Eibach Anti-Roll Kit (Sway Bars)
Newbie
Joined: Jan 2012
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C250
Hi all,
This is about as recent as I can find regarding info on anti-roll bars (ARBs) for the W204.
I currently own a C250 sedan (2012). Was wondering if anyone has done up front/back ARBs for this same model? So far, I seem to be only able to read on inputs for C300s and C350s.
As gathered here, the part number seems to be # 2578.320 for both Eibach front & rear.
I'm don't live in US so it would be a great hassle if I had to return my online purchase. Anyone with the same model and setup, please give me some feedback if the installation works exactly like described in here.
Much appreciated!
This is about as recent as I can find regarding info on anti-roll bars (ARBs) for the W204.
I currently own a C250 sedan (2012). Was wondering if anyone has done up front/back ARBs for this same model? So far, I seem to be only able to read on inputs for C300s and C350s.
As gathered here, the part number seems to be # 2578.320 for both Eibach front & rear.
I'm don't live in US so it would be a great hassle if I had to return my online purchase. Anyone with the same model and setup, please give me some feedback if the installation works exactly like described in here.
Much appreciated!
Super Member
Joined: May 2010
Posts: 816
Likes: 21
2008 W204
I am 
. An outstanding mod which really helped reduce roll without negatively affecting ride quality. I did not touch the springs, as I thought they were well calibrated for the vehicle, and I have no interest in changing suspension components just for the sake of lowering the ride height appearance. Now, here's the issue....the front bar installed very easily in less than an hour. The rear bar requires dropping the rear subframe (Eibach, MB, and tirerack all agree on this...no way around it), estimated at about 3 hours of labor, which is more than the cost of the bar itself!!
So far, I have the front bar in and the rear bar from the kit is still new in the box. But, even the front bar makes a great improvement....less roll and quicker steering response. Tightening up the front would be expected to result in increased oversteer, but I found that unless really pushed aggressively, the car does not plow, and then, only slightly. I am debating whether to ever install the rear bar at $300 in labor alone......
If you are really concerned about handling and not just making the car look lower, try the bars first before doing the springs. And, the front bar has two attachment points...use the closer-in attachments for greater anti-roll force.
. An outstanding mod which really helped reduce roll without negatively affecting ride quality. I did not touch the springs, as I thought they were well calibrated for the vehicle, and I have no interest in changing suspension components just for the sake of lowering the ride height appearance. Now, here's the issue....the front bar installed very easily in less than an hour. The rear bar requires dropping the rear subframe (Eibach, MB, and tirerack all agree on this...no way around it), estimated at about 3 hours of labor, which is more than the cost of the bar itself!! So far, I have the front bar in and the rear bar from the kit is still new in the box. But, even the front bar makes a great improvement....less roll and quicker steering response. Tightening up the front would be expected to result in increased oversteer, but I found that unless really pushed aggressively, the car does not plow, and then, only slightly. I am debating whether to ever install the rear bar at $300 in labor alone......If you are really concerned about handling and not just making the car look lower, try the bars first before doing the springs. And, the front bar has two attachment points...use the closer-in attachments for greater anti-roll force.
Pardon my ignorant question, but does the C300 Sport come stock with anti-roll bars? If so, do you have to remove them to put in the Eibachs?
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From: Southwest USA
Another round of ICE
The C300 does have stock front and rear anti-sway bars, which are thinner than the Eibach upgrade. The new Eibach bars replace them. The kit comes with the necessary new bushings, but also uses the original clamp around the front bushings, which has to have its rivets drilled out. I still have my set of original Sport antisway bars, which are probably thicker than those on the Luxury model, if anyone wants them, but I cannot state with certainty what other models they would fit...4matic, for example.
By all means, go ahead with this mod. Between this and the new steering wheel, these are the biggest smile-makers I've experienced!
Last edited by Sportstick; Jun 9, 2012 at 02:55 PM.
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From: Delaware
2004 Mazda6, 1993 RX7
Yes, the rear bar was installed quite a while ago. The rear bar added another significant step in improving overall responsiveness and helped return the car to the neutrality that just stiffening up the front diminished. In fact, during very aggressive cornering, the rear end may step out a bit just before the apex. A touch of oversteer is much more entertaining than understeer if you know your car and have the skills to handle it. However, up to that point, the car has a "slot car" feeling, staying flat and quickly reacting to steering input. I love it. ... but I cannot state with certainty what other models they would fit...4matic, for example.
Originally Posted by LeweyLou78
... the Eibach bars are only 2mm bigger in size than the stock sway bars on the sport models so I don't know if the bars make that much of a difference:
Front = luxury 25mm vs. sport 26mm (Eibach = 28mm)
Rear = luxury 16mm vs. sport 19mm (Eibach = 21mm)
Front = luxury 25mm vs. sport 26mm (Eibach = 28mm)
Rear = luxury 16mm vs. sport 19mm (Eibach = 21mm)
(28/26)^4 = 1.345 , so the 28 is 34.5% stiffer than the stock 26 up front. At the rear the 21 is 49% stiffer than the stock 19, and those are significant changes LeweyLou !! And, the 2nd hole option on a bar's end to shorten the lever arm, is often considered to be like adding 1mm in dia.
