Z4M handling issues

[SeeSaw]

I too am interested in the suspension options for the Z4M. I would be very interested to hear how the Bilstein B12 Pro-Kit goes - as that is one of the options that I've been considering.

From a simple search of manufactures options - the following kits seem currently available:

From Bilstein:
http://www.bilsteinsuspensionstore.co.uk/info-part...
Both Bilstein B12 Pro-Kit and B16 - PSS10

From KW:
http://www.kwsuspensions.co.uk/produktfinder/?rese...
KW Coilover V3

and from BC Racing:
http://www.bc-racing.co.uk/applications/bmw-coilov...
BR Series Coilover Type RA

Does anyone have experience of any of these? Any recommendations out there? The B12 kit from Bilstein and the BC Racing options seem very reasonably priced. The B16 and KW options which give you the added bonus of adjustability - are somewhat more expensive.

[nickrex]

SeeSaw said:

I too am interested in the suspension options for the Z4M. I would be very interested to hear how the Bilstein B12 Pro-Kit goes - as that is one of the options that I've been considering.

From a simple search of manufactures options - the following kits seem currently available:

From Bilstein:
http://www.bilsteinsuspensionstore.co.uk/info-part...
Both Bilstein B12 Pro-Kit and B16 - PSS10

From KW:
http://www.kwsuspensions.co.uk/produktfinder/?rese...
KW Coilover V3

and from BC Racing:
http://www.bc-racing.co.uk/applications/bmw-coilov...
BR Series Coilover Type RA

Does anyone have experience of any of these? Any recommendations out there? The B12 kit from Bilstein and the BC Racing options seem very reasonably priced. The B16 and KW options which give you the added bonus of adjustability - are somewhat more expensive.

I looked into all the adjustable options and after doing a load of research would favoured the kw v3's. For me though an adjustable set up wasn't really required as I do not intend on tracking my car, my priority was a good fast road set up. So I went for Bilstein B12's as they ticked the boxes for me. They are going on know and I'm waiting to collect it, I will let you know my feed back when it's done

[GordonL]

I went for the Bilstein B12 kit as well, ordered from Germany via eBay was cheapest by a few hundred pounds.

Geometry is standard BMW settings, local garage fitted them for a couple of hundred.

[nickrex]

GordonL said:

I went for the Bilstein B12 kit as well, ordered from Germany via eBay was cheapest by a few hundred pounds.

Geometry is standard BMW settings, local garage fitted them for a couple of hundred.

How did you find them, much of an improvement over stock?

[carl_w]

GordonL said:

I went for the Bilstein B12 kit as well, ordered from Germany via eBay was cheapest by a few hundred pounds.

Presumably this was pre-Brexit. Cheapest I can find on eBay now is €741 which is £677 vs £745 from Bilstein UK.

[GordonL]

Yes as I said before, transformed the car, especially in wet and damp conditions. Much more predictable.
I felt the front end was very vague at anything much over 55, emphatically not now!

nickrex said:

How did you find them, much of an improvement over stock?

[SeeSaw]

nickrex said:

I looked into all the adjustable options and after doing a load of research would favoured the kw v3's. For me though an adjustable set up wasn't really required as I do not intend on tracking my car, my priority was a good fast road set up. So I went for Bilstein B12's as they ticked the boxes for me. They are going on know and I'm waiting to collect it, I will let you know my feed back when it's done

Any news? How have you found the new suspension - did it meet all of your expectations and are there any downsides?

[S6OOH]

Be interested in the feedback post fitting of the Bilsteins

[nickrex]

S6OOH said:

Be interested in the feedback post fitting of the Bilsteins

I posted this on the Z4 forum shortly after getting my car back;



It looks noticeably lower and imo much better.

Much less dive and squat, particularly squat under acceleration. Something I thought the stock set up was awful for so very happy with that.

Ride seems no firmer but is definitely better with a more controlled feel.

Less roll around corners.

Front end seemed tighter, less prone to understeer. Didn't get chance to get on it early out if corners but I'd say the rear would have more grip as well.

I'm planning a good run up through the Brecon Beacons and on to mid Wales soon so will have a better idea of how it handles all the dips, crests, cambers, fast/slow bends etc etc after that but initial impressions are excellent, basically more body control and grip.


