whole mess...you know, sort out the suspension universe...maybe blurry eyes and a foggy brain will help...

 

Michael, very interesting! So, the longer the end-link, the better... as the sway bar will have more leverage, as you say. And, as the end-links in the rear become longer, the sway bar ends rise... contrary to my original belief that the ends would best be served near horizontal (parallel to the road) as possible. This has become very educational...

Well, I was able to make some progress today, and I have some good news. My rear sway bar is not bent! First, here's a photo of my MCS up on 4 wheel ramps. It is in a fairly flat area...



Then up on jack stands in the rear, with the wheels off, the suspension can hang. With the bottom of each end-link disco'd, I rotated the bar downward until it hit the hub top on the passenger side:



I then went over to the driver side and saw that it was up a bit higher:



I began to check-out to see if the bar had been stressed or torsionally twisted, and saw no signs of such. I looked through the wheel wells and the bar ends looked to be very much in-line with each other . I lifted and dropped the whole wheel hub assemblies to make sure that they were hanging down fully, and they were. But, one of the sides was hanging down further than the other (closer to the ground), just a little, but probably enough to account for the difference that I was noticing with the sway bar ends in relation to the hub tops. Just more confirmation that the bar is not bent. Why one of the hubs hangs a bit more, I don't know. Maybe due to the control arm adjustments, or just the way she came off the line...

And as I mentioned earlier, the sway bar mounts to the sub-frame on slotted bushing brackets. I loosened those (13mm), and slid them forward, and tightened them up. This actually seemed to help the positioning of the bar...

The 16mm bolts that anchor the sub-frame were tight, and not an issue...

I put the wheels back on, lowered it back down onto the wheel ramps and got my wife to sit in the driver's seat, along with her purse, and an SLA battery (13.5 lbs) - about 140 lbs. About 5 minutes later all was tight, and the rear end-links were done.

I'm not lowering it back down just yet, as I still need to do the front end-links. When I remove the front stock links, will that change what I've done in the rear, as far as no pre-load? Something tells me that I'm going to need to play with all four simulataneously...

 

Tony,

I suggest, for goofs and giggles, you try a short and a long setting for the ends links. Take the car out for a very spirited ride where you can really load up the suspension, but not achieve high speeds in case something doesn't work out. Try this with each setting to get a feel for the difference. But you must load up the suspension to near track level loads. Typically nasty traits show up only when the suspension is really stressed.

The only limit to the adjustments, as I wrote previously, will be the amount of space available as the suspension droops and compresses...sometimes it is beneficial to actuate the suspension arms without spring/damper installed. Unfortunately, the sway bar makes moving the suspension arms by hand nearly impossible...a jack???

There are two formulas for figuring out the % bar stiffness. These are usefull if only to compare with stock bars. Thickness is easy; multiply one bar thickness to the fourth power and do the same with the stock bar. Divide the larger by the smaller to get an idea for the % increase. I did this calculation incorrectly in another thread - I squared the numbers.
Calulating the lever arm is more difficult...I have the formula somehwere. If you like I'll dig it up. It's only worth a look if the bar ends are located in a different place or if the end links are longer.

...remembered something. Keeping the bar ends parallel typically does a few good things; no contact with other components (this assumes the stock bar was parallel) and allows fairly optimal leverage without going over board. This last thought is a very important one. Sway bars do not twist with a linear force. They do so with exponential force. So, my suggestion above regarding really loading up the suspension is vital. The bar should help rotate your car without reaching a point where its leverage suddenly snaps the car around. You may find cornering on three wheels is okay for an auotX event, but not a fast sweeper on a track.

If you find that nearly perfect balance with your bar set-up Tony, but it still feels a tad twitchy, use rubber bushings instead of poly. The rubber will remove some of the edgyness.

Keep in mind that bar diameter and length are typically changed like underwear on a racing circuit to suit each track's demands. We, on the other hand, are trying to set-up for the best of many worlds...a far greater compromise.

hope this helps Tony.

Michael

 

Michael, as I shared in your PM reply moments ago, thank you!

The roads are currently wet, and will be well into the New Year, so I'll have to hold-off on experimentation. These tight canyon roads allow for good loading, w/o much speed though, so I'm fortunate...

You know, I'm not sure if the stock bar is/was parallel. And from my experience now, parallel is not possible, nor desirable on our MINI. The range from positive stop to positive stop is like a little after 12 to a bit past 2. The mid-point might be best to avoid contact, so not near parallel. I would love to put a video camera back there to see what's really going-on!!!

Hmmm... that has me thinking. Maybe I'll visit the Camera/Video forum to see if anyone has done this... Thanks again.

 

It's always a good idea to baseline stock conditions and impressions.

The stock rear bar orientation is slightly up towards the endlinks. If you were to draw a horizontal line thru the center of the bar where it attaches to the body and call this intersection nine O:clock, the bar ends are probably at two O:clock - three O:clock being horizontal. There is not a lot of room back there for much fiddling.

 

Let's see if getting some video would be helpful:

https://www.northamericanmotoring.co...961#post762961

 

This is a really old thread but the info here is all over the place and people doing research (like myself) may get confused. I think I can help on this subject on purely an engineering level because I are one! The answer is really very simple too. The most effective position of your swaybar is determined by the orientation of the endlink and the swaybar leg viewed from the side. 90 degrees is the most efficient orientation (with the car loaded of course). It has nothing to do with the orientation of the road and the bar. You can test this theory out using a socket wrench in your hand to break loose a bolt. 90 degrees give you the most torque on the bolt.

If the bar has interference (hits the hub) in this position, either your bar is on upside down or it is bent (or it is not the right bar for your car). No way would it be impossible to install the bar in it's most efficient position.