Solution for KW Clubsport Inner Wheel Clearance Issues

[Kelse92]

Originally Posted by mikejnc

Anyone run 275/35/18 tires on 18x10.5 with the shorter Eibach springs with success?

Yes, fits fine

[mikejnc]

Originally Posted by Kelse92

Yes, fits fine

Thanks! What final offset are you running on the wheels to avoid perch rub?

[Kelse92]

Originally Posted by mikejnc

Thanks! What final offset are you running on the wheels to avoid perch rub?

Et22 or 25 works well. I have the et27 EC-7’s I run with a 5mm spacer

[LS3Series]

Some pics for visual reference.

2006 E90 330i converted to complete M3 front suspension brakes etc.

KW CS 2ways (M3 version)

Apex Arc8 18x10 et 25

Bridgestone RE71R 275/35/18 Tires

KW stock 170/61/110 yellow spring, Pictured with 5mm spacer! Wouldnt fit without spacer.

Eibach 140/60/110 red spring, pictured NO spacer.

For reference, my spring perch is moved up Exactly 30mm higher for the eibach spring which is the same as the difference in springs and equal ride height as a result.

For the KW spring the spring perch is 10 turns up from bottom, Eibach spring I am 8.5 Turns down from the top.

Dead Horse I know, but maybe another visual will help someone else!

[Iceberg157]

I have KW CS 3-ways. Will the same Eibach spring work (140/60/110)?

[slicer]

Originally Posted by Iceberg157

I have KW CS 3-ways. Will the same Eibach spring work (140/60/110)?

Yes, but check your spring rate to ensure it's what is on the car unless you are looking to change the spring rate. Some kits came with 90 nm, some with 110 nm.

[Iceberg157]

Originally Posted by slicer

Yes, but check your spring rate to ensure it's what is on the car unless you are looking to change the spring rate. Some kits came with 90 nm, some with 110 nm.

Just looked and the spring shows 110-170*. Im assuming its 110nm then. I want to keep the same spring rate so it would be that same part #?

[slicer]

Originally Posted by Iceberg157

Just looked and the spring shows 110-170*. Im assuming its 110nm then. I want to keep the same spring rate so it would be that same part #?

Yes

[Iceberg157]

Originally Posted by slicer

Yes

Thanks for confirming.

[Kelse92]

I pulled my clubsports off a few weeks ago and had KW rebuild them. About to put them back on but it's got me thinking again... At the ride height I was at when I pulled them off the helper spring was fully compressed and really only acting as a 'spacer,' even at full-droop so any con's of just ditching the helper and getting a 160/170 length spring?

[tsk94]

Originally Posted by Kelse92

I pulled my clubsports off a few weeks ago and had KW rebuild them. About to put them back on but it's got me thinking again... At the ride height I was at when I pulled them off the helper spring was fully compressed and really only acting as a 'spacer,' even at full-droop so any con's of just ditching the helper and getting a 160/170 length spring?

Your helper was fully compressed at FULL droop?

If that's the case, then the helper is doing nothing. Like you said, it's just acting as a spacer and taking up space.

[Kelse92]

Originally Posted by tsk94

Your helper was fully compressed at FULL droop?

If that's the case, then the helper is doing nothing. Like you said, it's just acting as a spacer and taking up space.

Yup, I forgot to take a picture but it was dong nothing. I think the small Eibach spring though will be just a bit too short without it though so going to see if I can dig up the OE KW Springs or get some new ones.

[tsk94]

Originally Posted by Kelse92

Yup, I forgot to take a picture but it was dong nothing. I think the small Eibach spring though will be just a bit too short without it though so going to see if I can dig up the OE KW Springs or get some new ones.

You must have the car quite high haha. If that's the ride height you're going to stay at though, there's no reason you need to keep it there. With that being said, the only reason to go through the hassle of taking it off would be if you need additional clearance for a larger tire.

KW should be able to get you any spring length and rate you want, but there seems to be some good Eibach options people have tested - not sure if they'd work for your ride height though. Going to a shorter spring, in the same rate, is fine as long as the spring has sufficient stroke. Going stiffer is much simpler because you'll need less stroke, thus a shorter and stiffer spring is an easier replacement. With that being said, I wouldn't recommend going stiffer in the front without stiffening the rear, the CS (and 99% of all suspension options for the E9X M3's for that matter) are already very front-biased.

[Kelse92]

Originally Posted by tsk94

You must have the car quite high haha. If that's the ride height you're going to stay at though, there's no reason you need to keep it there. With that being said, the only reason to go through the hassle of taking it off would be if you need additional clearance for a larger tire.

KW should be able to get you any spring length and rate you want, but there seems to be some good Eibach options people have tested - not sure if they'd work for your ride height though. Going to a shorter spring, in the same rate, is fine as long as the spring has sufficient stroke. Going stiffer is much simpler because you'll need less stroke, thus a shorter and stiffer spring is an easier replacement. With that being said, I wouldn't recommend going stiffer in the front without stiffening the rear, the CS (and 99% of all suspension options for the E9X M3's for that matter) are already very front-biased.

