Top 3-5 cost efficient ways to decrease body roll?
 

1. $
2. $
3. $
4. $
5. $

Stiffer coil springs/lowering springs
Stiffer anti roll bar(s)
Polyurethane suspension bushings
Lower profile tires
Less weight/lower center of gravity
drive your mercedes slower, it is a mercedes :D

which bushing will decrease the roll the most?

So the #1 improvement will be from new stiffer springs.

Anti-roll bars will decrease the body roll the most, Stiffer/shorter side wall tires will decrease the sensation of body roll allot, if you do bushings you normally do them all, Stiffer springs will not reduce roll only slow it unless they are lowering springs then they would drop your center of gravity.

um... why do you wonder? specific reason? or are you just curious?

my 300cd coupe with only 14k miles rolls on sharp turns. I will go to lower springs and new lower profile tires and wonder if that alone will be enough.


not sure what bushings to change. All of them doesnt clear up what bushings to change will decrease roll.

sway bar bushings, sway bar end link bushings, shock bushings, and control arm bushings are all options. Im not sure what options are available for mercedes but if you can get them it is rather labor intensive and unless one of the originals has failed will probably be the smallest gain.

Is it like this? ranking on 20 star system.

20 points new sway bars $500-1000

9 points lowering car because this lowers center of gravity not because springs will stop the roll. stiffer will only slow the roll.

6 points. lower profile tires because lower center of gravity and less give to tires.

2 points new shock absorbers will only slow roll. 2 new bilstein Hds 140 each plus installation and new bushings. $400 dollars.
new shock absorber bushing will have ? effect but this is easy to get at so cheap to do or are the shock absorber bushing cheap also.

1 point. new bushings only if broken expensive change for control arm bushings.
sway bar bushings only if change sway bar.


I have 30 year old bilstein comforts (stock i believe) and i was going to change to bilstein Hd to decrease the roll and handling. But it might be better to keep them and spend the money on sway bars.
i think my shocks dont bounce when i push on a corner.
somehow i think i will get more than 2 points return on my ride if i change the front comforts to hds. Is 6 points for new hds in front more accurate???

Thank you.

on your car here is the order I would follow. and judge the performance changes before moving to the next step.
1. inspect or have a handling oriented shop inspect all your rubber body mounts and bushings. replace anything that is worn/aged. some pull all the rubber, and replace with urethane, or aluminum.
2. replace the shocks with HD's
3. change to larger wheels with lower profile tires. 17" wheels with 35 ar tires would do nicely.
4. replace both front and rear swaybars. you may have to go aftermarket or actually have one built to get the roll under control if the above was not sufficient...
5. install control arm travel limiters... not for the street...

that I wonder.

If my bilsteins comforts are low mileage and the car doesnt bounce more than once.

then shouldnt i skip buying shocks and go right to the biggest roll help which is thicker sway bars.

if your were only to do one sways or HDs in front, at least for now, which one would you do.

nope. I'd do it in the order I listed. each will incrementally improve the body roll. sway bar is a large expense. rubber mounts, and shocks will make a big improvement. tires will make a big improvement in feel of the road.
for which end to work most... you'd have to consult a road racer... too stiff a rear bar can affect handling badly... it's gotta be balanced, although I think the stock 123 bar is pretty wimpy in the rear...

w123 wagon sway bars are thicker by 2mm vs the sedan/coupe sway bars- that will help. Replacing the whole front sway bar is close to a 20 hour job. :eek: Vogtland springs were the stuff to buy a bit back- they lower and are stiffer. I still have the rear set in my garage because I have only wagons- and wagons rear end has the SLS- which I do not want to mess with.

I have heard that a w126 rear bar will help alot.

... I'd not think a 126 bar would fit... the axles are 1.5" wider each... that's 3" more between the rotors...
does anybody know if they will fit?
I have heard the TD/Wagon rear bars are 15mm instead of the sedan's 13mm

since it takes 20 hrs to change the front swaybar, it would be a very costly change if add up labor and cost front sway bar.

Changing the rears to 15 mm is okay to do if you leave the fronts in?

Changing the rears will decrease the front roll also.

No way is it a 20hr job. It is a 2 man job tho!.

