Suspension Upgrade Advice

[MichaelPorter80]

I know this is a big topic, but would love to get everyone’s view point. I have a Z4MR 2006 on 59k. I have done quite a lot to my car as some of you may have seen on my update post. I am not thinking of upgrading the suspension, and so want people’s views on the right solution. First some key info.

- I am not planning to track the car
- I would like it to be lower than stock but not ridiculous
- I am keeping the stock 18” wheels (I love them)
- I want to maintain the ride comfort but improve suspension performance.
- I am thinking coil over just because they’re an upgrade and to get the same ride comfort but have the car lower they seem to be the best option.

So with all this in mind... what do people think? I am a complete noob on this stuff by the way!

[mmm-five]

I had almost the same criteria, with the exception of wanting to be able to tweak them for track use too.

I went for the Bilstein B16 PSS10 - and use them on almost their softest/highest setting for the road (about 15-20mm lower), and then adjust them another 20mm lower and stiffen out the bump/rebound for track use.

I was doing 20,000+ miles a year on them too - with an annual service (not a rebuild, just cleaning/checking them over) as part of my annual Inspection 2 process. They've probably got 4 years and 50,000 miles on them now - plus a few Ring trips and track days under them.

[pcube]

I had almost the same criteria, with the exception of wanting to be able to tweak them for track use too.

I went for the Bilstein B16 PSS10 - and use them on almost their softest/highest setting for the road (about 15-20mm lower), and then adjust them another 20mm lower and stiffen out the bump/rebound for track use.

I was doing 20,000+ miles a year on them too - with an annual service (not a rebuild, just cleaning/checking them over) as part of my annual Inspection 2 process. They've probably got 4 years and 50,000 miles on them now - plus a few Ring trips and track days under them.

Any noise from the PSS10? And how is the ride comfort on street settings?

Did you get camber plates to go with the coilovers?

[Jembo]

I went for the Bilstein B12 kit, that has softer rear springs & stiffer fronts - if you’re not tracking the car, coil overs are a very expensive alternative (IMO)

The rear is perfect, taught & supple, though despite it being fantastic on good tarmac I haven’t been able to live with the harshness of the front springs on the cr@p potholed & bumpy Kent roads.

So, I (well a m8) simply swapped the Front eibachs back to the standard springs & the ride IMO is now perfect

[AndyBeech]

I had almost the same criteria, with the exception of wanting to be able to tweak them for track use too.

I went for the Bilstein B16 PSS10 - and use them on almost their softest/highest setting for the road (about 15-20mm lower), and then adjust them another 20mm lower and stiffen out the bump/rebound for track use.

I was doing 20,000+ miles a year on them too - with an annual service (not a rebuild, just cleaning/checking them over) as part of my annual Inspection 2 process. They've probably got 4 years and 50,000 miles on them now - plus a few Ring trips and track days under them.

Also thinking about this B16's, just waiting for a good deal on them. Any reliability issues at all in your ownership? Only bad thing I've heard about them compared to the KW's for example which are about the same price.....

[Franzino]

I fitted the PSS-10 without any reinforcement and no different top mounts on my Z4M. The driving feel with the PSS-10 was great and for street and Nurburgring I did not put them that hard (switching between hard - soft is not that hard to do on PSS-10). My Z4M was still a daily driven Z4M that saw some trackdays a year.

The downside of the Bilstein for me was reliability... I had 2 PSS-10 dampers replaced...one for making to much noise, one for leaking. All under warranty; but was a lot of waisted time
Same story with the Bilstein set (B12 Pro-Kit) that was fitted on my e46 325i. Drove rather well but also issues with dampers needing replacement (also under warranty).

[mmm-five]

Any noise from the PSS10? And how is the ride comfort on street settings?

Did you get camber plates to go with the coilovers?

No noises that come to mind, and that's on road or track.

I found the ride firmer in that the car didn't roll as much, but it absorbs the bumps/undulations better to dampen out the twitchiness of the OE suspension.

Didn't buy any extra camber plates, and just removed the limiting pin on the fronts to adjust to a fairly neutral geometry for the road.

[MichaelPorter80]

Thanks for this chaps, does anyone have the KW Coilovers and if so which set, the Bilsteins seem a bit unreliable... is the difference between lowering spring upgrades and coil overs marginal then, unless you’re tracking the car and want adjustability (which I don’t)

[Argenta]

Easypeasy - Eibach Pro springs.
Lower & much better ride, and cheap as chips.

[BMWZ4MC]

Thanks for this chaps, does anyone have the KW Coilovers and if so which set, the Bilsteins seem a bit unreliable... is the difference between lowering spring upgrades and coil overs marginal then, unless you’re tracking the car and want adjustability (which I don’t)

I have KW Clubsports (with KW camber / castor plates and OEM front strut tower reinforcement plates; RE rear strut mounts; H&R ARBs front and rear; Turner RTAB limiters; VT competition engine mounts and an OEM strut tower brace). This set up is absolutely amazing on glass-smooth tarmac and has transformed the car into something seriously fast. However, the Clubsports are designed for track use primarily, so they make the ride fairly unpleasant on poor roads and the car can be very skittish on broken surfaces. I’ve had no reliability issues but the suspension can be noisy occasionally.
If you’re not taking your car on a track, Clubsports wouldn’t meet your needs. KW have other, road-focused setups that have had favourable reviews here.

[BMWZ4MC]

Easypeasy - Eibach Pro springs.
Lower & much better ride, and cheap as chips.

For a while, I ran Eibachs / OEM dampers with as much negative camber as possible at the front. I found that improved track behaviour over the OEM setup. However, tram lining was a big problem, especially with 19” wheels, and the handling remained somewhat unpredictable (hence making the changes I’ve listed above).

[beanie]

I went for the Bilstein B16 PSS10 - and use them on almost their softest/highest setting for the road (about 15-20mm lower),

I’m surprised and disappointed that that’s the highest they’ll go. I was hoping to do a suspension overhaul next year and was considering the Bilstein PSS but I really can’t lower it at all thanks to my garage entrance. I reckon I’ve got 5mm to play with!

Anyone know if the KW V3 allows you to keep standard height or fairly close?

[MichaelPorter80]

I think I have decided on the B12 kit, the car is 13 years old so lowered springs new dampers and a refresh of all the bushes will do the trick I am thinking. Thanks for all the input.

[mmm-five]

I’m surprised and disappointed that that’s the highest they’ll go. I was hoping to do a suspension overhaul next year and was considering the Bilstein PSS but I really can’t lower it at all thanks to my garage entrance. I reckon I’ve got 5mm to play with!

Anyone know if the KW V3 allows you to keep standard height or fairly close?

You could always add a thicker upper spring pad.

IIRC from a previous post on here, standard is 5mm, and you can get 14.5mm from BMW for about £12 - part no. 33531094754 (it's for an e46, but they use the same 5mm pad, so I assume the 14.5mm will fit too).

[beanie]

That’s not a bad idea for the rear. Thanks

Other than the reinforcement plates which must add a few mm, I don’t suppose there’s anything for the front?