Then there is the "stiffer mode" of the bar in reducing roll, which is 2X that calculated rate that represents a single wheel moving up (ie over a brick) with mimimal chassis motion.
For rwd cars, the front bar is largest and mainly controls body roll. The rear bar basically is sized for the desired roll stiffness balance. Like Sportstick, I bought an Eibach bar set ( for my rwd rx7 track car) and first just replaced the front bar, expecting gross understeer. Instead I noticed less roll AND much quicker turn-in. Only at high G loads did the understeer show-up.(testing done on highway cloverleaf, low traffic time)
When I replaced the rear bar, there was no significant added roll resistance, but it behaved just like Sportstick said.
.
Last edited by kevink2; Jun 11, 2012 at 02:11 PM.
Super Member
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2008 W204
All very interesting. I'm thinking I may just get the front bar, it seems the rear bar isn't worth the time and money. I rarely/never push my car to the point where I experience oversteer.
Does anyone know if the Eibach front sway bars work on 4matic cars?
Does anyone know if the Eibach front sway bars work on 4matic cars?
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From: Southwest USA
Another round of ICE
When you contact Eibach or tirerack.com, they can tell you about compatibility with 4MATIC. I'm sorry, I do not know.
Last edited by Sportstick; Jun 10, 2012 at 11:31 PM.
Junior Member
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C300 4Matic
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From: Southwest USA
Another round of ICE
Basically, a C63 lookalike, but same diameter as original. Actual C63 is an inch less in diameter. Keeping the diameter saves big bucks by reusing the original air bag hub, and also doesn't completely block the sight line to the top of the gauges.
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MBWorld Fanatic!
Joined: Sep 2008
Posts: 1,331
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From: Delaware
2004 Mazda6, 1993 RX7
MBWorld Fanatic!
Joined: Sep 2008
Posts: 1,331
Likes: 9
From: Delaware
2004 Mazda6, 1993 RX7
But to stay more neutral at the limit with front and rear bar upgrades, the following options come to mind:
1) elongate the hole on the Eibach rear bar end like a slot, that extends the length of the lever. A heavy washer with attached "key" would keep the increased lever position. Stiffness is inversely proportional to the square of the lever arm.
2) consider the Eib front (28mm) and C63 rear (20mm), assuming it fits.
4MATIC: All Eibach current literature states bars will not work on 4matics. So only upgrade there would be is for the C300 4MATIC LUX, going up 1mm by using oem C300 4MATIC SPORT bars. (need to verify)
.
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2008 W204
MBWorld Fanatic!
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From: Delaware
2004 Mazda6, 1993 RX7
No need to put a knot on your forehead.
If you want to get away from too much understeer, you can simple down size the front bar 1mm by using the bar for the 4MATIC-LUX model. That will reduce front bar spring rate about 17%.
Similar situation:
I had a mountaiin-biking buddy with some open wheel track instruction. He wanted to go to Summit Point Raceway with me for a track day, driving his honda civic sedan.
The day before we went, I test drove his honda in a large empty parking lot, and found show stopping understeer ... would be a bore at the track. I quickly removed the vertical links to the front bar, and fixed the bar with some romex 12 ga wire.
Back to the parking lot, the car roll was huge, but it stuck to the corners like glue .. he had a blast at the track with no front bar.
.
If you want to get away from too much understeer, you can simple down size the front bar 1mm by using the bar for the 4MATIC-LUX model. That will reduce front bar spring rate about 17%.
Similar situation:
I had a mountaiin-biking buddy with some open wheel track instruction. He wanted to go to Summit Point Raceway with me for a track day, driving his honda civic sedan.
The day before we went, I test drove his honda in a large empty parking lot, and found show stopping understeer ... would be a bore at the track. I quickly removed the vertical links to the front bar, and fixed the bar with some romex 12 ga wire.
Back to the parking lot, the car roll was huge, but it stuck to the corners like glue .. he had a blast at the track with no front bar.
.
Super Member
Joined: May 2010
Posts: 816
Likes: 21
2008 W204
No need to put a knot on your forehead.
If you want to get away from too much understeer, you can simple down size the front bar 1mm by using the bar for the 4MATIC-LUX model. That will reduce front bar spring rate about 17%.
Similar situation:
I had a mountaiin-biking buddy with some open wheel track instruction. He wanted to go to Summit Point Raceway with me for a track day, driving his honda civic sedan.
The day before we went, I test drove his honda in a large empty parking lot, and found show stopping understeer ... would be a bore at the track. I quickly removed the vertical links to the front bar, and fixed the bar with some romex 12 ga wire.
Back to the parking lot, the car roll was huge, but it stuck to the corners like glue .. he had a blast at the track with no front bar.
.
