[Bob@NC]

I have a 2014 BMW 335i (F30) with the M sport package, which includes the M sport suspension (option code 704).

This suspension has a 10mm drop from the standard (non M sport) suspension.

I’m not sure whether I need the longer B6 or shorter B8 shocks to match with my M sport suspension.

The Bilstein catalog indicates that B8 shocks are correct for cars with the M sport suspension.

But, I also see on the Bilstein.de website FAQ section that B6 shocks can be used with a drop of up to 30mm, and that B8 shocks can be used with a drop of up to 50mm and are optimally used with drops of 30mm to 40mm.

Given this, it would seem to me that the B6 is the correct shock to use with my car, since it only has a 10mm drop.

My preference is to use the B6, since I understand it will be a bit softer/less harsh than the shorter B8.

Does anyone know whether the B6 or the B8 shocks are best for my car’s 10mm drop? I suspect that either one will work, and, if so, what are the pros and cons of each for my application?

Thanks.

[dizzyF30]

B8s are designed to be used with lowering springs. I think you'll be fine with B6s.

[MSportTune2]

Hi! I have the same set up as you and I just replaced the stock MSport absorbers with B6s and used back my stock MSport springs. Best decision I ever made as the problem I had on the MSport suspension particularly the harsh rebound is fix with the B6s!

[Bob@NC]

MSportTune2-

How's the ride on the B6s?

Thanks so much.

[MSportTune2]

I don't have it very long and still playing with tire pressure to fine tune the ride on 19" rims. What happened is old MSport setup is bad i.e., soft and rebound is harsh when hit a dip and when on a fast bank and hits a dip, the tail is unsettled so I compensated by bumping up the tire pressure. Now I am reducing it to get it just right. Feels stiffer than stock for sure but not uncomfortable. It is also more pliant and comfy as it absorbs the road undulations much better.

My comments make sense?

[Bob@NC]

Yes indeed. That sounds perfect. Thanks!

[jebs2k]

i have the b6's lying around from my luxury 328i i traded in
my 335i has msuspension (704) and the ride is much better than the 328
i am still contemplating if i need the b6's in...

[MSportTune2]

F30 front B6 vs stock MSport absorber.
Rear absorbers are similar.

[Bob@NC]

Wow, the front B6s are quite a bit taller than the stock shocks, right? Is the shaft of the stock shock extended all the way up? It looks like it's pushed in and not fully extended.

[Bob@NC]

Here's some interesting info. I called Bilstein, and here's what they told me:

1. I've read on this Board many times that B8s and B6s are valved to have the same stiffness for a given car, and that the only difference between them is their length. This is true sometimes but sometimes not. Bilstein sets the stiffness of the B6 and B8 variants for each car independently, based on what they think is best for that car. So, for some cars B8s are indeed set stiffer, for others B8s have the same stiffness as B6s . In the case of my car, a 2014 335i F30, B6s and B8s have the same stiffness.

2. Here is what they told me are the measurements of B6s and B8s for my car. I'm surprised that the difference in length is quite different for the fronts vs. the rears:

B6 front- 538.5 mm (21.20 in)
B8 front- 518.5 mm (20.41 in)
Difference- 20.0 mm ( .79 in)

B6 rear- 544.5 mm (21.44 in)
B8 rear- 509.5 mm (20.06 in)
Difference- 35.0 mm ( 1.38 in)

3. If you call Bilstein, they can give you this information for your particular car.

[MSportTune2]

Yes Bob. However, after mount and car lowered to the ground, its very slight. I still have 3 fingers height and seem same as my brother in law's msport. I prefer the stock 10mm lowered height as it is good to clear my apartment basement carpark.

[Bob@NC]

Got it. Thanks! As shown in your picture, with the front B6 and the stock front shock sitting beside each other, how much taller is the B6 than the stock shock would you say? And, same question for the rear shocks.

Is the shaft of the stock front shock as show in your picture fully extended, or is in pushed in some?

[MSportTune2]

Hi Bob, the stock shock cannot be extended anymore. We tried when we saw the difference and it would not budged. The difference in height you can see is the stock shock reaches the top of the B6 main shaft. I would say slightly more than an inch.

[MSportTune2]

Rears are exactly the same for both B6 and stock shocks.

Front ride height with B6 on stock springs.

[MSportTune2]

Rear ride height

[Bee Pee]

Originally Posted by MSportTune2

F30 front B6 vs stock MSport absorber.
Rear absorbers are similar.

Bilstein damper shaft looks it has a larger OD than stock - do stock bumpstops still fit Bilsteins ?

[MSportTune2]

Hi Bee Pee, yes, the B6 OD shaft is bigger. Bumpstop wont fit anymore. Installer told me cannot be used and not needed.

[Bob@NC]

I think the monotube design is what makes the shaft wider.

[Bob@NC]

Nice looking car!

[MSportTune2]

Originally Posted by Bob@NC

I think the monotube design is what makes the shaft wider.

Yes. Installer mention that too.

[MSportTune2]

Originally Posted by Bob@NC

Nice looking car!

Thanks. I ended my modding journey with adding the Blistein B6 and the M Performance brakes
this month.

[Bob@NC]

I wonder how it would be to run B8s in front and B6s in the rear? The front B6 is much longer than the stock front shock so a B8 might be better there, but the rear B6 is about the same length as the stock rear shock.