Bilstein B16/PSS-10 makes noises. Fails! Opinions?

[Franzino]

I know that on the US Z4 forum they are keen on corner weighting, but I think that most of the advocates of that do "Autocross" driving short courses around cones in very flat car parks. I cannot see how corner weighting can really be of any benefit when driving The Ring.

Looking at your two different geometry settings, in your first one, after adjustment, you had toe out at the rear, which would definitely make the car turn much quicker, whereas in your second settings, you have toe in at the rear. I have my front and rear set at almost zero toe and I find that this gives me a predictable steering response and turn-in. I see you also still have the possibility to increase front camber, so it might be worthwhile increasing it too, because this will also increase turn-in.

Your evaluation is 100% correct… I was thinking exactly the same thing.
I want to try the following settings and see how the result feels...
Front camber: -1*40 / -1*45 (if possible)
Front toe: standard settings
Rear camber: standard settings
Rear toe: -0*20'

[exdos]

If you get another alignment done to your desired settings, you should get the technician to measure the rear toe settings at maximum and minimum points of adjustment, before setting up to your requirements, so that you know the range of adjustment. If after test driving at The Ring you are not completely happy with the settings you have, you could easily readjust (i.e. increase or decrease toe) as a DIY by adjusting equally on both sides. Until you've tried a few different settings you can never know whether the set-up is optimum for you or not, and the reason why I do my own alignments is so that I can easily experiment with settings to arrive at the handling I like best.

I hope those settings work best for you!

[ChawenHalo]

pressumably if you move to 18" wheels ( even going as far as forged ) you can have a lower damper setting whilst maintaining effective the spring rate as if you where on harder dampers and 19"?

[exdos]

pressumably if you move to 18" wheels ( even going as far as forged ) you can have a lower damper setting whilst maintaining effective the spring rate as if you where on harder dampers and 19"?

For a fixed rolling radius, it's more related to the height of the sidewall of the tyre, which of course is related to the diameter of the alloy rim. The larger the sidewall of the tyre the stiffer the damper setting can be, so as the sidewall height reduces the suspension needs to get progressively softer. The physics for this is two springs in series: i.e. suspension spring + tyre wall. Different makes and models of tyre, even of the same tyre wall height, and tyre pressures can produce different effective "spring rates" for the tyre.

This is the reason why I think that manufacturer's (and any one else's) recommended settings for adjustable suspension should be used as a guide only, because the suspension needs to be adjusted by a "suck and see" approach and because different tyres have a very big influence on the suspension settings required: the only way to find out what is best is by trial and error and for me, there's nobody better for adjusting suspension and tyre pressures and test driving your car than yourself.

[Franzino]

I went on holiday and my Z4M stayed for 2 weeks with my M-specialist to check out the noise that was still coming from the front of the car when hitting small bumps on the street. The noise started after the fitment of the Bilstein suspension in 2014.

They now checked every bit of the front suspension and found nothing was technically wrong or damaged.... They checked if the firewall braces were tight enough. It is common knowledge that if the bolts of the firewall braces are loose they can make noise. But every bolt was correctly fixed and there was zero movement when pulling the firewall brace by hand. As a final test they removed the OEM BMW strutbrace and the firewall braces and did the same test run. The typical rattling noise was gone...! They fitted the OEM BMW strutbrace again and the noise was still gone...so back to fitting the firewall braces and yes the noise was back... I went home and I did the test myself (removing and refitting the firewall braces) and had the same result when test driving on a bumpy road!

So afters hours of testing it is finally know what makes the noise.... The strange thing is, this noise started from day 1 after the Bilstein suspension was fitted (never heard it before). So what to do now??? The firewall braces need to be fitted and so the the annoying noise is coming back.... When pulling the firewall braces, then there is zero movement! When closely investigating the firewall braces mounting point on the strut towers, then you can see some really small cracks in the mounting points under the mounting plate of the strutbrace (but nothing alarming in my opinion)... I will try to make pictures of the cracks this week (so you guys can see what I mean with small cracks). In my opinion it does not make 100% sense that these small cracks could make the firewall braces move and create the noise... If the firewall brace mounting plates would be loose (like in this case: http://www.zpost.com/forums/showthread.php?t=298573) then it could totally explain the noise... But in my opinion is now not the case, because there is no movement in the firewall braces mounting plates. So maybe the problems is the firewall braces themselves.....but how could they create noise if they are not moving?

You can say; do a test! Order 2 now mounting points for the strut tower and get them spot welded on....do a test drive and see if the noise is gone. That not so expensive to do and sounds like something that can be done. The official BMW dealer will not do this (already checked), but my M specialist or a body repair shop can do this welding. Problem; welding on the chassis is not legal for the yearly MOT vehicle inspection in my country... If they notice it on the inspection then it will result in a car that will be denied road access! It's true; I know about people who had this happen after the MOT inspection spotted a small aftermarket spot welding on the chassis. This resulted is a really expensive operation to get the car back to street legal....