I disagree with everyone else this is my order.
1. Sway bars/bushings. TD sway bar in front as mentioned, the 15mm HD rear is NLA afaik, but there is a guy who made his own by cutting and welding. You can have them custom made for ~300. The 126 bar is 2cm to wide but comes in a 19mm variety.
2. Springs, there is a pair of vogtlands for sale now, otherwise you can purchase OEM TD fronts and progressive rate rears
3. Shocks, Bilstein HD
4. Weight, A good reason to switch from auto to manuals :D

Relatively stiff bar in rear will loosen up the rear end. I think FI said 15mm in back gives neutral steer.

Twalgamuth autocrosses, he could prolly speak to appropriate mods.

GL finding a 15mm.

Silly question; do you really want to try to redesign the suspension on a W123 to turn it into something else?

It's a 25 year old, 4000 pound, midsize sedan that wasn't designed as a "sports sedan." I have HD shocks on mine with stock suspension, and they handle as intended (with a fair amount of body roll). These are not sports cars and they never will be; if this CD really has 14k original miles, don't screw it up with modifications that the next owner will have to remove.

Craig, I was gonna ask the same thing. My 300CD does not have anything like excessive body roll at 148K miles. I just replace the bushings and shocks. I like it just the way MB made it. "Excessive body roll" is a sign somethin' ain't right!

Either that or his idea of "excessive" isn't realistic for this car.

That's what I was getting ready to say. My first instinctive answer to the question was "Buy a car that rolls less." Decided not to say it because it would start us down one of those "Why can't everybody just answer my question politely instead of bashing my ideas" slippery slopes, but it seems like in the long run it'd be a LOT more efficient to just use the car for what it is and buy something else that does a different job better.

Yup, that's why I waited until he had a bunch of "technical" answers already. My first instinct was to just say; go buy a porsche.

This is always a personal choice type thing. Personally I *LOVE* the way my w123 handles.

Craig: by putting on the HD shocks you have already changed the suspension, so your argument is without a point.

Other than lowering springs all of my components are OEM. If you look at the combination of shocks/springs available for the w123 your arguments became even more moot. Clearly what MB "designed" was for a variety of roads in a variety of situations. If you think your Federal CD is setup the same way it would be for German roads.... Or African roads....

I should also point out that I like the stock suspension, especially on the 240d as it is an unassuming car. The turbo 300d however has quite a bit more power and torque.

I understand your point, but I consider shocks more of a maintenance item than a modification (I also use different size tires than recommended). Nothing I've done couldn't be reversed in a couple of hours for a few $100. I just suspect that the OP either has a problem with the car or he is trying to make it do something it was never intended to do.

I don't think I would describe a 300D turbo as having "quite a bit more power and torque." :D

For a few grand you can get close to 300hp out of it. I would consider that quite a bit more. Even with stock components it can be tweaked to make quite a bit more. Or maybe you just drive on curvy roads every day like I wish I did.

...or I could just drive my 300HP W211 and let the W123s do what they were designed to do. ;)

Doubt any chicks are going to be telling you how cool your w211 is.

That's OK, my wife won't let me drive "her car" anyway. :confused:

in my coupe, I have the lowering springs, I just recently replaced rear shocks. all sway links are new. It still has a lot of roll but its tolerable. the 17" wheels with low profile tires made my car look nice but the ride was harsh and no fun and it really didnt handle any better. I now have 15's at stock diameter and like it much better.

I guess you must be dead then. The rest of us with wives still like it when chicks come up to us and tell us how cool our cars are.

She doesn't care about that, she just doesn't want me to mess up her car. :D

My thinking is along the same lines....... Either there is a worn suspension component, such as idler arm bushings, etc... or rear control arm bushings, or unrealistic expectations.

With a car this heavy, major suspension mods are likely to result in a vehicle riding as rough as an empty 5 ton truck and still unresolved "body roll" if there is a worn suspension component.

How much body roll is too much? Expectations have to be realistic as mentioned.

http://www.benzworld.org/forums/atta...t-p0004889.jpg

http://www.benzworld.org/forums/atta...t-p0004878.jpg

Search YouTube for the W123 Faszination videos showing the W123's doing slalom runs at high speed.

