[Ezzer]

Would like for some advice - got my KW Street Comforts installed on my 328i M Sport SDrive (on RFs) a month ago and since early days the front right has had a clonking noise going over medium to large and also sharp bumps. Lately the front left has also started. I’ve completely loss confidence in the car driving over bumps (and the roads here are basically pot hole farms!).

I managed to get some thick 3M sponge tape between the springs as a ghetto test as I noticed the rings having contact marks on them - it seems to have done the trick. However it bugs me that there must be something not right if they are clapping.

Also the car does seem to crash and hit bump stop quite a bit over medium size bumps - which are there A LOT of them here in Bangkok.

My question is - the suspension is installed by reputable shop, car is supposed to be sitting at the highest setting (as I need to clear a lot of speed bumps here) - i am not sure with the KW SCs the highest setting in front is the highest possible per the threads on the damper body or is it a measurement instead? I am afraid the issue may be that the mechanic has run them too high and hence the springs are clapping and subsequently a lot of crashing in the suspension?

As I cannot go lower than this height - perhaps I need the 15mm risers if that’s the issue?

Here are the photos with the shocks loaded and unloaded at the front. (Also showing the spring contact marks and my ghetto repair!)

Thank you!!

[rcaso26]

I had the same issues with KW SC coilovers on my 2015 328i xdrive. Search in the forums and you'll see some of my previous posts with almost the exact issues you're having. I ended up removing them and running an eibach pro kit springs with Koni special active struts and smaller bump stops and the car drives amazing.

[casualDIYer]

There is a max height for the height adjustment collar for both front and rear struts. I wonder if it was exceeded for the front. According to KW for the SC coil overs, from the midpoint where the strut is pinched into the steering knuckle to the bottom of the adjustment collar, that distance cannot exceed 215mm. If this is the case you would be in effect over compressing the spring, limiting its length of travel. This might be possible if KW uses the same shock body with an identical thread count for all car makers but, depending on vehicle, notes min and max heights.

Also, how soft did you set the rebound?

[FaRKle!]

Originally Posted by Ezzer

the front right has had a clonking noise going over medium to large and also sharp bumps. Lately the front left has also started. I’ve completely loss confidence in the car driving over bumps (and the roads here are basically pot hole farms!).

I managed to get some thick 3M sponge tape between the springs as a ghetto test as I noticed the rings having contact marks on them

What you're experiencing is coil bind where the spring is getting fully loaded and all the coils are compressing against each other. Basically this means the spring is bottoming out (fully compressed).

Originally Posted by menncars

There is a max height for the height adjustment collar for both front and rear struts. I wonder if it was exceeded for the front.

This is good advice to check whether the height is set above the max recommended. From the pictures I bet it is.

The reason there's a "max height" is because these springs are relatively soft, and are designed to be used with the bump stops to avoid coil bind. If you set the ride height too high, then the bump stops don't engage soon enough to prevent coil bind. If you like the higher ride height you can install bump stop packers, which are basically shims, to reduce the damper travel required before the bump stops engage.

[Ezzer]

Originally Posted by rcaso26

I had the same issues with KW SC coilovers on my 2015 328i xdrive. Search in the forums and you'll see some of my previous posts with almost the exact issues you're having. I ended up removing them and running an eibach pro kit springs with Koni special active struts and smaller bump stops and the car drives amazing.

Thanks. Indeed read a number of your posts and sorry it didn’t work out. So far I am happy with them except for this (hopefully) one issue. They get quite expensive here in SE Asia so need to stick with them and get through it.

[Ezzer]

Originally Posted by FaRKle!

What you're experiencing is coil bind where the spring is getting fully loaded and all the coils are compressing against each other. Basically this means the spring is bottoming out (fully compressed).


This is good advice to check whether the height is set above the max recommended. From the pictures I bet it is.

The reason there's a "max height" is because these springs are relatively soft, and are designed to be used with the bump stops to avoid coil bind. If you set the ride height too high, then the bump stops don't engage soon enough to prevent coil bind. If you like the higher ride height you can install bump stop packers, which are basically shims, to reduce the damper travel required before the bump stops engage.

Thanks this together with @menncars seems to point to it being too high. Appreciated.

