[oregondonor]

It seems like finding the best combination of OE damper, off the shelf springs, combined with the appropriate bump stops is near impossible without major trial and error.

There is so much misinformation on forums from car owners that really don't know much about suspension theory as well as the possibility that manufactures of aftermarket springs don't really care to instill knowledge into their customers.

As I approach the end of my warranty of my 2016 435i ZHP I have started my research on aftermarket suspension components. In an effort to maintain some kind of fiscal responsibility I want to start with a spring set and matching bump stops. I would also love to get at least a one inch drop all around. Seems easy right? Not so much!

The knowns are front and rear bump stop height and probably front and rear spring rate (I say probably as I am unsure at this point if the OE rates are publicly known).

The unknowns are the damping characteristics of the OE dampers. I have the adaptive dampers and for all I know BMW is working some magic to cancel out a pitchy OE setup.

Lets say I don't care about driving towards a perfectly flat ride and just want to get a set of springs that gets my car to the ride height I want? I still need to find bump stops that will allow proper travel.

Looking at the BMW OE parts catalog it appears I am running this combination of stops:

Front 31-33-6-860-160
Rear 33-53-6-858-240

From the research I have done these appear to be pretty short already and I feel are working good on my OE setup. Looks to be the same part as the F82. Any aftermarket spring will require me to install something shorter in order to not sit on the stops at static ride height. I suppose I could cut the stop as I have done in the past but I am trying to avoid this as there "is" substantial engineering in these small foamy things.

I may just have to find a OE setup that has a closely matching spring rate of say H&R Super Sport springs and use those bump stops? Cutting one inch off of a bump stop that is only 2.5 inches long seems extreme?

Another option is to find an aftermarket bump stop.

[Eschmacher]

Have you read through this thread?
https://f30.bimmerpost.com/forums/sh....php?t=1621134

I found it informative.

[FaRKle!]

Originally Posted by oregondonor

Front 31-33-6-860-160
Rear 33-53-6-858-240

From the research I have done these appear to be pretty short already and I feel are working good on my OE setup. Looks to be the same part as the F82.

These aren't the same as on the F80/82. RealOEM shows what other models use the same front and rear bump stops are used on.

[Jvac]

I'm in the same boat as you. Trying to sift through a mountain of subjective forum reviews, vague marketing claims and confusing or conflicting information. My '15 335 w/m-sport (w/adaptive dampers) is nearing the end of the warranty too and I am trying to sort out the right move without making a costly mistake. I have only 23k miles on the adaptive dampers and given their high price, I'd rather work with them then ditch them for now. It also doesn't seem like there is much chance of resale as most of the forum guys go with coilovers or aftermarket shocks & springs, leaving a 2000$ set of dampers to collect dust in the garage. Just seems irresponsible to me to ditch them before they're worn out.
First I thought that Dinan springs& bump stops was the way to go, but I believe they are 30% stiffer than oe, and they are linear. This leads me to believe that they'd be too harsh for daily driving and the roads where I live are not too good.
I started looking at the eibach pro kit which are maybe 15% stiffer, but in a progressive manner. Sounds like they might be better suited for daily use but I can't work out how they say they lower my car by another. 75 inch but reuse the oe bump stops. It sounds to me like you'd be hitting said bump stops a lot more often so shorter stops would be in order. But I am new to this type of tuning and would be taking an uninformed stab at the right combo from there.
Finally, it seems like most of the coilover kits are a) way more expensive, b) overly stiff for a daily, and c) lower the car a bit too much for my taste.
My goal is to strike a mix of performance and comfort that is good overall without being too aggressive toward any one extreme.
In the end I may pay to solicit Farkle's advice, as he has done extensive testing on the 3 series and appears better informed than most. It'd probably take me years to get to his level on my own.

[FaRKle!]

Originally Posted by Jvac

First I thought that Dinan springs& bump stops was the way to go, but I believe they are 30% stiffer than oe, and they are linear. This leads me to believe that they'd be too harsh for daily driving and the roads where I live are not too good.
I started looking at the eibach pro kit which are maybe 15% stiffer, but in a progressive manner. Sounds like they might be better suited for daily use but I can't work out how they say they lower my car by another. 75 inch but reuse the oe bump stops.

