[wayward.travel]

Let me first start off by apologizing if this information was buried in another thread, but I'd like to get a consensus on which Bilstein Struts I should be considering and the components that should be included in the rebuild/replacement.

Background:
I have a 2015 335i M-Sport with EDC and need to replace my front struts since they're leaking. Since I have 65k miles on the car; I was also going to replace the rear struts as preventative maintenance along with the front lower control arm bushings which have minor cracks.

Front: 235 /40 R18 Non-runflat
Rear: 255 / 40 R18 Runflat

I am in Houston which is known for poor/terrible streets, but I spend a lot of time on the highways which are pretty nice. We also have some stupidly steep driveways which I am always careful about but still scrape on.

Strut Selection:
I've done quite a bit of digging through the forum and I believe I want to replace the OEM EDC Struts with Bilstein B6 to primarily retain the EDC functionality while also retaining a comfortable ride. Bilstein B4 struts seem to be very difficult to find and have seen a few posts that they're back-ordered until March 2022.

Due to the millage on the car, should I consider reusing the springs or would it be recommended to pair Dinan springs which would provide a 3/4" drop. I've read a lot of posts of X-Drive cars opting for ACS springs with B6 Struts, should I be considering these as well? Going with H&R would be too large or a drop and I don't think they're compatible with the B6 struts.

Suspension Replacement:
For the suspension refresh, I am considering replacing all of the rubber insulators, dust guards, and bump stops. I will also replace the upper and lower control arms in the front with TRW components from FCP Euro (KIT-31126855741KT3).

BMW-31336855440 (Front Bump Stops)
BMW-31336787114 (Front Insulator)
BMW-31306791712 (Front Dust Guard)
BMW-33536791538 (Rear Bump Stops)
BMW-33536791709 (Rear Lower Insulator)
BMW-33536764419 (Rear Upper Insulator)

All parts priced out at FCP Euro and BWM South Atlanta for whats listed above including control arms is $530.

Should I also be replacing the top hats (Front & Rear)?

Adding in the B6 Damptronic Struts from BimmerWorld ($1770) and Dinan Performance Spring Set (Part Number D100-0910); costs for the rebuild total $2500.

[Jvac]

Originally Posted by wayward.travel

Let me first start off by apologizing if this information was buried in another thread, but I'd like to get a consensus on which Bilstein Struts I should be considering and the components that should be included in the rebuild/replacement.

Background:
I have a 2015 335i M-Sport with EDC and need to replace my front struts since they're leaking. Since I have 65k miles on the car; I was also going to replace the rear struts as preventative maintenance along with the front lower control arm bushings which have minor cracks.

Front: 235 /40 R18 Non-runflat
Rear: 255 / 40 R18 Runflat

I am in Houston which is known for poor/terrible streets, but I spend a lot of time on the highways which are pretty nice. We also have some stupidly steep driveways which I am always careful about but still scrape on.

Strut Selection:
I've done quite a bit of digging through the forum and I believe I want to replace the OEM EDC Struts with Bilstein B6 to primarily retain the EDC functionality while also retaining a comfortable ride. Bilstein B4 struts seem to be very difficult to find and have seen a few posts that they're back-ordered until March 2022.

Due to the millage on the car, should I consider reusing the springs or would it be recommended to pair Dinan springs which would provide a 3/4" drop. I've read a lot of posts of X-Drive cars opting for ACS springs with B6 Struts, should I be considering these as well? Going with H&R would be too large or a drop and I don't think they're compatible with the B6 struts.

Suspension Replacement:
For the suspension refresh, I am considering replacing all of the rubber insulators, dust guards, and bump stops. I will also replace the upper and lower control arms in the front with TRW components from FCP Euro (KIT-31126855741KT3).

BMW-31336855440 (Front Bump Stops)
BMW-31336787114 (Front Insulator)
BMW-31306791712 (Front Dust Guard)
BMW-33536791538 (Rear Bump Stops)
BMW-33536791709 (Rear Lower Insulator)
BMW-33536764419 (Rear Upper Insulator)

All parts priced out at FCP Euro and BWM South Atlanta for whats listed above including control arms is $530.

