Suspension Upgrade Advice

M

MichaelPorter80

Member
 Winchester Hamphire
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!
 
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.
 
mmm-five said:
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.
Click to expand...

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

Did you get camber plates to go with the coilovers?
 
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
 
mmm-five said:
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.
Click to expand...

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.....
 
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).
 
pcube said:
Any noise from the PSS10? And how is the ride comfort on street settings?

Did you get camber plates to go with the coilovers?
Click to expand...
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.
 
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)
 
MichaelPorter80 said:
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)
Click to expand...

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.
 
Argenta said:
Easypeasy - Eibach Pro springs.
Lower & much better ride, and cheap as chips.
Click to expand...
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).
 
mmm-five said:
I went for the Bilstein B16 PSS10 - and use them on almost their softest/highest setting for the road (about 15-20mm lower),
Click to expand...

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?
 
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.
 
beanie said:
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?
Click to expand...
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).
 
That’s not a bad idea for the rear. Thanks :thumbsup:

Other than the reinforcement plates which must add a few mm, I don’t suppose there’s anything for the front?
 
BMWZ4MC said:
Argenta said:
Easypeasy - Eibach Pro springs.
Lower & much better ride, and cheap as chips.
Click to expand...
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).
Click to expand...
Now, for trackdays I agree on them being too soft. I’ve done lot of trackdays on them and will swap for bit more hardcore KWV3.

However, trackdays are not on the table here, but everyday driving. Which at was my reply.

More tramlining sounds weird - did you still have 1mm toe in upfront? With maxxed camber, you might need even more.
Here, maxxed out camber wasn’t a demand either.

Michael wont get more tramlining out of just changing the springs, but as I found, a significant ride improvement.

So - simplest solution for better everyday driving - Eibach Pro springs
 
I was trying to reduce understeer on the track, hence running the geometry that I did. I can only comment on my own experience (albeit not a direct reflection of the OP’s requirements) - running OEM 224s, the tramlining lessened. With CSLs it was horrible.
Fitting Eibachs certainly made mine lower (and it looked better as a result) and I agree they were fairly inexpensive, but the ride was not a significant improvement over OEM.
 
beanie said:
Anyone know if the KW V3 allows you to keep standard height or fairly close?
Click to expand...

They claim -10mm front and -5mm rear, relative to stock, but you can safely make use of another 5mm or so of thread. I run at max height front (70mm of thread) and +3mm rear (23mm of thread) plus a 6mm spring perch spacer. The spacer is partly because I run a 35 profile rear, but mainly to provide enough adjustability to level up the rear left/right sides without sacrificing clearance.

The V3 spring rates are only slightly higher than stock (unlike the Clubsports) and provide a decent ride, even on our B roads. I suspect the damping is a lot better, even before you take into account adjustability, but I haven’t ever been able to do a back-to-back comparison. The inox construction is brilliant - just give them a good scrub every year and they come out like new.
 
I've rode in a car on V3s and it was excellent on the road, I'm on clubsports, I find them fine but they are definitely more track focused, I'd recommend V3s to answer your dilemma :thumbsup:
 
I just ordered a set of KW V3's for my TT RS. £300 off in the blackfriday sale. The TT's mag ride shocks are shot though, so I had and excuse.
Can't justify a set for the Z4 yet ...
 
You must log in or register to reply here.
Back
Top Bottom