Quote:
Originally Posted by thecadman99
After a lot of worrying about it, looking at the ridiculous prices for new, smaller bumpstops, and after getting tired of my "bumpy" ride, I decided to take out my rear bumpstops and cut them.
I should add that I am running Eibach pro-kit springs that have a bit of a drop, along with BMW performance suspension. Its very stiff and always soaks up the small stuff fine, but larger stuff is too stiff for this old guy. Could it be the long bumpstops are contacting too soon?
Here are my factory bumpstops as removed today:
I didn't really want to cut them as the taper and the inside (with the slight hollow area as shown) is designed to progressively start adding the bump resistance.
Still stock here, but you can see the undercut inside the hole.
So I bit the bullet, cut off the tip, and cut a taper with my trusty swiss army.
It looked pretty rough, so I got out my rotary tool, and a barrel sander, then a round bit to smooth out the taper, and add the undercut back into the bumpstop:
Here they are, ready to go, not perfect but hopefully workable. They both popped right back into the shock sleeve without problems.
I used this opportunity to coat all my rubber shock hardware (including the stops) with protectant.
Now, you probably want to know if it improved the ride? Um, I dunno yet! I'm heading out with the missus to watch Iron Man 3 so I'll post how it rides on the way back.
I didn't have any spring compressors so I couldn't do the front but I fully plan on doing the same thing as soon as I can borrow the compressor from my friend.
UPDATE: After test driving it was obvious that cutting the stops made a big difference. At first I was a little worried, going around the first curve I could feel the rear was "looser" not bad but it definately had some wiggle that wasn't there before. After a couple of miles through some of the worst road undulations, and transitions I was very happy with the way the rear was soaking up bumps and NOT bouncing (and so was the missus!).
To think I was ready to throw money at this problem when the bumpstops were the main cause of my overly firm suspension.
I took a speed bump straight on, and my wife even noticed the difference between the front and rear and how the rear soaked up the bump with minimal drama. I am super happy with the results of such a small adjustment. |
Sorry to resurrect a 8-year old thread!
I am looking to do the same on my E92 SE (100% stock and not lowered) as the rear is feeling firm even after fitting new Bilstein B4 (non sport) shocks at the rears... (front is SACHS shocks).
In your original post, there seems to be no pictures hence can you clarify where exactly did you cut off the material on the bump stop? (On the top or bottom?)
Also, how much did you cut off in height?
Depending on how much is cut off, my assumption is that anything under 1/2" would be okay for the shocks as I don't think an extra 1/2" of travel would allow the shock to bottom out over deep bumps and therefore bend internal parts like the piston etc... These E9x cars basically sit on the bump stop at ride height which is very strange...At least the BMW engineers should have had some extra shock travel for the SE spec models!
Clarification on the above would be highly appreciated. Thanks.