Should I also be replacing the top hats (Front & Rear)?

Adding in the B6 Damptronic Struts from BimmerWorld ($1770) and Dinan Performance Spring Set (Part Number D100-0910); costs for the rebuild total $2500.

At 65k with leaking struts, you should go ahead and replace the front strut mounts since they have bearings & rubber that wear. The rears might be ok because I think those are mostly metal and don't hold the springs. They're not too expensive, especially if you buy a suspension refresh kit from Ecs that includes all of them along with a number of bolts that have to be replaced because they are single use.
Also, some of the bilstein front dampers use integrated bump stops, not sure which ones, but make sure with the ones you are buying. If so, then you don't use the oem bump stop along with it.

[cfm56d7b]

B6 Damptronic shocks will provide a much stiffer ride than OEM / B4 Damptronic struts.

Is comfort in daily driving scenarios important? Of course comfort means different things to different drivers ... always good to reconfirm expectations.

[wayward.travel]

Originally Posted by Jvac

At 65k with leaking struts, you should go ahead and replace the front strut mounts since they have bearings & rubber that wear.

Also, some of the Bilstein front dampers use integrated bump stops, not sure which ones, but make sure with the ones you are buying. If so, then you don't use the OEM bump stop along with it.

Thanks Jvac, I found the front strut mounts available at FCP Euro with the washer and bolts. I am also inclined to replace the rear mounts since they're not expensive as you mentioned.

I believe you're correct about the front struts having internal bump stops; although it's been difficult to find confirmation.

cfm56d7b I really like the stiffness of the OEM suspension in sport mode. Even if the B6 struts are slightly stiffer in comfort mode than the current sport mode feeling, I am happy with that. The springs will also accentuate the stiffness of the strut, any feedback from RWD owners with B6 struts would be helpful.

[Orion4]

I got my B4's fm FCP also. I was told by them and Bilstein that B-4's do NOT have internal Bumpstops!! Pls check with them to confirm that for your year/model they do have internal bump stops.

Originally Posted by wayward.travel

Thanks Jvac, I found the front strut mounts available at FCP Euro with the washer and bolts. I am also inclined to replace the rear mounts since they're not expensive as you mentioned.

I believe you're correct about the front struts having internal bump stops; although it's been difficult to find confirmation.

cfm56d7b I really like the stiffness of the OEM suspension in sport mode. Even if the B6 struts are slightly stiffer in comfort mode than the current sport mode feeling, I am happy with that. The springs will also accentuate the stiffness of the strut, any feedback from RWD owners with B6 struts would be helpful.

[gds]

Bilstein B4 /B6 Damptronic are twin tube struts and use external bump stops front and rear so you have to buy new ones or to reuse the old ones( not recommended! )
Bilstein B4 Passive are twin tube struts :they also use external bumpstops front and rear.
Bilstein B6/B8 Passive are monotube struts and have internal bumpstops for the FRONT struts and external bumpstops for the rear.

[cfm56d7b]

Originally Posted by wayward.travel

Thanks Jvac, I found the front strut mounts available at FCP Euro with the washer and bolts. I am also inclined to replace the rear mounts since they're not expensive as you mentioned.

I believe you're correct about the front struts having internal bump stops; although it's been difficult to find confirmation.

cfm56d7b I really like the stiffness of the OEM suspension in sport mode. Even if the B6 struts are slightly stiffer in comfort mode than the current sport mode feeling, I am happy with that. The springs will also accentuate the stiffness of the strut, any feedback from RWD owners with B6 struts would be helpful.

wayward.travel Thanks for sharing more details about preferred suspension behavior. If you are considering lowering springs, please note: B6 Damptronic shocks have been designed to work with OEM springs.

