[328iX]

Information regarding F31 specific coilovers / suspension & what I know



Springs & Struts:

ACS springs $320.00 - Bad reverse rake (Previously owned these) For those who aren't aware, they are rebranded Eibach springs - Appear to have been discontinued

RS-R Ti2000 springs $339.00 - No information

H&R springs $248.75 - Too low for stock dampers, it causes a bouncy ride as your strut is effectively too soft to dampen the spring movement. A possibility with Bilstien B8 or B6.

Eibach springs $239.00 - U.S. Website doesn't even list F31, European website lists two springs options (0.8"/0.6") with two variations, one has higher load front springs. I listed the eBay link where I purchased my set Part# E10-20-031-14-22.

Koni special active/ Koni sport struts $686.24, $812.00 - Special active struts seem viable, sport struts good for drops exceeding 1"

Bilstein B4/B6/B8 struts $426.00, $706.02, $776.00 - Good option to use B6/B8 for lowering springs. B4 is an OEM replacement but is OK with ACS/Eibach



Affordable coilovers:

ST coilovers $892.49 - Same as KW V1 minus the coating

Bilstein B14 PSS coilovers $1044.00 - Have heard people who experienced coil binding/chaffing

BC racing coilovers $1050.00 - Not the best quality and poor customer service, is there even f31 x-drive coilovers from them? This is a possible option if you don't mind some drawbacks in quality

Ksport coilovers $935.00 - Never seen anyone try these, personally not a fan of the clamp style attachment for the brake line

CATuned coilovers $1250.00 - Also no info on anyone running these.




Pricier coilovers:

H&R coilovers $1414.95 (Currently running these) They are fairly stiff, not for those seeking comfort. But a solid build with a competitive price point.

Bilstein B16 coilovers $2034.00

Bilstein clubsport coilovers $4208.00

KW V1 coilovers $1444.99 - Coil bind/chaffing? adjusted through preload and not shock body, slammed in the rear (at max height)

KW V2/ KW V3 coilovers - $1827.49 , $2294.99

KW Street comfort coilovers $1886.99

KW DDC coilovers $3459.99

[PKR]

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[cfm56d7b]

I was considering all of the above options when upgrading the suspension on my previous vehicle - 2013 BMW 335i xDrive sedan. After extensive research, KW Street Comfort coilovers became a clear choice. After installation and lowering the suspension slightly, the suspension behavior completely transformed.

[andino]

I wouldn't call V1s slammed the rear but its certainly low. This can be remedied by adding a spring spacer though.

[andino]

To add to your list, there's also ST Coilovers for xdrive now. They're a non-stainless body version of the KW V1s at a much lower price point. They're made by KW and even have the KW stamp on the body. Might be another option if you're interested in V1s and are unwilling to pay the KW V1 price for the compromises.

[328iX]

Originally Posted by andino

To add to your list, there's also ST Coilovers for xdrive now. They're a non-stainless body version of the KW V1s at a much lower price point. They're made by KW and even have the KW stamp on the body. Might be another option if you're interested in V1s and are unwilling to pay the KW V1 price for the compromises.

Originally Posted by andino

I wouldn't call V1s slammed the rear but its certainly low. This can be remedied by adding a spring spacer though.

It can be remedied by spacers but doesn't solve the binding and preload adjustment upfront.

Also I was under the impression ST had nothing for xdrive but I'll look into it now

[andino]

Originally Posted by 328dX

It can be remedied by spacers but doesn't solve the binding and preload adjustment upfront.

Also I was under the impression ST had nothing for xdrive but I'll look into it now

Right it won't solve the binding unfortunately but its not too bad tbh. Its a bit annoying but I think the majority of the noise will go away after I get my adjustable endlinks in. Right now, I suspect my sway it impacting my control arm and causing a clunking.

I saw the other day in another suspension thread (something like ST vs KW). They mentioned they have ordered STs for xdrive at the end of the thread. I would inquire about f30 or f36 coils if they don't have them for f31. KW ships the same PN for f31/f36 so might be a good place to start. And Bilstein uses the same PN across of f3x so they're all pretty compatible with each other. The main thing is the xdrive strut and i suppose the spring height for the front springs to account for different motors.

