Your experiences of aftermarket suspension on the Z4 MC

ChawenHalo said:
Right on :) after much consideration I've gone for the following. Delage Sport will be doing the fitting and suspension settings for fast road and track.

(sorry translation from french may be a little off)
BILSTEIN - B16 PSS10
H&R Anti Roll bars front & rear
Front strut brace
BMW Motorsport off centre front suspension joints
Rear suspension bushes
Rear suspension arm blocks (to stop wheel movement during cornering) Delage's own.

Will post pictures updates as and when. Hopefully next week :D .

Nice to go to a reknowed preparator. He had a good lisen to the car, plugged it in and was ple&ased to see that the car was "clean". Price was decent too. :thumbsup:
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Excellent! I'm sure that you'll appreciate the difference. Please post your review when you've had time to assess. :thumbsup:

From my recent experiences, can I suggest that once you've got the suspension set up to your liking, you experiment with tyre pressures. I've found less pressure than recommended improves grip levels, especially at the rear.
 
Fascinating read!! :D

Really great to see a healthy debate about this - trouble is, I have a feeling life might get a touch expensive - picking up my Z4 M coupe this Sunday and already thinking about KW variant 3s... :evil:
 
BMWZ4MC said:
Beedub said:
braking hard in my car with the stock setup was plain scary..... the car would stand on its noise and the back would start to move out...... when the car was stock however, i loved the stock suspension with alignment changes, not ideal but, pretty damn good imo...... see the video below stopping from 100mph.... as i finish the straight line dash and begin braking, the car need corrective steering under braking..... f***ing scary on a track with no run off.

http://www.youtube.com/watch?v=so5q1NVOIC4
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Beedub, is that video with entirely stock suspension, the car looks like it's riding lower than stock? Also, were the brakes standard, tyres good / well inflated, tarmac in good condition etc?
Only I've braked as hard as that from >100mph on track and I've never experienced the rear trying to overtake the front like that :o I agree, it would have scared the sh** out of me too!
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This does happen a little from high speeds with camber on the track and locking the wheels. This is exagerated if you're using rear pads as agressive as the front, causing the rear to lock. As the front pitches forward braking there is less weight on the back. As the z4m has no brake balance controler, the rear still gets a strong amount of braking force applied causing it to lock then side step depending on your steering input and brake pedal pressure. Whilst an uprated suspension will make a big difference ro that pitching, a simpler and cheeper solution is to simply have less aggressive brake pads at the rear. :driving:
 
OK, all done. It came out of Deloage sport a copuple of weeks ago. Not done a track day yet but here my first impressions on the road as I've knocked up 1000+ km on various roads before writing this review:

-Its definately all a bit firmer and less comfortable at town speed
- steering is more direct and precise with a lot more feedback
- car tramlines 15 to 20% more
- rear is far more planted, does not loose traction and has way more push
- car rolls far less and feels a lot gripper in both slow and fast corners
- I have far more confidence in entering corners and accelerating out
- Braking is vastly improved with the car pushing down on the ground rather than so much pitching at the front.
-body control seems far more effective on both bumpy roads and long weepers BUT it is also more lively, so it keeps you busier / on your toes/ focused
- the Bilstein have valved etc a B16PSS10 specific for the Z4MC. bear in mind there are alsop changes on my car which include H&R ARBS, suspension joints and full geometry changes front and rear (with various bits added)

As a conclusion I would say for an anyone looking for more road comfort the changes I have made are not worth it and conterproductive. ACS perhaps has done a better job but I sispect OEM the suspension is as good as it can get for day to day driving, hence the hard rear and soft front.

I am pleased with the changes as its gives the handling the feedback, detail and precision I was looking for on the road although I was somehow hoping to improve comfort too :oops: ). I suspect the real difference will come on the track, where OEM, its a bit of a dog (albeit a very pleasent and easy one.) Will report back as soon as I've done a track day (which won't be very long I assure you :D )

In the meantime, here a few piccies for you (its finally stopped raining over here).


 
ChawenHalo said:
-Its definately all a bit firmer and less comfortable at town speed

As a conclusion I would say for an anyone looking for more road comfort the changes I have made are not Worth it and conterproductive. ACS perhaps has done a better job but I sispect OEM the suspension is as good as it can get for day to day driving, hence the hard rear and soft front.
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Your remarks really surprise me!
Since the B16PSS10 specific for the Z4MC is an adjustable system, what settings have you set it up on? Have you tried adjusting these settings yourself? What is the diameter of the wire of the springs F&R?
 
yep its adjustable with a very simple knobby at the bottom which is easily accessible. (you hear the clics, no spanner required. 1 = softest and 10= hardest. To be fair as the overall car is better "suspended" its is far more pleasent when getting on. Just not town speeds.

