Mercedarios..!
I have read several posts where anti-sway bars are installed after coil-over conversion. I did the coil over conversion and no anti-sway bar yet.....but I have noticed that the vehicle has very little tilt on the turns....I am sure it is due to the low center of gravity and plus the short travel of the struts. My struts are Bilstein and they have a 3.5" travel, which means 7" height change at the wheel. So in the worst case you will have 7" lift differential which translates to an angle of incline to be around 5-1/2 degrees...not too bad..! Now, unless you are a racer and want to take fast turns, I kind of agree you spend the $$$ for anti-sway bars....otherwise don't worry about these 6 degrees of tilt...! Would like to hear any insides on the subject..!

 

I suppose if you are going to drive the car aggressively, they would help, but for normal driving with the coilovers I have, hard to tell the difference between ABC and coilovers no bars.

Your setup may be different, because it utilizes factory struts and springs, you may not have as much spring rate as the aftermarket coilover.

 

From what I've read on various groups, those that don't fit bars seem happy with the way the cars drive. The horror stories seem to come from prophets of doom who have not driven an SL on coils at all. I fitted SL 350 bars on my 500, I never tried it without..The thicker aftermarket bars available would have cost treble, I doubt they would warrant the expense.. The car drives through bends flat, like it's on rails. I'm far more confident in it than I ever was with ABC. My son also says its better and I trust him completely.
So in answer to your question I'd say no the sway bars are not essential. Also those that say that 350 bars don't fit under any V8, I can assure you they are wrong, they do fit on the SL500 without spacers or mods.

 

I've converted my SL600 to coilovers using the kit from VVK. Haven't installed the swaybars yet, but once I've got the time to spare on it, I will.

The car does drive and turn well without the sway bars, not any terribly noticable body roll.

But yesterday I ran into the exact situation that proved to me the value of installing the sway bars. I was on a long, curving freeway ramp that turns out to have a pretty big dip near the end of the curve where the roadway also levels out. And yes, I may have been exceeding the speed limit just a bit ..........So, the right side suspension is already loaded pretty hard, then I hit this dip. Felt a pretty hard bump from the right rear and the car was a bit unsettled for just a fraction of a second, but was never any where near danger. Took a quick look at the car on arrival at my destination and could see where the right rear tire had contacted the plastic fender liner. No contact in the front.

So the lesson is when you get a car in a long curve with bumps in it, that is when you'll really see where swaybars are good to have. But I can also see where if you don't ever drive aggressively you could get by without them.

The other lesson is that public roadways are not built to racetrack standards . That long, sweeping ramp may look like it'd be fun to hit with some speed, but try to resist the urge if you're not very familiar with the road 'cause it could be hiding a pretty big surprise for you.

It'll be some months before I install my sway bars. In the meantime, I'll still be having fun with my car, just taking it a bit easier on those long sweepers.

 

My 2004 Sl came with Strutmasters. It handled fine. However during Covid last year there was a great deal from Cardid for the rmt bars. I bought the front bar. Had it installed (not easy). The car now drives a bit more flat. But I have never encountered an experience to compare as Bruce describes. As for the prophets of doom I will agree that a front suspension without a sway bar is cause for concern is a bit odd to. I cannot see any need for the rear bar at all. It is my opinion after 2 years reading this forum, many of those fanatics of the ABC Club also belong to the Prophet of Doom club too.

 

I am curious: Can someone explain what he think what sway bars do and how they work?

 

