E86 Suspension - Help me understand the options

[Fred Smith]

Yeah, my car is on 18’s.

Given the number of these running 19inch CSL’s you should be fine providing the offset isn’t too aggressive

Fronts are ET35 according to the manufacturer (Veeman are an INCREDIBLY helpful company when you phone them for support in my limited experience.)

Rears are ET42 or ET45 apparently.

Is that "too aggressive"?

[enuff_zed]

Yeah, my car is on 18’s.

Given the number of these running 19inch CSL’s you should be fine providing the offset isn’t too aggressive

Fronts are ET35 according to the manufacturer (Veeman are an INCREDIBLY helpful company when you phone them for support in my limited experience.)

Rears are ET42 or ET45 apparently.

Is that "too aggressive"?

I had a square set of 18x8.5 on one and they were ET38. No problem at all.
My wife's E85 is running 108s, so the rears are 18x8.5 ET50. She has 20mm spacers taking it to ET30. Still fit nicely. 19s maybe a little tight but you are only really going to be at OEM +5mm spacer territory with your ET45s.
Your fronts will be like OEM +12mm spacer.

[Fred Smith]

Yeah, my car is on 18’s.

Given the number of these running 19inch CSL’s you should be fine providing the offset isn’t too aggressive

Fronts are ET35 according to the manufacturer (Veeman are an INCREDIBLY helpful company when you phone them for support in my limited experience.)

Rears are ET42 or ET45 apparently.

Is that "too aggressive"?

I had a square set of 18x8.5 on one and they were ET38. No problem at all.
My wife's E85 is running 108s, so the rears are 18x8.5 ET50. She has 20mm spacers taking it to ET30. Still fit nicely. 19s maybe a little tight but you are only really going to be at OEM +5mm spacer territory with your ET45s.

Thanks.

[INSTALLITE]

Can I jump in here? I have E86 - Originally with sport suspension - Replaced with Eibach Pro srpings and B4's and the ride is dreadful. I see people on here say they are a good combination, but from what I have found, the B4's are for non-Sport cars. So I have coupled Sport springs with non-Sport dampers. I'm about to change these for a set of Koni yellow. Bilstein recommended B8's but they are hard to find. Wheels are standard 18 inch, and you can feel every bump and crease in the road, so much so that I just don't want to drive it until it's sorted. Any thoughts are welcome.

[Special Kay]

Can I jump in here? I have E86 - Originally with sport suspension - Replaced with Eibach Pro srpings and B4's and the ride is dreadful. I see people on here say they are a good combination, but from what I have found, the B4's are for non-Sport cars. So I have coupled Sport springs with non-Sport dampers. I'm about to change these for a set of Koni yellow. Bilstein recommended B8's but they are hard to find. Wheels are standard 18 inch, and you can feel every bump and crease in the road, so much so that I just don't want to drive it until it's sorted. Any thoughts are welcome.

I don't know an awful lot about car suspension, but from the setup you have, your using OE b4 suspension with slightly lower slightly stiffer springs. You should not be having the issues your encountering. The ride and quality should be more or less standard and back to OE spec. I would be looking at other areas. I would be checking all rubber bushes, connections and mounts etc for wear and tear, getting my alignment checked and speaking to my mechanics before throwing money at more suspension components. The way I see it, if the surrounding perishable components aren't addressed, then no amount of money thrown on suspension legs and springs is going to make the car handle well.
This is just my humble opinion, I'm sure, other more qualified members will offer a more targeted response.

[Fred Smith]

Can I jump in here? I have E86 - Originally with sport suspension - Replaced with Eibach Pro srpings and B4's and the ride is dreadful. I see people on here say they are a good combination, but from what I have found, the B4's are for non-Sport cars. So I have coupled Sport springs with non-Sport dampers. I'm about to change these for a set of Koni yellow. Bilstein recommended B8's but they are hard to find. Wheels are standard 18 inch, and you can feel every bump and crease in the road, so much so that I just don't want to drive it until it's sorted. Any thoughts are welcome.

[Most advice based on recent research, not experience].

B4s are for SE and M-sport level cars and are capable of handling 40mm front and rear lowering - your einbachs are 30/20 or 30/30. These items are designed to work together. B4s are slightly stiffer than true OEM level dampers like Sachs.

B6s are for those who want a firmer, sportier ride. B8s are for those who want a B6-firmness ride, but want shocks specifically designed for lowering springs.

Given you want more comfort the obvious things for you to do are switch to 17s and get more rubber; switch the B4s to sachs, or switch the eibachs to stock M-Sport or even SE level coils.

Koni might be a good option for you - they seem to claim to be a comfortable sporty option, though on the face of it you already have a fairly comfortable but somewhat sporty, lowered option and want more comfort, so not sure Konis will do it for you.

The other thing to say... to my mind the Z4 is part sports car, part GT... and being part sports car it is part "not built for comfort". Early days for me, but I love my E86... but it's not the car I'd choose if "feel[ing] every bump and crease in the road" was a bad thing.

I cannot stress highly enough that I am new to Z4 world and not some car guru... part of the reason I am posting is in the hope that others will tell me where I am mistaken or where I am missing something I need to know.

