[andrewbr]

I just installed new suspension on my car (Koni Orange + Eibach ProKit), and used the recommended bump stops from the various lowered car threads around, E36M3 front and Z4M rear. The fronts look good, but the rears are quite long and seem to take up too much shock travel. Looking back at the threads that discuss this, the regular Z4 bumpstops appear different and slightly shorter than the Z4M variety.

The rear of my car does seem a bit firmer when going over larger bumps, I'm assuming I'm hitting those bumpstops and am wondering if shorter ones would help. I'm wondering if there are any other shorter bumpstops I could or should try, just get the Z4 variety, cut the Z4M ones I have now by some amount, or if there's some other option out there anyone has had success with?

I did also install the firmer Monroe upper shock mounts which could be the cause of this and may try switching back to OEM foam ones, but I want to switch out one thing at a time here to test the effect on ride quality.

Thanks

[wrevilo]

Seems like you have undertaken a near complete refresh. The rear bump stops are longer and do form an important part of the overall suspension design. I used part 33536788905 on my E92 335i.

[whyzee125]

People commonly recommend Z4M rear bump stops but the "correct" ones are actually Z4 NON M ones. Part number 33536770350

EDIT: the post above is correct, looks like that's a newer iteration of the same non M part.

[andrewbr]

Thanks for the info, that's sort of what I had expected, back to ECS!

[mattanderson]

Originally Posted by wrevilo

Seems like you have undertaken a near complete refresh. The rear bump stops are longer and do form an important part of the overall suspension design. I used part 33536788905 on my E92 335i.

Originally Posted by whyzee125

People commonly recommend Z4M rear bump stops but the "correct" ones are actually Z4 NON M ones. Part number 33536770350

EDIT: the post above is correct, looks like that's a newer iteration of the same non M part.

Thank you for the clarification. There is so much confusing info and this answers one point of confusion I had after my full suspension refresh.

I bought the Z4M ones after lots of apparently misguided research, and after comparing to normal spec bumpstops and seeing how little travel they add, decided to just cut my normal ones as described in Eibach's instructions (instructions specify cutting 25mm, I cut cut ~20mm since that's where the extra "node" ended + I added 10mm of travel with "poor man's" Dinan rear mounts).