The guy told me the problem with any aftermarket suspension for road and track is that 1 is never soft enough for the road and 10 never hard enough for the track. Bear in mind these guys successfully prepare race cars for a living and have installed 100's of kits on road cars and race cars.

There are are other adjustments to be made on the kit but frankly, as it a pro thats made them I'm reluctant to play with them other than precribed (1 for road, 10 for track). I"ll have to look into it as I have no idea really what "parralel damping adjustements are vs rebound and compression.


 
ChawenHalo said:
yep its adjustable with a very simple knobby at the bottom which is easily accessible. (you hear the clics, no spanner required. 1 = softest and 10= hardest. To be fair as the overall car is better "suspended" its ois more pleasent when getting on. Just not a slow town speeds.

The guy told me the p^roblem with any aftermarket suspension for road and track is that 1 is never soft enough for the road and 10 never hard enough for the track. Bear in mind these guys successfully prepare race cars for a living and have insta
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My ACS Racing are essentially a BIlstein PPS9, where 9 is the softest and 1 is the stiffest.

ChawenHalo said:
I have no idea really what "parralel damping adjustements are vs rebound
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All that means is that, when you adjust compression you also adjust rebound (and vice versa) by the same amount.

You also say: "bear in mind there are alsop changes on my car which include H&R ARBS, suspension joints and full geometry changes front and rear (with various bits added)"

I bet you've increased the negative camber and possibly got a tad of toe out with your geometry changes. Since you've now got H&R ARBs, which are about 88% stiffer on the front ARB on the middle setting than the OEM, and you've also got stiffer front springs than OEM, you won't need any increase in negative camber. I found that removing the pins from the OEM front top mounts with my suspension changes, made the car way too twitchy, like you report, so I reverted to OEM front -ve camber and I'd already reduced the rear camber ages ago.

Here's a photo of my car at The Ring last month which shows that when cornering hard, the lateral bodyroll is such that the outside front wheel becomes vertical, thus making the contact patch as large as possible across the full width of the tyre.

As I see it, the beauty of adjustable suspension is that you can get the best of both worlds: a great fast road car and a great track car, BUT you have to make adjustments to suit the conditions. I find that softish settings are best on the road.

48Front.jpg
 
That's exactly what I'm hoping to get to be able top do but as my understanding is too limited at the mo, I feel more comfoprtable in letting a proffessional do it. I'll get advice from the pros running BMW's on the track.

BTW Delage changes the top mounts to reionforced onces. He's also added plates.

I've asked them to give me the détails and settings of what they've done. It was quite funny to see that he wazs quite "coy" about what he did. Friendz who are pros in the business told me that it was normal he did not give mee all détails on his work as it was his "marque de fabrique" ie: his little trade secrets. The one thing they insisted on is that he signs off the chassis and puts his name on the car.

On thing I did forget to say is that B16PSS10 looks like a real quality piece of kit, I was dead impressed. One other thing that really surprised me was how dismissive he was on KW appart from the Clubsport version. He just said, "not in a million years, not in my shop. JUst bnot suitable for the road. They work great for the 1 st few 1000 km they its all off."
 
Having just really pushed my car on the track ill report back with an update here.... Very pleased with the club sports , they do however need relatively regular rebuilds .... At 125 quid a corner!!!! Wooooaaaa!!!


Sent from my iPhone using Tapatalk
 
How regular Beedub? These are on my shopping list - in fact I'm planning to order them in the next couple of weeks so they'll be waiting for me when I get home (along with a collection of other toys :D )
 
ChawenHalo said:
That's exactly what I'm hoping to get to be able top do but as my understanding is too limited at the mo, I feel more comfoprtable in letting a proffessional do it. I'll get advice from the pros running BMW's on the track.
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I think the best way to understand suspension settings is to make changes then go and test-drive to see how the car's behaviour/handling changes, and then make some more changes in the opposite direction then test drive and so on. If you make written notes of the different settings you try you can then easily go back to the settings that you had as your starting point, as a reference point. If you try the car with full stiff all round first and then later try full soft, you can then progressively hone in on the settings that work the best for you. You'll soon get a feel for your settings and what changes you need to make. You'll find with a car like the Z4MC the front suspension should be stiffer at the front than the rear, and the rear suspension settings have the greatest influence on your perception of the "ride", because your essentially sitting just in front of the rear axle.