[328iX]

Originally Posted by andino

Right it won't solve the binding unfortunately but its not too bad tbh. Its a bit annoying but I think the majority of the noise will go away after I get my adjustable endlinks in. Right now, I suspect my sway it impacting my control arm and causing a clunking.

I saw the other day in another suspension thread (something like ST vs KW). They mentioned they have ordered STs for xdrive at the end of the thread. I would inquire about f30 or f36 coils if they don't have them for f31. KW ships the same PN for f31/f36 so might be a good place to start. And Bilstein uses the same PN across of f3x so they're all pretty compatible with each other. The main thing is the xdrive strut and i suppose the spring height for the front springs to account for different motors.

I've heard the front is the same? it's the rear that needs to account for the wagon weight in the rear and height is taller? IDK everything is so vague and just speculation.

All i want is moderate lowering 25-30mm and no reverse rake. Also no stupid problems like the coils rubbing!

[andino]

You can compensate for the height since the coils are adjustable height. Its not like static springs in that regard where that have to accommodate the weight before the drop.

[FaRKle!]

Originally Posted by 328dX

Eibach - Website is horrible. I only see springs that offer 0.8/0.6" drop but can't find any forum posts of people running these, website doesn't show sportline springs being available?

I'm pretty sure if you look through my posting history you'll find plenty on Eibach F31 springs (especially since that's what I run). Use the Euro site. Much better documentation and catalogging.

[328iX]

Originally Posted by FaRKle!

I'm pretty sure if you look through my posting history you'll find plenty on Eibach F31 springs (especially since that's what I run). Use the Euro site. Much better documentation and catalogging.

Your posts are really not helpful without references/links/part numbers

Eibachs U.S website doesn't even list a 328d, so I input the 328xi wagon, one set of springs come up HERE

Their European website shows a different set of springs, they do show selection for the 320d x-drive (same as U.S. 328d) HERE

Unless I’m missing something or you can show me if they have another website I’m not finding, (and shows definite compatibility) I’d be glad to purchase

[FaRKle!]

Originally Posted by 328dX

Your posts are really not helpful without references/links/part numbers

Eibachs U.S website doesn't even list a 328d, so I input the 328xi wagon, one set of springs come up HERE

Their European website shows a different set of springs, they do show selection for the 320d x-drive (same as U.S. 328d) HERE

Unless I’m missing something or you can show me if they have another website I’m not finding, (and shows definite compatibility) I’d be glad to purchase

Just last week I posted a TON of Eibach reference data including F31 328i/328d/320d specific spring PNs and specs (the ones I originally purchased) in a thread that you started! If you can't navigate the Eibach Euro catalog and compare specs with all that, then I don't know what to say... Their USA site is useless in comparison and a joke at best.

If you look at the difference in the kits listed between the USA and Euro sites for the 4-cyl F31 you'll see the USA site lists the old kit PN while the Euro site has their latest/current recommendation. If you look at the documentation you'll see what the main difference is between the rear springs in those two kits.

Not a single one of the options you listed in your initial post in this thread has as much reference/spec/test data out there as the Eibach documentation I've posted.

[328iX]

Originally Posted by FaRKle!

Just last week I posted a TON of Eibach reference data including F31 328i/328d/320d specific spring PNs and specs (the ones I originally purchased) in a thread that you started! If you can't navigate the Eibach Euro catalog and compare specs with all that, then I don't know what to say... Their USA site is useless in comparison and a joke at best.

Not a single one of the options you listed in your initial post in this thread has as much reference/spec/test data out there as the Eibach documentation I've posted.

Ok, you said you believe ACS springs are made by Eibach as the TUV data is the same.

I don't see part numbers
That was referencing ACS not eibach
I said I'm aware of the 0.6/0.8" springs from eibach.
Still doesn't answer my question about sportline springs and who's running them. I have no idea what you're running I read a lot of posts on here from everyone.

I showed you what I see from the Euro website. Still only shows sport springs and the B12 kit, which I can't even find for sale here in the U.S or can confirm compatibility by someone running them

[FaRKle!]

Originally Posted by 328dX

Ok, you said you believe ACS springs are made by Eibach as the TUV data is the same.