Originally Posted by menncars

There is a max height for the height adjustment collar for both front and rear struts. I wonder if it was exceeded for the front. According to KW for the SC coil overs, from the midpoint where the strut is pinched into the steering knuckle to the bottom of the adjustment collar, that distance cannot exceed 215mm. If this is the case you would be in effect over compressing the spring, limiting its length of travel. This might be possible if KW uses the same shock body with an identical thread count for all car makers but, depending on vehicle, notes min and max heights.

Also, how soft did you set the rebound?

Again thank you, I will look up these parameter and settings and so the mechanic.

The rebound was set at 9 and then moved to 10 open cos it’s too stiff otherwise for road here. I presume the softer it is the more binding issues? Said that I just changed to 11 open on the fronts and it seems to be less “crashy”

[LimboYo]

I had exact same issue with my F32 and I was to get contact with the KW customer service to get a set of replacement spring. Unfortunately, the exact same issue happened again and now I'm looking to replace them with either a set of stiffer springs from KW or from a third party if here is any can fit to the KW SC

[Logicoeur]

Originally Posted by LimboYo

I had exact same issue with my F32 and I was to get contact with the KW customer service to get a set of replacement spring. Unfortunately, the exact same issue happened again and now I'm looking to replace them with either a set of stiffer springs from KW or from a third party if here is any can fit to the KW SC

You didnt read the thread. You have it set too high. It's not the springs

[Ezzer]

Ok so I went to the shop today and got the car jacked up and confirmed the distance between perch and mounting point (point A in KW manual) is 15mm above the KW SC max allowable height.

Definitely saw more binding evidence.

Mechanic wanted to get some custom shims done but I suggested we try and get some original KW spring spacer instead - perhaps the 30mm one.

Would that be the right course of action (to maintain the current height, but lower the perch so it is within the KW 225mm limit (sitting at 240mm) or would that still not make a difference? Or do I need even higher spring spacer? Or... it won’t do anything at all since the spring would still effectively have too limited travel distance if we maitain the same ride height?

As I understand, the spring space for fronts slots in between the perch and the spring, is that right?

Thanks!

[Ezzer]

Really do need some help here as the local indy is non-the-wiser when it comes to these spacers.

Just want to try and understand, if I buy these KW universal spacers (https://www.amazon.com/KW-65030046-U...p/B00I5FQEV6):

1. Do they fit the Street Comfort coilover on the front?
2. Do they (the spacer) fit above the springs (below the top perch/top mount and therefore the recycled rubber perch isolator)
3. Or do the spacers sit above the lower adjustable perch and below the spring?

Given that I have the SCs in front set beyond the allowable max height on the thread and the coils are binding/bottoming out without bumpstop intervention, what I cannot get my head around is if it is scenario 3, then pretty much the spring will still be sitting as it was (the base of the spring would still sit against the spacer at the same height as the original problematic lower perch height) so I can't see how the problem will be solved - the only thing that really moved would be the lower perch into the acceptable max "A" allowable distance but that doesn't mechanically change anything with the spacer in place above it.

if it is scenario 2, then this would make more sense as I will be able to lower the threaded lower perch to the allowable height whilst still achieving my current "beyond-max" ride height.

Thanks a lot in advance - its hard to get help here in Thailand and also searching all over the internet and all I end up finding are photos and threads of spacers which sits on the back spring.

[MacklinUSOB]

To answer your questions above, they will fit between the adjustment collar and the bottom of the spring. I am pretty sure the SC accepts the same 60mm ID springs that my V2s do.

I have heard of the spring spacers but would recommend helper springs instead to mitigate droop effects. You are right to question the effectiveness of either option, though.

You are definitely experiencing coil binding as Farkle explains. I had the same situation with my V2s and ultimately needed to lower the collar until the binding could not occur before bump stop engagement. My kit had different springs obviously but I needed about 1/2" of thread exposed above the collar to stop it. I later upgraded to higher rate Swift Springs to allow more ground clearance, among other reasons. A taller/stiffer spring is the real answer if you are looking for a measurable increase in ride height from where it sits now.

[koreanjesus]

Hey Ezzer did you ever get this sorted? I’m experiencing this exact same issue on my SC’s.