A sway bar connects the left and right suspension, making them interdependent, to a degree. I my native language they're called torsion- or stability bars; all terms reflect their functionality. When one wheel 'wants' to jolt up (or down), it is confined by the other, which absorbs part of the vertical force by mimicking the same jolt to a calculated extend. The same goes for 'roll' during a turn; as the outer strut wants to compress, it is limited in doing so by the strut that seeks to extend, they even out to a degree. Hence the inner wheel keeps more grip.
My two layman's cents about the consequences of eliminating sway bars from a good design:
1- the more the struts are allowed to fully respond to changing load, the more steering behavior will be effected. A more flexible or absent front torsion bar will induce more oversteer. For the rear bar: more understeer.
2- installing one bar and omitting the other would introduce uneven stress in the car's body. Your driving attitude, the road and the over dimensioning in the design would decide whether you are causing friction (movement) between parts that were designed to stay put (think of anti corrosion coating failure, fatigue).
Anyhow, the rigidity of a design is working all the time, not just in extreme situations.
3- a dramatic result of altering a car's OEM set up like this, probably occurs during an unexpected incident/manouvre. ESP was endlessly tuned to the original set up, maybe it will respond adequately to non spec behaviour of the car, but I wouldn't bet my wife on it. Likewise, driving on under pressure tires or with only one brake working (I did that in a W113 I had just bought, with three seized claws...) is not too much of a problem, as long as traffic rolls as expected. I was aware, over-over cautious and had no trouble. But in a sudden situation demanding more of the rig's capabilities things could have turned out very nasty. Our R230's are heavy and powerful cars, so stay safe and think twice about any structural change.

Okay, shoot me - I'm sure I am missing a point or two. There's more experienced folks around here and we all like to learn!

 

With a stabilizer, the outer wheel is more and the inner wheel less supported in a curve to the same extent. If the stabilizer is missing, the outer wheel sinks more and the inner wheel sinks less, the angle of inclination doubles and the result is oversteer.

Then, for me, the distance between inner wheel to outer wheel is about 180 cm at a max difference in high at about 18 cm: 10% = 5,7° angle of incline and time to worry, for me.

 

The stiffer the spring rate is , the less the sway bar works. The sway bar increases spring rate in cornering applications by weight transfer.

Softer springs without anti sway bars will roll more than a car with stiffer or more spring rate. Roll center will affect this as well. Maybe my coilovers have stiffer rates than others have, and I have the car lowered 1” or so.

I don’t consider the r230 a handling machine, nor powerful in the early 500 versions. I was happy with the coilover sans bars, but like I said they don’t hurt .

 

Even if the slope is relatively small, the fact remains that there are absolutely no reserves left in such curves. At least as important as the fact that the spring rate of the wheel on the outside of the curve is increased is the fact that the stabilizer reduces the spring rate of the wheel on the inside of the curve at the same time. So maybe it is safe as long as you driving Miss Daisy. In a SL. With more than 500 HP.

 

Which is more dangerous, blowing a hydraulic line in the middle of a hard corner, or no sway bar, or driving Miss Daisy and blowing a hydraulic line.
Probably a bigger deal if you haven’t actually driven one with coilovers and no sway bar, which I would guess you haven’t.

I’m not saying it isn’t going to improve the handling, but the body roll is minimal without them. Again this is my car, other cars with other coilovers may differ.

 

For information
https://low-offset.com/workshop/sway-bars-explained/

http://speed.academy/how-swaybars-work/
Hope it helps

 

How high is the probability that a hydraulic line blows, compared to a critical situation on every journey? My son drives an SL320 without ABC, so I know at least the handling of a standard chassis with sway bar. On the handling course, that's the difference between driving like on rails and Miss Daisy crying for help. But you are right, i haven’t driven a car with standard suspension but no sway bars.

If a car without sway bar is working with stiff suspension, how about driving comfort then? I had to drive an older SL with Bilstein B6 instead of comfy B4, that was a torture, for me.

 

Are you saying that an SL with ABC is like driving on rails, and and SL320 without ABC is like "Miss Daisy crying for help" ? That the non-ABC car is that much worse?

 

What I find most interesting, as far as I know has not been discussed is the subject of coil overs and sway bars. Frederick is stating front and rear bars must be used together. Using just is front sway bar is a problem for the car.

 

I can’t speak about standard suspension and no sway bars, but can with coilover lowered 1” and no sway bars. It’s very compliant and reassuring to drive. I’ll let you know when I rip the
ABC off of my sl55 and replace it with coilovers how that works without sways.

If the ABC system wasn’t such a bad design and problem, there wouldn’t be coilover conversions and discussions about this, and I we wouldn’t be talking about this. There’s a reason why these cars are depreciation monsters.

