Sway Bar Upgrade
 

I am looking at sway bars next, and haven't been able to sort out one thing in my online research. Here's the question: are the sway bars included in the Eibach kit that's available for E53s (34mm front, 26mm rear) an upgrade over the stock 2006 sport package or no? Thanks in advance.

My notes from Eibach say they are stiffer than the stock sways on the later model E53 sport package SAVs. So in short yes they would be an upgrade.

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ECS Tuning

The kit you listed seems to be discountinued by Eibach (they sell front and rear separately now . . . if you can find the front bars) but it is an upgrade over the stock sway bars.

I was planning to get the same kit but just found out why you can't buy the kit on most sites. ECS Tuning has the kit listed on their site but not sure if it is available.

Anyway, The rep at autoanything.com just informed me that Eibach discountinued production of the front bars because there was a design flaw with the US production - he called Eibach. The German made version has no issue(s) but are hard to find and they don't carry it.

Looks like I'll be looking at a dif. manufacutre for a kit. Let me know if you know of any other companies. The only one I found that carries the sway bars for the X5 is Eibach.

BTW, I have an 05 4.4 - black!

Hey ECS . . . is it true that Eibach had a design flaw on the front sway bars? Can you call and confirm?

My notes say they changed the kits after the initial run, I don't have anything noting a design flaw most likely it was just a change in machining. The kits we have on the site are the most recent run of the kits.

I also have the front and rear bars available separately HERE is a link to all the sways for the E53. All parts are showing as available.

James with ECS

Why do people change front and rear sway bars?
I mean, the X5 understeers, so installing a stiffer rear bar would help by inducing a bit of oversteer.
Going with 2 bigger bars would make the X stiffer, but the understeer would still be present.

Cool. Looks like I'll be picking up a kit from ECS . . . your prices are competitive to other vendors.

I installed the Eibach kit on my '04 3.0 two years ago. I already had the 20" setup on it. The sport package 3.0 X5 was much more stiff after the upgrade and tracked more directly in highway transitions. Turn in was quick and body roll through the turn was significantly lower. The last thing I noticed was the added response I received from the X Drive front wheels. In pretty much any situation where I wanted to add throttle in a turn, I was able to do so sooner in the turn and with greater response from the driven front wheels than before. It makes sense- the vehicle is flatter, the wheels are more planted, the traction is better. But the application of it was surprising nonetheless.

I liked the setup so much that I moved the sways over to my 2004 X5 4.8is when I bought it last year (almost one year ago). I replaced the 3.0's sways with the ones from the 4.8is (same size for SPP 3.0's/4.4's). I drove the 3.0 to the shop with Eibach and back home without. I was surprised at how comfortable and responsive the 3.0 was with stock sways. It still provides a better balance than anything else its size. It felt much less aggressive, but still very capable.

On the 4.8is, the sways did not make such a difference. Or if they have, I just have yet to really feel it. One of the key differences in my two X5's was that the 3.0 was early production with the smaller sunroof. That means less weight up top to reel in with the 3.0. It's why *I* think the thing was so much more responsive than the 4.8is with all the glass. I love that smaller roof. I often see my next door neighbor tooling around in that old X5 and wonder if they've completely ground McDonalds fries into the seats. Could it be rescued?

Adding to the differences may also be the 4.8is' softer air suspension and drive by wire steering. The thing feels less connected to the road by design, so it would follow that the sways would improve, but not quite gain the same feel as they did on the 3.0.

With the Eibachs on the 4.8is, it still has all the grunt and it still grabs better out of a nice turn. Highway transitions are not as soft, and roll is reduced. But only so much can be done to challenge the affects of simple physics.

All in all, a nice upgrade for ~$500 in parts. The install is a killer, though unless you know some mechanics' tricks that I do not know. The way I looked at it, swapping the kit saved me about $400 after labor over just buying a new one for the 4.8is. It was worth it, and I like the results on both cars.

Two reasons why I know sway bars, for street cars, are bullshit.

1. You essentially tie down your independent suspension, and make it almost solid axle. So if you live anywhere similar to the roads of NYC, you might as well save your money just based on this and not read any further.

2. Your cars main control of body motions, is through the springs and shocks, sway bars negate their function by not letting them work properly.

On a street car, it is a mental thing. Do you really think German engineers, the ones who designed your car, the millions invested in RND, don't you think they would have put in bigger bars if they could make the Ultimate driving machine more ultimate?

Well I used to race cars when I had time. I also drive harder when I can, and push limits pretty often. How many of you drift your X through a turn, on the street, with cars parked on both sides? Yea sway bars will help you drift easier. Sway-bars will also kill you, and your car when the weather is bad, or snowy. You know that twisty on ramp you take all the time? Do you like to accelerate through it? Won't you be shocked when some sand or shit is on the road and your car slides out from under itself without warning?

Always remember this, if your car is not leaning, that means it is transferring all that load into the outside wheels, while your inside wheels if fighting to stay connected on the ground. The outside wheels are not getting loaded up (more grip), as when the car is leaning, they are getting pushed sideways. So your car won't be leaning, it will be sliding. You essentially will be making your tires into the springs, because you negated the real springs with sways. How many directions of grip, and function were your tires designed to do? Most rally cars don't use sway bars at all. They like their independent suspensions.

My old car used to spin out like a mofo with upgraded sway bars. Scary spin outs, as in no warning, and very sudden. My friend tracks his e30 with no sways at all. It is all in the spring / shock tuning / setup. A lot of race cars don't use sways at all. That's why they make 2000lbs springs.

Sway bars main function seems to be designed for less body roll, which is not a bad thing and works, in conjunction with soft-er springs and shocks. So that way you get a street car that can negotiate bumps and road imperfections without rattling your brain. At the same time, give you the sensation of stability with reduced body roll. But it is engineered as a package. One effects / balances the other.

All in all, don't mess with what was engineered by people designing a car as a whole. If you think sways will help you, put them on, but I guarantee you that if you learn how to drive closer to the limits, you will find that getting bigger sways is actually a downgrade, if not dangerous. I speak from experience.

Recap. Sways are bullshit on a street car, or SAV.
1. Make your ride worse.
2. Make your tires become the springs.
3. Do not improve handling. Maybe slow speed handling, whatever the hell that is.
4. Change dynamics of a car without addressing all the other points in the suspension geometry.
5. Long term durability? Questionable, I don't know anyone in an X with broken sway mounts, but time will tell as these cars become cheaper and more people buy these "upgrades". (your sways are not twisting as much, so your mounts and links, better be able to handle the extra twist put on them)

Long post, sorry.

Interesting take . . . thanks for sharing your experince. So my mods for my 05 4.4 will be limited to changing the front OEM struts to the Bilstein HD and loweing with the H&R springs for now. I'll hold off on the sways until I get a feel of the new suspension.