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BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Suspension | Brakes | Chassis > I cannot for the life of me understand why my ride is so rough



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      08-31-2013, 09:46 AM   #1
miringrains
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I cannot for the life of me understand why my ride is so rough

So I'm running megan racing springs on bilstein struts. When I just put in the struts (I was running stock struts) the ride improved on bumps (such as gas lines on highways). After a week it went right back to normal, and I'm so tired of it. Every single bump I hit on the highway sounds like I ran into a curb, I really have no idea why this happens. FYI my bilsteins do not run bumpstops.

Can anyone tell me why the ride was tolerable for a week, and then it defaulted to crappy again?
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      08-31-2013, 07:55 PM   #2
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Do u have run flats? First thing to change for a smoother ride.
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      08-31-2013, 09:11 PM   #3
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I don't understand, did you have the Megan Racing springs before you installed the Bilsteins?
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      08-31-2013, 11:17 PM   #4
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How much drop do the Megan's give (link please)?

Also which specific Bilsteins are you running?
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      09-01-2013, 01:22 AM   #5
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1.Could be because spring rate is high

2. bilsteins may not work with megans drop.

3. add some bumpstops? maybe it will help with major bumps.

unless it was installed improperly. not much you can do. try different springs.
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      09-01-2013, 07:55 AM   #6
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One possibility (maybe remote in your case) with the bilstein sports is, due to the design in front (inverted monotube inside a McPherson strut housing), air can get trapped inside the lower part of the housing. This gives you 2 things, a little extra ride height and a somewhat softer effective spring rate. Until the air bleeds out over a few days or weeks of driving, then you are sitting on whatever your springs and bushings were before.

If you look at the "shaft" of the bilstein you will notice it is extremely thick, that is because even though it does slide up and down inside the housing, it is actually the shock body itself in there, the fluid, gas etc is inside that shaft. A smaller diameter ordinary shaft is bolted to the inside bottom part of the housing. The piston is attached to this one and it is the main body that slides up and down inside the housing around the piston. This is why you CANNOT add bump stops to front bilsteins, they have them inside already (at the bottom of the little shaft) and the exterior shaft is too thick.

So air gets trapped under there, this is one reason bilstein instructs you to fully compress new shocks before installing. It is a hassle though, as when new each time you jack up your car with front at full droop it sucks some air back in and needs to settle a bit afterwards. Goes a way as the seals break in.

Anyway the mystery here is not why they are harsh, I would expect Megan race + bilsteins to be harsh. The mystery is why they were ever soft, and the above is the only thing I can think of.
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      09-01-2013, 09:42 AM   #7
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Quote:
Originally Posted by miringrains View Post
So I'm running megan racing springs on bilstein struts. When I just put in the struts (I was running stock struts) the ride improved on bumps (such as gas lines on highways). After a week it went right back to normal, and I'm so tired of it. Every single bump I hit on the highway sounds like I ran into a curb, I really have no idea why this happens. FYI my bilsteins do not run bumpstops.

Can anyone tell me why the ride was tolerable for a week, and then it defaulted to crappy again?
What spring rates you runnin' and were the Bilstiens matched to your springs?

Inspect your suspension lately? Stock arms?

Need much more info....
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      09-06-2013, 02:39 PM   #8
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and did somebody tell you megan racing stuff is legit "performance" parts? cuz if they did, that person lied to you. lol
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      09-09-2013, 04:09 AM   #9
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It takes time for new springs to settle after installation so the intial feeling is not accurate.
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      09-09-2013, 03:00 PM   #10
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I say there are a lot of variables that go into a harsh ride quality. Quality of springs, or rates, or progressive/linear all play a part. As stated above, sometimes bump stops will help with harshness over bumps. Possibly you have your strut rebound to high? How many miles are on your car? Subframe bushings going out? I would just have it professionally inspected.

-Mike
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