[rhmarquez]

I've read multiple threads and there seems to be a debate as to getting the Bilstein B6 or B8 with the stock M-Sport Suspension (Code: S704) springs.

On Bilstein's website it claims that for bmw's equipped with Standard Suspension to get the B6's, and for bmw's with Sport suspension to get the B8's. Yet I've read countless posts saying to get either one or the other but with no actual feedback as to why. I read the B6 tends to increase ride-height, and I really would like to keep my current fitment. I would believe that since the B8's shaft is a mere 20mm (2cm) shorter, that it wouldn't cause this height increase.

I ended up buying the B8's since that's what Bilstein says I should use in my car. I also know that the B8's are intended for lowered cars, but then why would Bilstein recommend them for stock M-Sport suspension cars? Will I have issues using them with the stock M-sport springs?

I read people driving older platforms (E90, E92) using them with the stock springs and working excellent, but can't find anything on the F3x's.

[blumagic]

Just free balling here but off the top I think the worst that could happen is that you have extra preload on the spring which could make it ride a little stiffer

[pauli18c]

from my understanding they are the same shock, just different lengths. the M sport is such a mild drop, both should technically work

[SystemOfUrdaW]

[QUOTE=rhmarquez;26478943]I've read multiple threads and there seems to be a debate as to getting the Bilstein B6 or B8 with the stock M-Sport Suspension (Code: S704) springs.

I just got my car back from the shop.
I'm on Bilstein B8 + Eibach low springs.
B8 are suppose to go with lower springs.
Most combo i've seen are with H&R, Dinan, or Eibach.
I have a problem chassis now cause i use to have adaptive suspension.
Gotta code out EDC or install a module to get rid of my problem.
I drive a 2016 340I Xdrive, it's a pain in the ass that for now i can't push that mode button to Sport and Sport+
The shifter to the left and i'm good but it's not the same.
FBO Stage 2 deserves better.

[rhmarquez]

For anyone interested in having this setup (B8's with factory M-Sport springs) this is how it looks. Ride is definitely firmer but not uncomfortable, feels much more planted and (what I believe) how it should've been from factory. Ride height definitely went up a little bit, even though I got the B8's which have a shorter shaft.
First picture is Before, second and third are After.

[2014F32435iMsport]

I am thinking of replacing my shocks soon... I have an f32 with m sport suspension. The ride hide definitely increased? If so I may get some mild lowering springs... For me the current height is perfect.

[rhmarquez]

Originally Posted by 2014F32435iMsport

I am thinking of replacing my shocks soon... I have an f32 with m sport suspension. The ride hide definitely increased? If so I may get some mild lowering springs... For me the current height is perfect.

Yeah, wether you get the B6's or the B8's the ride height will increase just a little bit. This is due to the placement of the mounting base on the Bilstein's versus the originals. With the setup I have (B8's and factory M Sport Springs) the height is a little noticeable but doesn't drive me crazy. I'm pretty sure you can pair the Bilstein's with for example H&R Sport Springs and get something closer to your current factory ride height or even a little bit lower.

[Torquey]

I picked up a gently used set of B8s for my F34 xDrive. I am leaning towards pairing these with Eibach mild drop pro-kit springs (06-22), but have wondered about stock M-sport RWD springs as well. Especially since they can be picked up for pretty cheap.

[2014F32435iMsport]

Does anyone know what the OEM replacement would be for the m sport suspension? The Bilstein B4's ? I know everyone complains about how soft the suspension is but I don't really find it an issue on my f32.

[Polo08816]

I re-installed my M Performance Suspension kit a few months ago because I didn't see the point of driving on the Ohlins R&T coilovers during the 6+ months that the car is not going to be on the track.

However, with the MPS kit and F80 front control arms, the front tire rubs on the front portion of the wheel liner when the suspension is fully compressed from potholes, etc.

I'm considering replacing the MPS struts/shocks with the Bilstein B8 struts/shocks in the near future.

Of note, the MPS kit is about 10mm lower than the RWD M Sport suspension.

[strutmonkey1]

Originally Posted by Polo08816

I re-installed my M Performance Suspension kit a few months ago because I didn't see the point of driving on the Ohlins R&T coilovers during the 6+ months that the car is not going to be on the track.

However, with the MPS kit and F80 front control arms, the front tire rubs on the front portion of the wheel liner when the suspension is fully compressed from potholes, etc.

I'm considering replacing the MPS struts/shocks with the Bilstein B8 struts/shocks in the near future.

Of note, the MPS kit is about 10mm lower than the RWD M Sport suspension.

I have the MPerf suspension on my 2015 335i with zero rub. its not the MPerf suspension. B8s will not remedy the rub. Perhaps its the control arms. Do you have stock specs tires/wheels?

[Polo08816]

Originally Posted by strutmonkey1

I have the MPerf suspension on my 2015 335i with zero rub. its not the MPerf suspension. B8s will not remedy the rub. Perhaps its the control arms. Do you have stock specs tires/wheels?

Summer Street
18x8.5 ET38 Apex ARC8
255/40/18 MPS4S

Winter Street
18x8 / 18x8.5 OEM wheels
Front: 235/45/18 MPSAS4
Rear: 245/45/18 MPSAS4

It IS the M3 control arms - you are absolutely right. But it did not rub when I had my Ohlins R&T coilovers. It also did not rub as much when the M3 control arms were new which may indicate how older/worn bushings are allowing some deviation in suspension geometry when quickly compressed.

The slightly oversized tires do not help, however, the increased compression dampening of struts may reduce the frequency of the rubbing.