[INSTALLITE]

Special Kay and Fred, many thanks for your input.
Something my mechanic considered was bushes although he couldn’t get any “play” with a pry bar, the trailing arm bushes do look a bit grotty, so this is the next thing to check properly.
My problem is I’ve never been in an E85/86 so didn’t know what to expect, but I sure as hell wouldn’t be buying a new car that rides like this one.
Sure I expect the thing to be stiffer but not uncomfortable.

I’m not going to be ordering any new stuff until those things are checked/replaced and I’ll update this when I know more as I bet I’m not the only one with the same problem.

Thanks again.

[INSTALLITE]

Special Kay and Fred, many thanks for your input.
Something my mechanic considered was bushes although he couldn’t get any “play” with a pry bar, the trailing arm bushes do look a bit grotty, so this is the next thing to check properly.
My problem is I’ve never been in an E85/86 so didn’t know what to expect, but I sure as hell wouldn’t be buying a new car that rides like this one.
Sure I expect the thing to be stiffer but not uncomfortable.

I’m not going to be ordering any new stuff until those things are checked/replaced and I’ll update this when I know more as I bet I’m not the only one with the same problem.

Thanks again.

[x-driver]

I can comment the Eibachs and Lesjofors from my experience with them on my E39 5 series.

Years ago I went from SE suspension to Lesjofors springs and Sachs dampers (for sport suspension). At the time I didn't want the car to get too low and too stiff. It certainly didn't get too stiff but I didn't like the height - front too high, rear too low, not to mention what happened if some people seated in the back - as if the springs were broken.

So I dumped Lesjofors and went with Eibach Pro kit. The car is still comfortable, maybe almost a little too soft. The front sits really low (with time it dropped even lower, I'd now wish to lift it back up for ~10mm) while the rear sits perfectly for my taste.

One more thing about Eibach. They offer Pro kit and Sport. You guys are mentioning 2 options for Eibach, 30/20 and 30/30. I guess the latter is the Sport version. This is a very stiff spring so be careful when choosing (tested on F30 3 series).
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Back to E85. My car originally has M-sport suspension which haven't been touched yet I believe. It sits quite high for a sport suspension, especially the rear likes to stand higher on every just slightly uneven surface, making the car look funny. Is this supposed to be normal?

See a picture of what I mean (an extreme example):

NKN_7666-8.jpg (185.32 KiB) Viewed 206 times

NKN_7867-22.jpg (216.75 KiB) Viewed 206 times

Otherwise it stands something like this:

NKN_7811-4.jpg (175.5 KiB) Viewed 206 times

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I can provide a photo of an E85 with SE suspension, but (claimed) Eibach springs:


Comparing to other E85/86s with Eibach this one seems to stand too low. The owner however never complained about ride quality, despite running 19"s.

______________________________

Here is another E85 with Bilstein B3/Lesjofors springs combo, unknown dampers. Before the mentioned springs there were some really low mounted on the car, causing problems on MOT track and rubbing with 2 people in the car. He changed the springs but left the dampers so my guess is they are probably some for lowered suspension.

This one actually sits a bit lower than mine on original M-sport suspension.

[Z4Mariner]

Hi Installite -

I'll just add a encouragement to experiment with tire pressures, unless you've already done that. My E86 with fresh M-sport suspension (and B4's) can change character quite a lot with only a few PSI change in tire pressures. I typically run about 31 PSI front and 32 PSI rear. If I go much higher, the rough roads I have in my area feel 'crashy'. My tires are non-runflat Michelin PS4AS - 225/40R18 front and 245/40R18 rear, on a square set of BMW 224 wheels (18x8's).

[STC_Zed]

Can I jump in here? I have E86 - Originally with sport suspension - Replaced with Eibach Pro srpings and B4's and the ride is dreadful. I see people on here say they are a good combination, but from what I have found, the B4's are for non-Sport cars. So I have coupled Sport springs with non-Sport dampers. I'm about to change these for a set of Koni yellow. Bilstein recommended B8's but they are hard to find. Wheels are standard 18 inch, and you can feel every bump and crease in the road, so much so that I just don't want to drive it until it's sorted. Any thoughts are welcome.

Mine is on B4’s with Eibachs, 18 inch wheels with none run flat tyres.

It’s certainly not a great ride, but I wouldn’t say it’s uncomfortable. Firm yes but I think the road noise is far more annoying and intrusive.

[INSTALLITE]

Can I jump in here? I have E86 - Originally with sport suspension - Replaced with Eibach Pro srpings and B4's and the ride is dreadful. I see people on here say they are a good combination, but from what I have found, the B4's are for non-Sport cars. So I have coupled Sport springs with non-Sport dampers. I'm about to change these for a set of Koni yellow. Bilstein recommended B8's but they are hard to find. Wheels are standard 18 inch, and you can feel every bump and crease in the road, so much so that I just don't want to drive it until it's sorted. Any thoughts are welcome.

Mine is on B4’s with Eibachs, 18 inch wheels with none run flat tyres.

It’s certainly not a great ride, but I wouldn’t say it’s uncomfortable. Firm yes but I think the road noise is far more annoying and intrusive.

I have learnt to live with the road noise. I suppose I could do with comparing notes with an owner in the Manchester UK area. This is the only Z4 I have ever been in, so I don't know what it should feel like.