The C123's dimensions, for reference:

http://i19.photobucket.com/albums/b1...r/SCAN0515.jpg

Ok guys .... you may have been a little hard on the guy with some of those opinions..
Has anyone read the Factory Shop Manual concerning cars ( and I do not remember the quaint nomenclature it used ) ' built for severe operations.. like countries with bad roads...
that stuff may just bolt in...
however , I would be interested in Winmutt telling us how many hours HE thinks changing out the front anti sway bars takes....

The service manual says it's close to 18 hours. I certainly think it can be done in less.

1. stiffer sway bars.
2. lowering springs
3. More aggressive Dampers
4. Smooth driving.
5. Drive more slowly. (whats the fun in that?)


I just happen to be licensed road racer and agree with VStech. A certain amount of body roll is good. weight transfer is needed, and supple suspension makes a car more forgiving. A stiffer rear bar will reduce weight transfer and lends itself to understeer.

I would like to improve the handling performance of one or more of our Mercedes but am very concerned to not radically change the character of the car. I am not a purist by any means, but I spend a fair amount of time modifying race cars and then getting them to work in a variety of scenarios. Once modified, some cars seem 'moody' as mods make them happy in one scenario but miserable in another.

Once I drive a W123,124,126, 210 with lowering springs, and dampers, I will have a better opinion. For now, I am able to drive each of our Mercedes at ridiculous speeds on racetracks, and outside the limits of our laws on the street (when safe). This being the case, I dont place a high priority on making such mods.

note to anyone considering making changes, adding components that dont compliment each other will make for an ill handling machine. Choose wisely, and be prepared to make changes again.

Fitting a stiffer rear bar will promote oversteer.

A mercedes is designed to be very very neutral with a touch of understeer because understeer is safer than oversteer on the highway (or race track).

To improve handling I recommend:
1. make sure the suspension is in good condition.
2. Add hd bilsteins or Koni shocks.
3. Excellent tires

For most folks I would recommend stopping at this point.

If you still have a bug you can cut some spring off. this is inexpensive and will lower the car and make the springs stiffer.

Heavier sway bars front and rear would be the next most cost effective solution in most cars but none are avalable for the 123 chassis so your best solution is having bars bent or swapping in wagon bars front and rear.

Lowering springs are another way to help some but are virtually unobtainable.

For the cost of modifying your 123 to really handle significantly better you can by a ten year old Miata and drive that when you want to carve up corners. Come to think of it I have a 99 Miata I will sell you or my old 280e euro autocrosser which had h and r lowering springs on it and hd bilsteins in front and Koni adjustables in back.;)

Really for street driving it is hard to beat a stock benz with all the components up to snuff with stock sized tires.;)

Cutting off spring will not make the spring stiffer. It will only lower and give the suspension there less travel distance.
If you want stiffer proper springs you should buy new ones with ' a larger wire size' as MB refers to the various stiffness options.
There are posts I think where I posted the chart from the FSM on this subject.

I used to work at a spring and brake shop.. which did all the spring work for the City Of Austin... trucks regularly have to have new springs ... or reconditioned ones.. which involves some serious equipment and experience for heat treating in order to give the length of service you expect from them.
The FSM also gives full instructions having to do with car height off the road... and changing that changes the geometry of the steering.

http://www.benzworld.org/forums/atta...t-p0004889.jpg

http://www.benzworld.org/forums/atta...t-p0004878.jpg

[QUOTE=MBeige;2634539]How much body roll is too much? Expectations have to be realistic as mentioned.

Yeah my car rolls less than this, because i do not push it on mtn roads at speed. Only place like at 40 mph 90 degree off ramp where i wont go off the cliff. when I do it rolls.

I have finished fixing all the small broken engine stuff from the car sitting in a garage for a long time. 7 years in a garage then towed to the shop and drain the diesel, and 2200 dollars of maintenance and detailing and then 2 more years sitting in a garage in one of his 23 houses. I have fixed the broken window regulator, leaking fuel line, vacuum leak, rusty hood springs, new thermostat, new akebono ceramic brakes and brake lines. The car is mechanically without any problems now. It brakes unbelievably straight and stable. I like driving with the big steering wheel and especially braking the car.

I do not think anything is wrong with my car.

