mike opalisky

i know they tweeked it in 2007 .. what year was the next change

Rudeney

i understand there were a few more teaks and part revisions in MY2009. Aren't they still using ABC on the R231?

BlownV8

The newest and lowest mileage one you can find. The issues are related to age, mileage, and heat. There is no magic pill with ABC. It's going to break at some point and it will be expensive to repair.

carguyshu

the tweaks are made continuously to all parts of the car, not just the ABC over time (things like an update to a particular hose for instance) the R231 has ABC as an 'upgrade' option on some models now.

funymuny

I think of the ABC system as any other hydraulic system that is used in aircraft (commercial jets to smaller private aircraft), construction equipment, industrial settings, etc. They are a wear item. MB started off in my 2003 by not even acknowledging the 'wear' component (and as stated above, wear is a combination of use, heat, age). It's part of this car. I accept that ABC needs some preventive maintenance. Keep the fluid and filter clean and new. Cycle the ride height periodically. Keep the seals opening and closing. That doesn't mean a hose won't blow or a pump won't go out. I went through the seven stages of grief on my first one and concluded with what I wrote above. So I bought a newer one but have no intention of getting rid of it anytime soon. I changed the ABC fluid and filter within a few weeks of getting it. It was four years old with 23,000 miles on it. Enjoy...Mark

Rudeney

For all the ABC woes on the forum, no one seems to mention the good things about it. I find the system to be very effective. In sport mode, I get flat cornering and quick handling response. With sport mode off, I get a very comfortable ride. I use the height adjustment daily, raising the body to make getting in and out (mostly out) easier. It's the best of both worlds in terms of decent handling and MBZ comfortable touring.

carguyshu

ABC when working properly is certainly superior to a conventional passive suspension as it can give a great balance between ride and handling that a conventional system just can't. That being said it can also be a pain in the *** and in my opinion is a far inferior active suspension compared to magneride. Magneride not only works faster/better, but it also has the same reliability as any other conventional passive suspension. Now that GM no longer has exclusive rights to it I wish MB would swallow their pride and use it instead of ABC.

funymuny

I absolutely agree ABC is an incredible suspension system. Maybe there are superior active suspension systems, depending on how 'superior' is defined. But hey, it's part of the price tag. Mark

carguyshu

There are basically 3 active suspension systems out (I don't count airmatic or any air suspension active as it cannot react quickly enough. It just offers different settings)

1) ABC- uses hydraulic fluid and either fills or empties each shock as conditions warrant continuously. When you are taking a sharp left turn, for instance, it will send fluid to the right hand side shocks to decrease body lean. Because you are dealing with solenoids that must open/close to let fluid in/out it cannot react as quickly as other systems. In fact, it only operates at 5hz (the slowest of the 3 systems) which equates to 10 times a second.

2) CVRSS (continuously variable road sensing suspension)- this is at least what Cadillac called this system when they used it in the late 90s and early 2000s (they do not use the system anymore, but several manufacturers still use a similar system today). This system uses regular shocks/springs, but the shocks have a valve inside that can open and close to adjust the dampening rate on a continuous basis. Think of it as having a robot hand at each one of your shocks adjusting the dampening rate spinner found on adjustable shocks. These shocks are expensive to replace and because a valve is still opening/closing can only react so fast to changing conditions. The valve will also wear out over time and need replaced. These systems generally operate at 1,000 time a second, which is much faster than ABC.

3) Magneride- Originally created by Delphi and exclusively licensed to GM was first found on Cadillacs and some corvettes. Ferrari also licensed the tech out from GM in the early days. Since GM has sold their rights to it you are now seeing it in Mustangs and other cars. With this system you have a conventional spring with a shock that instead of being filled with shock fluid is filled with a special fluid that has iron particles floating in it. When an electric current is applied it can either instantaneously stiffen or soften the ride by changing the viscosity of the fluid. The current generation of Magneride can react at 10,000 times per second (far faster than any other system by a large multiple time margin). The nice thing about these shocks is that there are no parts to wear out and because of this the shocks last longer than any conventional shock. The only way they can go bad is if the fluid starts leaking out of the shock. That is it. They are also less than half the price of either CVRSS or ABC shocks to replace as well (but still more than a conventional shock).

bobterry99

Only ABC is truly active. The other two systems you mention and dozen others are considered semi-active.