 

I just wish we could once have a discussion about Coil Overs and Sway Bars which did not deal with ABC. We all know how we are looked upon, here in this forum by the ABC addicts. What are the odds? You are traveling down the Highway at 140 mph in your "nor powerful in the early 500 versions" and you are about to have a hydraulic hose rupture. BOOM! At that moment would you rather have coil overs? So does Safety trump a less safe system? and does German Engendering consider safety first? As for me I would rather have a coil in place instead of a rubber.

 

With the suspension side of things and Mercedes, engineering flaws seem to be designed in. The w211 e55 I have will drop in the frame when the suspension fails, r230 undriveable when it drops. I owned a Lincoln mark 7 LSC and when the air suspension failed the car could still be driven safely to a repair site. Mercedes seemingly won’t do that, and usually getting the car in the rollback causes body damage
increasing the cost and aggravation.
All of the Mercedes I have owner with hydraulic suspension from 126 to r129 to the 230 have had issues with lower mileage. I’m not a great fan of air suspension either, but it’s less problematic for me.

My sl55 has 43,000 miles on it and I have flushed the fluid twice, The car will drop corners sometimes in less than 30 minutes, and when in park and running it slowly raises up to full extend on all four corners. It’s really disappointing and unnecessary, but realistically why these cars are not worth much.

Coilovers may not be for everyone, but maintaining a flawed design when there is a simpler solution isn’t for me. No more chf11s flushes at $20 quart and concerning myself with expensive parts replacements.

It should be noted that my cars are lowered so the ABC ride is diminished from stock height. The coilover aren’t much of a comfort change. Cars with stock ride height may have different results.

 

I wrote "On the handling course". These cars in good condition are valued in Europe. If something breaks on it, it will be fixed, sometimes even before it breaks: The German way. I suspect the misunderstanding will be assuming that you can drive a $ 100,000 car without corresponding high maintenance costs. Still, I find the theory about the standard chassis interesting.

 

The German Way ? interesting. yes these cars in the USA are not valued I should have thought so assuming the misunderstanding that ABC is a crap system. What was it about that Black Series.....

 

We'll, the fact that for decades many Merc's were reimported to W Europe from the States supports Andreas' view. Buy cheap, restore authenticity and enjoy owning a classic Merc. Up to now classics from the brand have never been a bad investment. I sold a Merc I bought in 1998 in 2020 at more than thrice the price. And it didn't come real cheap, imported from Switzerland.

 

I was hoping you would discuss the threat to body integrity not using a rear sway bar.

 

I am just dumfounded/stunned about the discussion in so many levels regardless if it an MB vehicle or not.

Any vehicle to be driven in a non-straight line above Miss Daisy's speed requires an stabilizing system of some kind. Either electronic or mechanical a system is required. Sway bars are just a means to a purpose, i.e. stability. If there is a mechanism to inform one side what the other is doing and actively react to it in accordance with the dynamics of the vehicle, including damping/braking systems, the vehicle should be safe to drive. Attempting to do so w/o OEM specifications, it is a major undertaking, and w/o the deep pockets of the manufacturing for all around testing, a half baked project.

​​​​​​ If during the conversion from ABC to whatever system is chosen, the communication path from left <-> right is broken, it MUST be restored somehow, electronic with sensors, neumatic or else, i.e sway bars.

Attempting to ignore a stabilizing system, to save some money, it is just looking for trouble. It is no my vehicle, so do as you please but consider there are other on the highway as well

My 2c

 

Seems like 4 people with coilover conversions and no sway bars have stated their car doesn’t exhibit dangerous behavior, but the people who have only driven with ABC suspension say that the coilover without sway bars is dangerous.

 

Well all of that is peachy keen. All I want to know Fredrick is you made the claim that not using a rear sway bar with the front sway bar was going to damage the chassis and body??????
i couldn't care less about these elites who shove it down our mouths about the Coilovers every chance they get. Read above just once.........can we have a discussion about sway bars and not hear from the porcupines that is the American Way

Step up Fredrick......you made the claim. you start a very interesting subject which I think is full of hot air...

How about hollow bars instead of solid bars lowering unsprung weight?

discussion ???