I do not like the roll, and would like to dial in the car, so it rides the so called rail yet keep most of the mercedes touring ride we like.

I heard that bilstein HD in fronts and bilstein comforts in the rear works well.

I read that Winmutt bought vogtlands and then he cut the Vogtlands.

i read shocks dont really decrease roll much and i have some comforts with only 14K miles on them that if I keep, could save money to buy sway bars.

If you want to ' dial in' what came with the car... put new springs on all the way around. They are relatively cheap and on the cars I have done this to it made a huge difference in feel... to jump to the anti sway bar before springs would not be logical.

My W123 pretty tight with new rear springs (one broke, replaced both), HD shocks all around, and the front suspension/steering completely replaced. After several $1000 of work, it's probably pretty close to it's original handling capability. Of course, just about any modern car will handle better than a good 25 year old car; my W211 will run circles around it (active suspension, traction control, better tires, better brakes, three times the power, etc.). If you expect significantly better handling, you're starting with the wrong car. If you introduce oversteer and drive it near the limit, you will probably wreck it sooner or later.

1. BBS RS 7 x 16 Nexen N3000 205 50 16 ET 24 Diameter =24.1
2. BBS RS 8 x 16 Nexen N3000 245 45 16 ET 11 staggered set D = 24.6
3. OEM oil pan protector
4. KMAC Camber adjuster rear
5. front 3 inch spring cut
6 rear 3.5 inch spring cut

1.
2.
3.
4.
5. Wait for group buy perfect sway bars front and rear.

Have fun, keep the original parts.

racers and mechanics agree?

A. How much for TD springs front and back with new bushings?

B. How much for TD springs front with new bushings?
B. How much for the Vogtland rears? new bushings?

A or B good ideas if I cut them.

A. Keep the Bilstein Comforts

B. Buy a new set of HDs front
B. Keep the rear Comforts

C. Buy 4 new HDs
C. Toss the Comforts.

The typical front turbo TD spring is the same as the typical Turbo D spring. The rear TD spring is going to be shorter.



.

[QUOTE=leathermang;2634896]Cutting off spring will not make the spring stiffer.

I disagree with this. Hey I could be wrong but everybody else says cutting off some of the spring will make what is left stiffer in its compressive state. It is true it reduces wheel travel and will change the steering geometry a little, but the car is designed to operate with up to about 1200# load so operating correctly with different ride heights is part of the reality of suspension design if you are working with springs and passive dampers.

Now if you have adustable air bags and the necessary controls you can keep the ride height constant but we are not talking about that.

Having autocrossed my 84 500sec and my 84 euro 280e I can tell you that even though a benz rolls a lot in a corner, it will still corner pretty well. In autocross the time it takes for the springs to compress and expand is considerable compared to really quick cars but you have to start turning further away from the cone to give it time to compress. Once the springs are compressed the car will corner pretty decently.

Stiffening everything, springs, sways and shocks will give quicker response between turning left and right as especially in a slalom.

In my 99 MIata I was running the last two years in CS which allows anything you want in a shock as long as you keep the stock holes in the chassis and anything you want on the front sway but you have to keep stock springs. You also must keep the stock sized wheels but any tire you can cram on there is allowed.

I was running a very large front bar and As allowed the stock rear bar. The problem at the limit, especially as the Hoosier slicks wore was understeer. To balance the car I had to stiffen the rear shocks.

The ES Miatas running the same tires I was running in
CS had huge lean angles but were quicker than my car. They leaned so much you would swear they were going to go on over. You can see quite a bit of the bottom of the car (it seems like) when they go through a tight corner and the slicks are hot and sticky.

My point being that for street use, all talk about handling is pretty academic. What folks are really doing when changing all this on a street car is changing how the car LOOKS, and the impact on actual handling is pretty much minimal.

Also if you want to make it feel quicker put on a smaller steering wheel. This will make it feel quicker on the steering and the difference is dramatic. I have not done this with any of my benzes but did it with my 74 Saab 99.

Cutting a spring will not change the torsional stiffness of the wire. Counterintuitively, however, it will change the load/deflection relationship of the spring as a whole, making it stiffer (less spring deflection for a given load). Some head scratching and free body diagrams are involved, but it's neat when the light comes on about this.