[cfm56d7b]

Joining the discussion. My prior vehicle - F30 335i xDrive - had KW SCs and did not experience any of the reported problems. No additional spacers or any other hardware.

Coil binding can be easily corrected by following KW installation guidelines.

However, if the shock is failing (and it does happen), the weight of the vehicle will compress the spring beyond the intended range causing that metal-over-metal clunking as the coils meet each other.

Suggest to contact KW support.

[koreanjesus]

Thanks for chiming in cfm56d7b

I’m 99% sure my mechanic set the front adjustment collar past the maximum height as instructed per the manual. Have an appointment booked to get it fixed tomorrow morning 🤦‍♂️

Hoping this will fix the “bottoming out” feeling I’ve been getting from uneven road surfaces.

[cfm56d7b]

Originally Posted by koreanjesus

Thanks for chiming in cfm56d7b

I’m 99% sure my mechanic set the front adjustment collar past the maximum height as instructed per the manual. Have an appointment booked to get it fixed tomorrow morning 🤦‍♂️

Hoping this will fix the “bottoming out” feeling I’ve been getting from uneven road surfaces.

Please ask your mechanic to inspect the shocks - just in case.

[koreanjesus]

cfm56d7b Just came back - looks like the fronts were indeed higher than what the KW manual says. Inspected shocks and bump stops and it looked good.

The max height is 8.7” and we settled on 8.5” - driving home I did notice it riding significantly better, I’ll report back after driving around some more later this week.

[cfm56d7b]

Originally Posted by koreanjesus

cfm56d7b Just came back - looks like the fronts were indeed higher than what the KW manual says. Inspected shocks and bump stops and it looked good.

The max height is 8.7” and we settled on 8.5” - driving home I did notice it riding significantly better, I’ll report back after driving around some more later this week.

Very encouraging that the shocks are OK. Hopefully the problem has been resolved.

[jmanB45]

So I had KW Comforts installed earlier this year and have unfortunately run into the same issues as this thread. Basically, the front end bottoming out easily and hard on severe bumps. Rebound is set to the recommended 9 clicks open.

With my front ride height at the desired amount of 1.25" below stock, the spring perch is at the maximum height specified by KW. At this height, the springs are fully compressing before the bump stop engages.
KW advertises a drop of 0.6" to 1.8" but in reality, the car needs to be much lower for the springs to be in the correct window. The springs are just too soft.

I contacted KW, the rep has not been helpful. They're basically saying the coilovers are operating as they should, and I should lower the perch to relieve the springs. When questioned about the height, they say "the way our coilovers work is that automatically the coilover will drop your vehicle from stock 0.6”, from there you can lower the vehicle 1.8” more". Total BS.

I asked for stiffer springs; they won’t replace, but I can buy them. Model #2041 (spring rate 226lbs/in), which comes on their kits for the 6-cylinder cars. Mine are #2039 (spring rate 204lbs/in).

Question: has anyone tried the 2041 springs? Or any other recommendations?

[jmanB45]

Update: So after some back and forth with KW, they have agreed to replace the front and rear springs under warranty.

I found that on the TUV documents, cars with a max front axle load between 1001 to 1090 kg are supposed to use kit 1802000S which has 2041 springs in front, 100-250 rear. KW sold me kit 1802000R which has softer springs 2039 front, 90-250 rear. The dampers are the same in both kits.

The weight plate on my car shows the gross axle front weight as 1020 kg.

I believe this explains why users with 6 cylinder cars have had positive experiences while 4 cylinder cars have had issues bottoming out.

Unfortunately, I will have to pay for a re-install and alignment, KW won't cover that.

[jmanB45]

Replacement springs arrived from KW. Installing these next week, hopefully it solves the issue.

[jmanB45]

Happy to report that the new springs solved the issues. With the fender height set to the same level, the front spring perch is now exactly in the middle of the range specified by KW.

No more bottoming out, the ride feels taut, yet very comfortable over bumps. No more clunking noises, in fact no noises at all.

[cfm56d7b]

Glad you finally solved the problem. KW SC coilovers are still one of the best suspension upgrade options offering a balance between performance and comfort.