I don't see part numbers
That was referencing ACS not eibach
I said I'm aware of the 0.6/0.8" springs from eibach.
Still doesn't answer my question about sportline springs and who's running them. I have no idea what you're running I read a lot of posts on here from everyone.

I showed you what I see from the Euro website. Still only shows sport springs and the B12 kit, which I can't even find for sale here in the U.S or can confirm compatibility by someone running them

You're blind. Read ALL my posts in that thread you started. There are LOTS of links to reference documentation, PNs listed of the springs I'm using, ect.

*hint* if a string of words in my posts are underlined, they have a link.

[328iX]

Originally Posted by FaRKle!

You're blind. Read ALL my posts in that thread you started. There are LOTS of links to reference documentation, PNs listed of the springs I'm using, ect.

*hint* if a string of words in my posts are underlined, they have a link.

Ok I found it so you're running a combination of springs from eibach. How does your car sit. And what dampers. I'm on my phone it was hard for me to find it.

[sspade]

I think youll be happy once you install the B8. The reverse rake isn't as pronounced on the sedan with ACS springs, especially with B8.

Maybe your rear dampers are sagging a bit and are tired. Truth be told... I installed my B8 rears separate from front because fronts were on back order. Rears alone will improve ride, fronts will be the icing.

[andino]

Originally Posted by 328dX

Ok I found it so you're running a combination of springs from eibach. How does your car sit. And what dampers. I'm on my phone it was hard for me to find it.

Check out his build thread. It has all the photos you're looking for along with his setup.

Suspension on f3x is universal across all models essentially. It's just varying spring rates and such for different motors/body styles but they'll all fit. Wagons carry about 60-80lbs extra weight over the rear wheels iirc. You can pretty much use f36 parts as well since they also carry extra weight.

[328iX]

Originally Posted by andino

Check out his build thread. It has all the photos you're looking for along with his setup.

Suspension on f3x is universal across all models essentially. It's just varying spring rates and such for different motors/body styles but they'll all fit. Wagons carry about 60-80lbs extra weight over the rear wheels iirc. You can pretty much use f36 parts as well since they also carry extra weight.

I've seen pictures of his car I believe but doesn't answer the technical aspect. FaRKle! are you on stock dampers? Thank you

[FaRKle!]

Originally Posted by 328dX

I've seen pictures of his car I believe but doesn't answer the technical aspect. FaRKle! are you on stock dampers? Thank you

Quoted from your thread from last week :

Originally Posted by FaRKle!

I've had Eibach springs on my adaptive damper car for a year and ~20k miles. This is with plenty of track days and also dirt/gravel/trail road driving. No issues with the dampers. In fact I just dynoed the adaptive dampers yesterday and they're able to put out lots of compression/rebound force, on par or greater than aftermarket dampers like the Bilstein B6. That said, BMW's EDC profile/programming doesn't let them do those max rates, but the dampers are physically capable of it.

[328iX]

Originally Posted by FaRKle!

Quoted from your thread from last week :

Ok thanks smart ass haha I can't remember every post out there lol.

This only resolves one suspension solution (eibach) tho lol.

Did they allow you to buy front or rear springs only? Or did you have to buy both kits

[328iX]

Originally Posted by sspade

I think youll be happy once you install the B8. The reverse rake isn't as pronounced on the sedan with ACS springs, especially with B8.

Maybe your rear dampers are sagging a bit and are tired. Truth be told... I installed my B8 rears separate from front because fronts were on back order. Rears alone will improve ride, fronts will be the icing.

I don't think my struts are causing any difference in ride height, but i'd be willing to see the gaps other people have.

Here is my current gaps with ACS springs on stock dampers: 4.52" front (lip of the wheel to arch of the fender) and 3.82" rear. If anyone else has an F31 i'd really like to know what theirs is.

Also, my heights match left and right sides, so both rears are at the same height, and both fronts are at the same height.

[andino]

Originally Posted by 328dX

Ok thanks smart ass haha I can't remember every post out there lol.

This only resolves one suspension solution (eibach) tho lol.

Did they allow you to buy front or rear springs only? Or did you have to buy both kits

He's been mixing and matching kits iirc. His setup is pretty epic now though. Can't wait to hear how it performs at the track.