Harshness has a lot to do with the dampers.

Eibach Pro-kit and Dinan springs are both linear (even though some marketing materials may say progressive for the Eibach Pro-kit).

I'm typically able to find lowering solutions that maintain OE spring rates.

[oregondonor]

Originally Posted by FaRKle!

These aren't the same as on the F80/82. RealOEM shows what other models use the same front and rear bump stops are used on.

So it looks like the F82 OE bump stops are:

Front - 31336859768
Rear - 31337847662

@Andrew - It still looks like my initial part numbers that I have listed for the bump stops in my car with EDC is correct. So the question is what are the dimensions? Guess I'll run down to parts and take some measurements. Unless you have that information handy?

[cfm56d7b]

Is your budget limited to springs only?

Are you interested in retaining OEM M Adaptive suspension?

[oregondonor]

Originally Posted by cfm56d7b

Is your budget limited to springs only?

Are you interested in retaining OEM M Adaptive suspension?

It's more about retaining the adaptive suspension then budget. But being fiscally responsible is a factor as well.

I feel my solution would be much easier if I was to just code out the EDC and get fully adjustable coilovers. A set of Ohlins and call it good!

[Jvac]

Originally Posted by oregondonor

It's more about retaining the adaptive suspension then budget. But being fiscally responsible is a factor as well.

I feel my solution would be much easier if I was to just code out the EDC and get fully adjustable coilovers. A set of Ohlins and call it good!

Kw makes coilover sets that are compatible with the adaptive suspension for about 200$ more than the non-adaptive sets. The v3 setup is about the same price as the ohlins and offers fully adjustable ride height, rebound and compression. Wonder if they are any good. Alternatively, the adaptive function is easily coded out according to some threads on this forum, which opens up a wider variety of suspension options. But I'm like you, I hate the idea of ditching the oe functionality and perfectly serviceable parts of its not totally necessary.

[FaRKle!]

Originally Posted by oregondonor

I feel my solution would be much easier if I was to just code out the EDC and get fully adjustable coilovers. A set of Ohlins and call it good!

Why not? I coded EDC out and don't miss it.

Originally Posted by Jvac

Alternatively, the adaptive function is easily coded out according to some threads on this forum, which opens up a wider variety of suspension options. But I'm like you, I hate the idea of ditching the oe functionality and perfectly serviceable parts of its not totally necessary.

Once you realize that even the EDC with whatever springs you want won't give you optimal dampening, you won't feel so bad ditching it .

[oregondonor]

Originally Posted by FaRKle!

Why not? I coded EDC out and don't miss it.

Once you realize that even the EDC with whatever springs you want won't give you optimal dampening, you won't feel so bad ditching it .

How long was it before you coded out EDC?

I guess I'm like a dog on a bone...I want to get a great setup with OE dampers. I feel so many people are doing it wrong with most owners sitting on their bump stops and they don't even know it.

Maybe Fat Cat Motorsports can hook me up with some custom bump stops?

[Jvac]

Originally Posted by FaRKle!

Why not? I coded EDC out and don't miss it.



Once you realize that even the EDC with whatever springs you want won't give you optimal dampening, you won't feel so bad ditching it .

I'm sure you're right, I'm just stubborn. I'm Hoping there's a way to get a good enough setup without totally overhauling my suspension and the big financial investment that goes along with that, but if optimum performance is achievable, it's worth the extra money in the long run.

[johnung]

Originally Posted by oregondonor

It seems like finding the best combination of OE damper, off the shelf springs, combined with the appropriate bump stops is near impossible without major trial and error.

There is so much misinformation on forums from car owners that really don't know much about suspension theory as well as the possibility that manufactures of aftermarket springs don't really care to instill knowledge into their customers.

As I approach the end of my warranty of my 2016 435i ZHP I have started my research on aftermarket suspension components. In an effort to maintain some kind of fiscal responsibility I want to start with a spring set and matching bump stops. I would also love to get at least a one inch drop all around. Seems easy right? Not so much!