So then there is the option of buying the rather expensive Rogue engineering race brace (http://www.ca-int.co.uk/variants-cGFyZW ... 0MQ==.html)
This Rogue engineering strutbrace that has some extra stiffening on the spot were the firewall braces are connected on the struts. http://www.zpost.com/forums/showthread.php?p=12491034



But I have read that the fitment of this item is not 100% and it needs a lot of tweeking to fit correctly? 2 other downsides; for work on the engine you will always have to remove the entire strutbrace (and not only the middle part as on the OEM BMW strutbrace I have fitted now). The other downside may be that the noise is still there....and I have bought something that I did not needed and is no solution for my problem.

The OEM firewall braces are hollow, so maybe they are some sort of resonance room and create noise...? A firewall brace from strong strut is not hollow and could maybe delete the noise? http://www.ca-int.co.uk/variants-cGFyZW ... zMjE=.html

[Beedub]

so från are you saying that basically your firewall brace mounting points on the turrets have failed? That mount point bmw decided looked good was never sufficient really when you look at it, I'm hoping that since I've had the Strut brace on my car fro pretty much day one its helped minimise flex and keep these strong, i see no sort of hairline crack on my firewall brace mount points, i hope that continues to be the case but i think as these cars get older we will see more failures!

im also seen the fire wall braces themselves crack at the crush point in the middle FYI...

[Franzino]

im also seen the fire wall braces themselves crack at the crush point in the middle FYI...

If I would fit firewall braces from strong strut...do I lose the crush point? In case of an big accident is would be nice the firewall brace bend and not penetrate the dashboard (or me)...



Any opinions about the Rogue engineering race brace?

[exdos]

Problem; welding on the chassis is not legal for the yearly MOT vehicle inspection in my country... If they notice it on the inspection then it will result in a car that will be denied road access! It's true; I know about people who had this happen after the MOT inspection spotted a small aftermarket spot welding on the chassis. This resulted is a really expensive operation to get the car back to street legal....

I'm not disputing this because I've no knowledge of your laws, but how do cars in Belgium get fixed after road accidents which can be repaired but require welding?

[Beedub]

im also seen the fire wall braces themselves crack at the crush point in the middle FYI...

If I would fit firewall braces from strong strut...do I lose the crush point? In case of an big accident is would be nice the firewall brace bend and not penetrate the dashboard (or me)...



Any opinions about the Rogue engineering race brace?

the crush point appears to be gone but i can't be sure of that.

[Franzino]

Problem; welding on the chassis is not legal for the yearly MOT vehicle inspection in my country... If they notice it on the inspection then it will result in a car that will be denied road access! It's true; I know about people who had this happen after the MOT inspection spotted a small aftermarket spot welding on the chassis. This resulted is a really expensive operation to get the car back to street legal....

I'm not disputing this because I've no knowledge of your laws, but how do cars in Belgium get fixed after road accidents which can be repaired but require welding?

They replace big parts....but small spot welding on the chassis is not approved.

[Beedub]

Problem; welding on the chassis is not legal for the yearly MOT vehicle inspection in my country... If they notice it on the inspection then it will result in a car that will be denied road access! It's true; I know about people who had this happen after the MOT inspection spotted a small aftermarket spot welding on the chassis. This resulted is a really expensive operation to get the car back to street legal....

I'm not disputing this because I've no knowledge of your laws, but how do cars in Belgium get fixed after road accidents which can be repaired but require welding?

They replace big parts....but small spot welding on the chassis is not approved.

totally bizarre.

[exdos]

They replace big parts....but small spot welding on the chassis is not approved.

I don't know whether this would help you to get around that stupid legislation, but get a helpful engineering company to weld brackets onto both the removable tower suports for the OEM strutbace and also get them to make a pair of diagonal braces that fix to these points and the firewall. Simply remove the strutbrace and supports when presenting the car for MOT. Would that help?

Alternatively, discuss the problem and the potential solutions with your usual MOT tester. If they won't help find a more helpful tester.

[Franzino]

They replace big parts....but small spot welding on the chassis is not approved.

I don't know whether this would help you to get around that stupid legislation, but get a helpful engineering company to weld brackets onto both the removable tower suports for the OEM strutbace and also get them to make a pair of diagonal braces that fix to these points and the firewall. Simply remove the strutbrace and supports when presenting the car for MOT.

This is something that me and the shop are thinking about...

[Franzino]

My Bilstein suspension is now one year old… From day one it made a small rattling noise in the front
Everything was checked for hours in my garage and nothing was found loose. Then we were thinking that maybe the problem was with the connection of the firewall braces but after some more investigation every connection looked ok with zero movement. In the end I was 99% sure it had something to do with the front Bilstein shock absorbers themselves. It was only a small noise, but the suspension felt 100% ok and made my car drive better and more fun (on street and track).

This month the noise suddenly got worse and I could also feel a little movement in my steering wheel when the front suspension was taking bigger bumps. This was not good news! Next month my dealer is taking everything of the car and sending the suspension back to Bilstein… Let's hope they will fix the two problems! This means I will be driving some time with my old suspension (oem dampers with Eibach springs).



https://www.youtube.com/watch?v=BTDTWD5S4uI

[exdos]

Just a thought: in the parts diagram below, have the two bolts (numbered 3), which attach the shock absorber to the wheel hub been replaced with new bolts when the suspension was fitted? If not then that would be my first point of suspicion. BMW uses self locking bolts which lose their grip if reused and these particular bolts are on TIGHT and take some shifting to undo. Unless these bolts are gripping as tight as they should be then this will give you some rattling - ask me how I know?