If you want to get away from too much understeer, you can simple down size the front bar 1mm by using the bar for the 4MATIC-LUX model. That will reduce front bar spring rate about 17%.
Similar situation:
I had a mountaiin-biking buddy with some open wheel track instruction. He wanted to go to Summit Point Raceway with me for a track day, driving his honda civic sedan.
The day before we went, I test drove his honda in a large empty parking lot, and found show stopping understeer ... would be a bore at the track. I quickly removed the vertical links to the front bar, and fixed the bar with some romex 12 ga wire.
Back to the parking lot, the car roll was huge, but it stuck to the corners like glue .. he had a blast at the track with no front bar.
.
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Joined: Sep 2008
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From: Delaware
2004 Mazda6, 1993 RX7
Do nothing if you are happy with turn in and understeer at the limit.
But for less understeer at the limit, and faster lap times with higher G's in the corners, reduce front bar a bit. Read the Honda example.
.
But for less understeer at the limit, and faster lap times with higher G's in the corners, reduce front bar a bit. Read the Honda example.
.
Last edited by kevink2; Jun 15, 2012 at 04:01 PM.
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From: Southwest USA
Another round of ICE
We have to define some terms here. "Tight" is a common word for understeer, while "loose" is for oversteer. (Listen to some NASCAR chatter.) So, reducing the front bar thickness makes it less "tight" as in less understeer, bringing the car back to neutrality...a good thing. A tight/understeering car is more undesirable than a neutral or loose car, as you can at least deal with oversteer by backing off the steering wheel when the rear breaks loose. With an overly tight/understeering car, once it starts to plow, you have a problem on your hands.
Kevink2's suggestion will bring the car back to neutrality, but the increased body roll you experience might be subjectively interpreted as not handling as well, even though as he said, the actual handling (ability of the car to follow the intended path) down where the tires meet the road is improved. Think of it as more body roll on top/better handling at the surface.
Kevink2's suggestion will bring the car back to neutrality, but the increased body roll you experience might be subjectively interpreted as not handling as well, even though as he said, the actual handling (ability of the car to follow the intended path) down where the tires meet the road is improved. Think of it as more body roll on top/better handling at the surface.
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From: Columbia, SC
W204 2010 C300 Sport/6M
This is the reason racing seats were invented. So when your "loose/sticky" car changes pitch you don't go through the side window onto the street. Good information on this thread.
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From: Washington
10 E63, Sold -07 E63
Sway bars are good for all types driving. One of the things your don't want when doing a road race course type is body roll. Body roll throws off the body geometry when taking turns. It causes your tires to run on the outer edge, throws weight around, causes positive camber, and just so much to consider when you don't fix it. Keeping your car as rigid as possible so that it follows where you want it to go. Subframes upgrades, strut bars, true welds spots through out the body, will help stiffen up the structure. Then dial in a good coil over system, and most important of all tires that can handle temperature changes depending on how many turns your course has. This method is used by most high performance vehicles. The Nismo edition of Nissan does this to their cars, along with the fast lap times of the Skyline GTR on the Nurburgring and many other tracks. If your talking long corners, circle tracks, oblong...etc, downforce aerodynamics with good shocks and springs.. will do.
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From: Delaware
2004 Mazda6, 1993 RX7
"I rarely/never push my car to the point where I experience oversteer."
To which I said:
"Do nothing if you are happy with turn in and understeer at the limit" , assuming he meant understeer, not oversteer above.
The suggestion to drop front bar size 1mm is for race only. Keeping the oem bars will not increase roll, and will keep the quicker turn-in vs installing the Lux front bar, which will have opposite results for both roll and turn-in, and will not get the tighter feel he desires from a bigger bar set.
.
Last edited by kevink2; Jun 16, 2012 at 09:41 PM.
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From: Delaware
2004 Mazda6, 1993 RX7
.
Super Member
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From: Washington
10 E63, Sold -07 E63
Agreed to some point. Most of these add on only correct the driver's short coming. Suspension is a very tricky part of the car. That is why many companies and race companies spend millions on research and still have space for improvement. Every track is different, every car is different, and every driver is different. But the best cure to most is a well educated driver and practiced like you said.
Very good outline for a trailered race car, but mega stiff 3-piece sway bars have no place on road cars, not even 100% stiffer bar sets. Even at the track, my Rx7 with oem springs and an Eibach bar set was faster though 80mph corners with rough track surfaces, vs a more modified version with mega bars. Stiff bars reduce the independence of the independent suspension. Imho, one would do better to invest in driver-ed track-days, than to make a race car for a DD.
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From: Delaware
2004 Mazda6, 1993 RX7
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Newbie
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2008 mercedes C-300 lux
I have a 2008 C-300 that I am installing an Eibach rear sway bar.
Problem, the right side bar bushing bolt is an inch away from the fuel filler tube!
Has anyone installed one of there bars yet, if so, whats the secret?
Problem, the right side bar bushing bolt is an inch away from the fuel filler tube!
Has anyone installed one of there bars yet, if so, whats the secret?
