Looking for Z4 M Suspension overhaul advice

[baris41]

Hi everyone,

I've been a Z4m owner for 3 years now, and decided to keep it for long run. I only put around 3k km every year but I'm willing to start spending money on it and want to tackle front suspension first.
Car is at 107k km and dont have much info about it's past, but the front of the car feels a bit floaty and not planted, also has vibration on steering wheel starting from 120km/s.
I don't have much friends in the city I live and don't trust the mechanics, being a foreigner, people always tend to rip you off. So I need it come up with a game plan. I appreciate if you can help me with the shopping list.

- I'm planning to start buying Ball joints, Control Arm Bushings, Tie Rods, wheel bearings, rear trailing arm bushings. Polyurethane or rubber? Which other other rubber based suspension parts do I need to replace? Which brands would you recommend? Which other parts do I need to address?

- I'm thinking Bilstein B6 Struts and Shocks, do you think I need to refresh springs at this point as well? Would Bilsteins be compitable with OE springs? Which other rubber or plate do I need to change?

- Car came with spare Hamburg Technic rubber tranmission and engine mount, read mixed reviews, should I use them or upgrade them?

- How about subframe bushings? Do I need to change them at this point as well?

P.s. Wheels will be inspected and balanced and new tires will be installed.

I know it's a lot of questions to answer but, I appreciate any help. Thank you all in advance.

 

[Sajk]

I have b6 with all stock new rubber bushes. B6 is fine with oem springs. For me it's a good set up. Spirited street driving usually on weekends with the occasional trip to work. At speed it handles bumps and the like very well but can be crashy at low speed.

Handling wise the car had more talent than i do so its good enough.

As for the hardware parts you will need to find somebody to check them for you. I don't know where you live but a roadworthy or equivalent test usually is a good way to find out what needs to be replaced. I am at 82k kilos and no hard parts have needed changing apart from struts and shocks.

My advice would be to avoid poly bushes as they do transfer noise and harshness. A possible exception would be the lollypop bushes which I am considering to try to get more steering feel. I have new oem rubber in there at the moment. It's just my opinion. Others swear by poly and my only experience is that I have poly rear beam bushes in my z3 which transfer a ton of road and diff noise to the cabin that was not there with rubber. Luckily you can't hear I with the top down. Good luck.