Rudeney

Yep - those other systems just adjust the firmness/response speed of the shock. ABC can actually change the travel length. So taking a tight curve, it can lengthen the outside shocks and shorten the inside shocks to keep the body level relative to the road, thus "leaning into the curve" like a motorcycle. I know it's somewhat artificial, but it sure make curves feel more exciting.

carguyshu

I suppose 'adaptive' suspension would be a more accurate term. If we are getting super technical here Lotus is actually the only fully active suspension system as ABC only can vary spring rate, but not dampening so it cannot be classified as a 'truly active' suspenion. I am unaware of any other system besides hydraulics, solenoid/valve, and magnetorheological (the 3 I mentioned). If you could please enlighten me to these dozen other systems that'd be great.

bobterry99

What defines and distinguishes an active system from a passive one is its ability to input energy into the system and control body movements through the application of force -- it has nothing to do with spring rates or dampening. Plainly ABC is an active system.

Mercedes offered ADS I and ADS II. For other manufacturers see https://en.wikipedia.org/wiki/Active_suspension.

BlownV8

I believe in 2013 they finally started to offer ABC as an option on the SL550. Honestly, if you want to own an SL longterm without too many worries that would be a good option. Oh yeah, almost forgot about the SL350. No ABC there but I'm not sure if they imported to the us.

carguyshu

The wiki you linked only lists the 3 suspension types I mentioned plus electromagnetic recuperative, which is something that has never been used.

this technical school doc further explains ABC compared to other hydraulic systems and how it is merely an active roll control device and not a true active suspension as it does not have a double acting hydraulic actuator. Further, it specifically states that the Lotus system is the only truly active suspension and that it has never made its way into a production car.

http://www.autozine.org/technical_sc...uspension3.htm

Again, this is all if we are being super technical here on verbage. What I called 'active' before really should have been called 'adaptive' & production car wise there are only the 3 types I mentioned previously.

rorywquin

In addition to the other features, ABC now has cameras that scan the road ahead and adjust for the varying surfaces -

bobterry99

It's clear to me now that you misunderstood my first post. Here is what I wrote: "The other two systems you mention and dozen others are considered semi-active." Those words merely state that there are many semi-active suspension systems -- nothing with regard to operating principle or anything more is implied. These are some of the semi-active systems listed in the Wikipedia article: Toyota TEMS, Mitsubishi Dynamic ECS, Mercedes ADS, Land Rover ACE, Peugot AMVAR, Audi DRC, BMW ARS and EDC, Ford CDC, and Volkswagen DCC.

I think most SL owners know this statement is false and that ABC is more sophisticated than the statement implies. ABC is an active system capable of controlling dive and squat as well as roll, and of course it controls the level and height of the vehicle.

Using this criteria one would conclude that Bose's experimental suspension is not a "true active" system, and that would be patently ridiculous. The Bose system uses motors and no hydraulics at all.

The idea you may have intended to convey is that ABC is not a fully active system, since it employs conventional shocks and springs in addition to its active components. In technical terms ABC is described as "low-bandwidth active suspension."

carguyshu

agree on the fully active system. those other systems listed use either adjustable valves or an airshock, which cannot really do anything that actively. You can switch the settings on air shocks (like airmatic) but it can't switch settings fast enough to automatically adjust to ongoing road conditions

alk247

I have both - MagneRide and ABC. While Magnetic is absolutely wonderful system with extremely fast reaction time and no mechanical (moving) components, it can not by itself change the ride height. It uses air bags to do it, so ride height is controlled almost in a static mode. ABC can do it dynamically, so it is a truly active suspension. Unlike MagneRide. And magnetic shocks do not last as long as conventional ones. Iron particles seem to be to some degree abrasive, so they ruin seals on the shocks a bit faster than normal fluid. And they cost about the same as ABC shocks ($1,000 e.a. if you go through the dealer).

next2pool

I had the pleasure of working with the Corvette team in the early 90's on a fully active system that was 100% hydraulic with no springs. When it worked, you could travel through dips and potholes with a totally level body motion--it was like something I have never experienced since. However, the hydraulic flow requirements were tremendous with an amazing tangle of large diameter plumbing from front to rear. Additionally it was a huge challenge to cool the fluid. In the end, the system was cancelled just before start of production. When I retired, one pre-production vehicle was squirreled away while the other were scrapped. I wonder if it still exists.