Yeah, I like the shorter Eibach spring I have now, it's just going to be too short without the helper. For reference on my ride height, I have it up there, but its still a little lower than stock. My spring perch is pretty close to the top of the shock threads though up front. Trying to cram the biggest tire I possibly can under the car

[tsk94]

Originally Posted by Kelse92

Yeah, I like the shorter Eibach spring I have now, it's just going to be too short without the helper. For reference on my ride height, I have it up there, but its still a little lower than stock. My spring perch is pretty close to the top of the shock threads though up front. Trying to cram the biggest tire I possibly can under the car

So, you're already running a shorter Eibach spring? If that's the case and you're worried that removing the helper will simply be too much, you can look into doing something similar to what I did on my KW's. Is the rate and length of your helper marked on the spring? I believe it should be a 10-60-80, 10n/mm is the rate, and 80mm is the height. That's what mine originally were and I believe the CS uses the same.. I went to a 3-60-80 helper, which is the same length, but a softer rate. Due to being a softer rate the compressed height of the spring was something like 12mm less. This might be an option for you. I went into it in more detail in my build thread if you're interested.

[slicer]

Originally Posted by Kelse92

Yup, I forgot to take a picture but it was dong nothing. I think the small Eibach spring though will be just a bit too short without it though so going to see if I can dig up the OE KW Springs or get some new ones.

You need both front wheels off the ground to test. The swaybar is compressing your helper with only one wheel off ground. Helper spring prevents miss alignment if BOTH front wheels are unweighted.

[Kelse92]

Originally Posted by slicer

You need both front wheels off the ground to test. The swaybar is compressing your helper with only one wheel off ground. Helper spring prevents miss alignment if BOTH front wheels are unweighted.

I had the car on a lift when I looked at this.

[Kelse92]

Originally Posted by tsk94

So, you're already running a shorter Eibach spring? If that's the case and you're worried that removing the helper will simply be too much, you can look into doing something similar to what I did on my KW's. Is the rate and length of your helper marked on the spring? I believe it should be a 10-60-80, 10n/mm is the rate, and 80mm is the height. That's what mine originally were and I believe the CS uses the same.. I went to a 3-60-80 helper, which is the same length, but a softer rate. Due to being a softer rate the compressed height of the spring was something like 12mm less. This might be an option for you. I went into it in more detail in my build thread if you're interested.

Thanks, that's a good idea on the lighter helper. Might be a good happy medium here. I don't totally want to ditch the helper, but the 10-68-80 one is too much. I'll take a look over in your thread

[slicer]

Originally Posted by Kelse92

I had the car on a lift when I looked at this.

Cool.

[malem]

Originally Posted by slicer

Also note that KW changed their spring rates on the CS kits subsequent to this thread. New KW CS kits come with 110nm front springs.

Do we have any feedback between the 90nm vs 110nm springs in regads to ride quality / usage? I recently purchased some KW CS 2 ways for a dedicated track setup, I am running a 275/35/18 - 18x10.5 +25 square setup. Based on this thread I believe I am going to need to order some of the eibach springs to clear my wheel setup.

My question is as a track focused setup is the 90nm springs or the 110nm springs preferred?

Does the stock KW CS helper spring work with the shorter eibach springs? Or are you ordering a different sized helper from KW.

[slicer]

Originally Posted by malem

Do we have any feedback between the 90nm vs 110nm springs in regads to ride quality / usage? I recently purchased some KW CS 2 ways for a dedicated track setup, I am running a 275/35/18 - 18x10.5 +25 square setup. Based on this thread I believe I am going to need to order some of the eibach springs to clear my wheel setup.

My question is as a track focused setup is the 90nm springs or the 110nm springs preferred?

Does the stock KW CS helper spring work with the shorter eibach springs? Or are you ordering a different sized helper from KW.

The helper is compatible. I specifically discussed keeping the helper in place early in this thread.

90 vs 110 is harder to answer. I think there are varying approaches/perspectives on spring rate. It is worth noting that it's unknown whether the updated version of the kit has different shock valving to match the stiffer springs.

[//steve\\]

Originally Posted by slicer

The helper is compatible. I specifically discussed keeping the helper in place early in this thread.

90 vs 110 is harder to answer. I think there are varying approaches/perspectives on spring rate. It is worth noting that it's unknown whether the updated version of the kit has different shock valving to match the stiffer springs.

I'll note too that I spent 10+ years in several S2000s and KW also adjusted the spring rates on them as well at some point in the middle of product lifecycle. Some inquired with KW and was told that at least for that particular chassis they did not change the valving at all, it was just a change in spring rate as it wasn't a massive rate change.