The knowns are front and rear bump stop height and probably front and rear spring rate (I say probably as I am unsure at this point if the OE rates are publicly known).

The unknowns are the damping characteristics of the OE dampers. I have the adaptive dampers and for all I know BMW is working some magic to cancel out a pitchy OE setup.

Lets say I don't care about driving towards a perfectly flat ride and just want to get a set of springs that gets my car to the ride height I want? I still need to find bump stops that will allow proper travel.

Looking at the BMW OE parts catalog it appears I am running this combination of stops:

Front 31-33-6-860-160
Rear 33-53-6-858-240

From the research I have done these appear to be pretty short already and I feel are working good on my OE setup. Looks to be the same part as the F82. Any aftermarket spring will require me to install something shorter in order to not sit on the stops at static ride height. I suppose I could cut the stop as I have done in the past but I am trying to avoid this as there "is" substantial engineering in these small foamy things.

I may just have to find a OE setup that has a closely matching spring rate of say H&R Super Sport springs and use those bump stops? Cutting one inch off of a bump stop that is only 2.5 inches long seems extreme?

Another option is to find an aftermarket bump stop.

Just my two cents, for what it's worth...

From listening to what you've said, my suggestion would be to keep the adaptive dampers. I've read a lot of people with adaptive who have gone with Eibach springs and are very happy with the drop and the ride. The Eibachs are slightly stiffer than stock but not so much to be a dramatic departure.

Eibach tests their springs with the stock dampers. I'd call their tech support to ask your bump stop questions.

I have a different chassis and suspension than you do, but I was also pretty concerned about bump stops when I was deciding on my eventual Koni/Eibach solution. I had some excellent conversations with Koni tech support. They assured me that they had tested my chassis with their dampers and the exact Eibach springs that I was considering. Their engineers determined that the stock bump stops were fine. They double checked the calculations and assured me that if that wasn't the case they would provide me with instructions on how to modify my stops or provide a new bump stop if it were necessary.

Again, based on your statements, the next step might be to try the Eibach springs for about $300, see how/if they meet your goals. If they don't, then sell them and move on to one of the more expensive solutions that has been discussed.

[FaRKle!]

Originally Posted by oregondonor

How long was it before you coded out EDC?

I guess I'm like a dog on a bone...I want to get a great setup with OE dampers. I feel so many people are doing it wrong with most owners sitting on their bump stops and they don't even know it.

Maybe Fat Cat Motorsports can hook me up with some custom bump stops?

I kept the stock EDC dampers a bit more than 2yrs before deciding I'd gone as far as I could with them and moving to Fat Cat's bespoke passive dampers. EDC was fine for the street, but couldn't keep up with the track.

FCM might be able to make a custom bump stop recommendation, but it won't likely fit into the top mounts, which doesn't matter a whole lot.

Originally Posted by Jvac

I'm sure you're right, I'm just stubborn. I'm Hoping there's a way to get a good enough setup without totally overhauling my suspension and the big financial investment that goes along with that, but if optimum performance is achievable, it's worth the extra money in the long run.

You can likely get "good enough" with just springs and dinan shockware for daily driving or fun backroads. The deficiency shows when really pushing it though (like on the track or AutoX).

[cfm56d7b]

Originally Posted by Jvac

Kw makes coilover sets that are compatible with the adaptive suspension for about 200$ more than the non-adaptive sets. The v3 setup is about the same price as the ohlins and offers fully adjustable ride height, rebound and compression. Wonder if they are any good. Alternatively, the adaptive function is easily coded out according to some threads on this forum, which opens up a wider variety of suspension options. But I'm like you, I hate the idea of ditching the oe functionality and perfectly serviceable parts of its not totally necessary.

The minimum lowering with KW V3 coilovers is a bit too low for me. I wish KW V3 offered lowering range from OEM height to something lower. Otherwise, KW V3 is a great product. Ohlins R&T coilovers are perhaps one of the best coilovers at the moment.

