I'm at the end of my ropes with this front suspension issue on my F31 with KW Street Comfort coilovers. The coil bind is seemingly getting worse over the last 5K miles, and crashes over any road imperfection.
The streets of Los Angeles are not bad, not great either, and they the ride is fine at lower speeds and more gradual road obstacles. But man... any small road transition or tiny pothole and WHAM!
It's the coil travel that binds, same issue as this guy:
https://f30.bimmerpost.com/forums/sh....php?t=1830408
We've tried every damper setting and height adjustment under the sun.
KW support will only RMA the springs for the exact replacement.. which has me worried that I would just end up in this same situation again.
So before I go accepting my fate, and purchasing some new shocks with H&R springs...
I had a crazy idea:
What if I added a second spring to the front? Create a dual rate setup.
Add a tender/helper spring that does not fully block under load and adds some stroke when engaged.
There is a solid 3-4 inches of adjustment left on the shock body to lower the perch.
What do you think be downside of adding another spring like this one from Eibach?
https://eibach.com/product/0200.250.175-550
It's an additional progressive spring, but the block load weight rating is lower than my corner weight... so would I even get any stroke out of them?
Of course, there is always the option of a stiffer static rate spring.
The current KW front progressive springs are rated at 226 lbs/in, so based on the formula:
(upper rate x lower rate) / the sum of the upper and lower = active rate.
If I add a static 3" spring that is 400 lbs/in to the primary spring, I end up with a dual spring rate of about 145 lbs/in. Which doesn't sound right to me.
Thoughts? Prayers? Dumb idea? Thanks.