Since then I've been on a few really good runs and I'd say traction out of bends is much better as well. As a general whole, it looks great lowered, body control is in a different league, it's just a huge improvement over stock. Cost about £1k fitted and set up. Another £1k on top would get you a probably superior adjustable kit e.g KW V3's but for me these are about right, all things considered

[Billy_Whizzzz]

As an update I’ve had the B12 kit fitted to mine a couple of weeks ago plus the geometry set to more like CSL settings.

I have to say, the B12 kit makes the car feel like the suspension is broken. It isn’t just that the Z is now annoyingly low and scrapes everything, but that it crashes and thumps on every bump, making pressing on impossible and I simply avoid using the car now.

A complete disaster and wish I’d known how bad the B12 kit was. I’m ditching it next week for original suspension.

[ian in lancs]

ive driven my Z4M from new, for over 60,000mls, on standard M Suspension components and never had cause to criticise the suspension. Mileage including the ring, fast road and a little track.

[rassi]

Billy_Whizzzz said:

As an update I’ve had the B12 kit fitted to mine a couple of weeks ago plus the geometry set to more like CSL settings.

I have to say, the B12 kit makes the car feel like the suspension is broken. It isn’t just that the Z is now annoyingly low and scrapes everything, but that it crashes and thumps on every bump, making pressing on impossible and I simply avoid using the car now.

A complete disaster and wish I’d known how bad the B12 kit was. I’m ditching it next week for original suspension.

First time, I hear someone completely unhappy with the B12 kit.

Not a Z4M, I know, but fitting the B12 kit to my Z4 Coupe with 18” Z4M OEM wheels and tyre sizes, it fixed the ride and ride height (no scraping) and much better than the standard set up. Did you also change associated bushings etc?

[AW10]

It would be good to know what ride height you're running at. From memory the Z4M isn't over-endowed with suspension travel and if you're running it quite low you may be bottoming out the suspension, particularly the rear, when 2 up with a full tank.

[gav2612]

Not been on pistonheads for a while, but stumbled on this post. I've owned a Z4MC for nearly 5 years now and whilst as an overall package its been hard to beat for what I paid, I agree with the OP on the handling. I had the geo done and set as close to CSL settings as possible and that did make a marked difference to front end grip (maximum front camber with the strut pins pulled) It doesn't understeer as much now however pushed past grip limits, the car still tends to first understeer before a quick progression into snap oversteer if you push on harder. It doesn't inspire confidence and needs quick reactions to catch it. Over 15,000 or so miles I've got used to this and I would say its one of the best and quickest point to point road cars I've owned (had 996 911 carrera, E46 M3 and TVr chimera in the past) Drive flat out and past grip levels of the car consistently (not something you do regularly on the road) and the E46 m3 was much better balanced and more fun.

[Polarbert]

I'm not sure if my yank version has different set up for suspension, but I've always found it okay and relatively progressive to slide. The roads here in San Diego are dog ste though and so can never really have the confidence to get sideways much.

[MrTops]

Hi, I'm thinking about buying a Z4M coupe - gorgeous shape and one of the best engines ever made by BMW. Can anyone recommend a UK specialist who could help with the suspension setup?

[Planman]

Hi, I find the factory suspension set up on mine ok, but its on standard 18 inch wheels. A lot cars have upgraded 19 inch CSL wheels which look lovely but I can't imagine its going to assist ride quality.

I have no doubt the suspension can be improved, but the standard spec is no way as bad as it is sometimes presented. I guess it also depends whether the car is for everyday use or weekend use.

[survivalist]

I agree with the previous poster, to me it's fine on 18s.

That said there's a few useful threads on the Z4-forum

https://z4-forum.com/forum/viewtopic.php?f=9&t...

https://z4-forum.com/forum/viewtopic.php?f=9&t...

[Billy_Whizzzz]

Had one for 4 years. Tried a number of set ups and never found anything that gave me any confidence or handled well compared with all the other M cars I’d had. So wanted to like it but never gelled. Sold it and haven’t missed it one bit.

[VeeTenM]

https://www.pistonheads.com/gassing/profile.asp?h=...

https://www.instagram.com/02.slo/

Has a nice a nice modded one, I would ask him about suspension.