ChawenHalo said:
The one thing they insisted on is that he signs off the chassis and puts his name on the car.
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Pretentious bollocks! :wink:
 
I agree with the theory there Exdos, however, I'm no proffesional testdriver and frankly I don't think I could not accurately prétend to know what effects the changes I'm making are having on the car, especially when it comes to on the limit behaviour.

You're absolutely right though, the trade secret thing whilst I can appreciate it on a business level is rather pretencious. But hell, he's the pro, it works brilliantly, I got a good price top service and all the confidence I need. Although on the price thing it's still a big budget all hiden away behind the wheels!
 
ChawenHalo said:
I agree with the theory there Exdos, however, I'm no proffesional testdriver and frankly I don't think I could not accurately prétend to know what effects the changes I'm making are having on the car, especially when it comes to on the limit behaviour.
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Neither am I, but you don't have to drive the car at its limits to discover how different settings affect the behaviour and handling. With some of the "wilder" settings, you'd be mad to even try! Personally, I love testing out mods of all kinds to see what they do, and you begin to get a real feel for your car when you've experienced it in many different guises. Be bold! try stiffening the front dampers as a start, then softening the rears..... :thumbsup:
 
exdos said:
ChawenHalo said:
I agree with the theory there Exdos, however, I'm no proffesional testdriver and frankly I don't think I could not accurately prétend to know what effects the changes I'm making are having on the car, especially when it comes to on the limit behaviour.
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Neither am I, but you don't have to drive the car at its limits to discover how different settings affect the behaviour and handling. With some of the "wilder" settings, you'd be mad to even try! Personally, I love testing out mods of all kinds to see what they do, and you begin to get a real feel for your car when you've experienced it in many different guises. Be bold! try stiffening the front dampers as a start, then softening the rears..... :thumbsup:
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I did by 2 clicks and its made the front more skittish. I then reverted back to 1 and it was more planted. I'll get to really see the difference on the track though, so I can't wait!
 
BMWZ4MC said:
How regular Beedub? These are on my shopping list - in fact I'm planning to order them in the next couple of weeks so they'll be waiting for me when I get home (along with a collection of other toys :D )
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ideally every 35k less depending on usage.... As they are track units, they are going to be used hard!! After my last sprint session i can honestly say these were for me the right choice, on softest setting they are definitely driveable on the road, 110% still avoiding all the drain covers and bumps in the road which sometimes make me wince, but i can hustle this car along at an incredible rate with these coilovers in place, and on the track, where they belong, they are sublime, the car is glued to the road and transitions are like a guided missile, you'll be hunting down some serious machinery with these in place.... They are completely silent and offer upto --3.7 negative camber, mines currently set at -3. and due to extreme use the are wearing perfectly even, hell the outer shoulders are still taking a beating..... The construction of the actual damper is wonderful, and they look brand spanking new to this day, the shperical uniball mounts do increase Nvh significantly and also transmit a very clear message to the steering wheel.... i LOVE these..... and you will too....

heres the car FULLY loaded on a very tight hairpin, entering and HOLDing a solid 45mph +, im on the absolute limit of grip, theirs also a heavy passenger in the car..... the car no longer dips at all during acceleration and breaking, it stays as flat as a pancake... if you cant tell.... im over the moon with these.... i was soooo pleased that my passenger stated " This is the best handling road car ive ever been in" and this was the car on bog standard Ps2s ( wanted to kill them off once and for all), with cups on its fair beyond my skill level and is actually scary, not fun to drive.... i keep it on road tyres to keep the levels within where i feel comfortable... with the the cups the car is competing WELL above level, matching the slower/medium level caterhams..... The r8 v8 that goes their isnt even on the same playing field.....





braking as hard as i can from 100 mph.....


this thread is awesome BTW..... imo the best resource for changing your suspension on the z4m, on the net....

next up for me??? poly FCABs.....
 
What's FCABs Beedub?

Interesting what you say about R compound tyres. The fella that does most of the work on my car also advised me against as breakaway is far more sudden and handling tricky. I'm stuck on MPS2 YTD as I can't find any other performance tree OEM size... :(
 
the FCABs just press in place and will cut the slop from the stock FCABs.... if youve got a few miles on the car these will make a nice difference...
 
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