[Jvac]

Originally Posted by cfm56d7b

The minimum lowering with KW V3 coilovers is a bit too low for me. I wish KW V3 offered lowering range from OEM height to something lower. Otherwise, KW V3 is a great product. Ohlins R&T coilovers are perhaps one of the best coilovers at the moment.

Looks to me like the minimum drop is ~1" from stock on both the kw and the ohlins. Am I reading that wrong?

[Jvac]

Originally Posted by FaRKle!

I kept the stock EDC dampers a bit more than 2yrs before deciding I'd gone as far as I could with them and moving to Fat Cat's bespoke passive dampers. EDC was fine for the street, but couldn't keep up with the track.

FCM might be able to make a custom bump stop recommendation, but it won't likely fit into the top mounts, which doesn't matter a whole lot.




You can likely get "good enough" with just springs and dinan shockware for daily driving or fun backroads. The deficiency shows when really pushing it though (like on the track or AutoX).

It has always been my goal to get the car on the track, but it probably won't happen as soon or often as I'd like. And I don't want to over-tune the car for occasional track duty at the expense of daily driver duty. But even the springs/bump stops/shockware is going to be nearly $1000 including the labor. At that point, might as well go all the way and get the good stuff.

[cfm56d7b]

Originally Posted by Jvac

Looks to me like the minimum drop is ~1" from stock on both the kw and the ohlins. Am I reading that wrong?

Ohlins R&T coilovers can be set at OEM height if the original suspension was M Sport suspension (non adaptive).

https://f30.bimmerpost.com/forums/sh...ins+oem+height

[Jvac]

Originally Posted by cfm56d7b

Ohlins R&T coilovers can be set at OEM height if the original suspension was M Sport suspension (non adaptive).

https://f30.bimmerpost.com/forums/sh...ins+oem+height

Thanks for the info. Reading further in that thread where the guy said he'd been waiting 4 months for replacement parts from ohlins is pretty unacceptable though. I expect the manufacturer of high end goods to provide high end service and support as well. 4 months for critical vehicle parts is ridiculous to me.

[cfm56d7b]

Originally Posted by Jvac

Thanks for the info. Reading further in that thread where the guy said he'd been waiting 4 months for replacement parts from ohlins is pretty unacceptable though. I expect the manufacturer of high end goods to provide high end service and support as well. 4 months for critical vehicle parts is ridiculous to me.

Waiting for 4 months is a bit unusual. Could be a supplier related problem.

[xpro]

As anything with suspension is trail and error, you either listen to people that have tried and tested or you can come up with your own decision.

Changing the suspension will come with pros and cons no doubt.

You either want it harsh and sporty, or purely for looks. Theres lots to choose.

I have a 335xd and I also wanted to get rid of that shocking OE suspension.

Went with Bilstein B8 dampers and -05 springs. Car looked ace, but way too low, scraping every bit of uneven ground I could find.. Looking at that nice splitter you have, hmm that wouldn't last long. Take that in consideration. Potholes and bumps on the road just destroy them

OE Bumps stops were not an issue, as there was still some play left unless you were heavy loaded and going over massive road undulations.

Then I tried different set up as mr Farkle suggested, as I wanted something more driveable and possibly a bit stiffer.
Changed to a higher loading springs and some 10mm higher. Eibach -06

That completely transformed my car. Its still low but not low rider low.. but the drive is great now.

[dsc888]

Originally Posted by xpro

Then I tried different set up as mr Farkle suggested, as I wanted something more driveable and possibly a bit stiffer.
Changed to a higher loading springs and some 10mm higher. Eibach -06

That completely transformed my car. Its still low but not low rider low.. but the drive is great now.

Oh wow! You ended up back to the Eibach recommended -06 springs. Is the ride still about the same firmness with better suspension travel so as to not bottom out on deeper bumps? That is the only issues I have right now on secondary roads where there's been a lot of construction work where the undulations from road work can sometimes cause the front suspension to hit the bump stops unless I am below 20 MPH. The -06 springs should have netted you another 15mm of shock travel.

I will ride on my -05 springs for at least another year before I decide to switch or not. The towns around where I live have started a huge road repaving project so I might be good for a while as the lower springs does help in cornering and lowering the COG of the car.