[wayward.travel]

Originally Posted by gdsalepis

Bilstein B4 /B6 Damptronic are twin-tube struts and use external bump stops front and rear so you have to buy new ones or reuse the old ones( not recommended! )

Thanks gdsalepis, really appreciate the confirmation.

cfm56d7b, I've read that B6 struts are intended to be paired with OEM springs; although a modest 20 mm drop should work well with them too. Since I want to retain the EDC functionality, I'm constrained to Bilstein B4, B6, or B16's. As B4's are direct OEM replacements, they also wouldn't be designed for lowering springs. B16's would lower the car too much.

Is there another spring set I should be considering outside Dinan or ACS?

[Jvac]

Originally Posted by wayward.travel

Thanks gdsalepis, really appreciate the confirmation.

cfm56d7b, I've read that B6 struts are intended to be paired with OEM springs; although a modest 20 mm drop should work well with them too. Since I want to retain the EDC functionality, I'm constrained to Bilstein B4, B6, or B16's. As B4's are direct OEM replacements, they also wouldn't be designed for lowering springs. B16's would lower the car too much.

Is there another spring set I should be considering outside Dinan or ACS?

You could also look at eibach or the oem m3/m4 competition springs. Both are progressive springs, not as stiff as dinan or acs, and only lower the car by 10mm over msport ride height. I believe that would still be in the acceptable range of "oem" height and therefore compatible with your chosen dampers. It's worth searching for FaRKle! posts here or on YouTube or contacting him directly to help you pick the right parts. He's done so much legwork on the f series suspension options already and knows just about everything you could want to know about our cars

[wayward.travel]

I've been away for the last few months and am finally home and back looking through the forum to take a decision on refreshing my suspension. To maintain my EDC I don't believe there is anything available outside of Bilstein B4 or B6. I've read great reviews about Koni; although would really prefer to keep the EDC unless there was a very easy and cost-effective way to incorporate non-EDC struts.

From Shock Warehouse; both sets wouldn't be available until mid-April which I can live with. However, before placing the order I'd appreciate some help with spring selection. I originally wanted to get Dinan springs primarily because they were half the price of replacing the original BMW springs while also providing a subtle drop. However, at 30% increase in stiffness over M-Sport Springs, it may be too much for a daily driver. ACS, Eibach, and H&R drop the car too much for Houston driveways and speedbumps. FaRKle! posted a great thread about utilizing F80 springs which could be ideal.

Does anyone know what struts the F80 uses (is it Bilstein B6, B4, or something else)?

[wayward.travel]

I'm considering the following suspension swap since finding either Bilstein B4 or B6 Damptronic Shocks & Struts is impossible. I've read several reviews but am finding most are specific for XDrive; do any RWD cars have experience with the proposed setup?

KONI Special Active 8745-1356 (Front)
KONI Special Active 8245-1357 (Rear)
Dinan D100-0910 (Spring Set)
Full refresh of suspension components (Mounts, hardware, bump stops, insulators, and guards)
Control Arm (Upper & Lower) replacement

TOTAL COST (Parts): $1920

I originally wanted to maintain the EDC functionality but with backorders not improving; I'm forced to bite the bullet. It seems the EDC Delete by coding is easy enough which would be the preferred route given the KW Delete Kit is another ~400 dollars.

[rlesko]

Originally Posted by wayward.travel

I'm considering the following suspension swap since finding either Bilstein B4 or B6 Damptronic Shocks & Struts is impossible. I've read several reviews but am finding most are specific for XDrive; do any RWD cars have experience with the proposed setup?

KONI Special Active 8745-1356 (Front)
KONI Special Active 8245-1357 (Rear)
Dinan D100-0910 (Spring Set)
Full refresh of suspension components (Mounts, hardware, bump stops, insulators, and guards)
Control Arm (Upper & Lower) replacement

TOTAL COST (Parts): $1920

I originally wanted to maintain the EDC functionality but with backorders not improving; I'm forced to bite the bullet. It seems the EDC Delete by coding is easy enough which would be the preferred route given the KW Delete Kit is another ~400 dollars.

Did you end up going with this? Interested in this set up as well