Bilstein b6 with stock springs

ShaunKC · Post by **ShaunKC** » Sat Jul 22, 2023 2:06 pm

Sajk wrote: ↑Sat Jul 22, 2023 1:18 pm OK so b6 on stock springs should help with the crash bang but will raise the ride hight. What are we talking here like 2mm or 10mm.

When I was disputing the height, Bilstein sent (via Larkspeed) this information...

I’ve spoken with Eibach and their official data collected post fitment of their pro-kit during development was;

Front 348mm
Rear 358mm

These are from wheel centre to top of arch lip and also carry a +/-5mm tolerance.

My car is (as best I could measure) 364mm, so at the top end but basically within tolerance (+1mm). Eibachs are supposed to drop the car by 10mm. So on standard springs assuming the same tolerance at the rear 368mm +/-5mm

Sajk · Post by **Sajk** » Sat Jul 22, 2023 2:19 pm

Thanks. Will measure when I get home tomorrow. Assume this us from wheel center to top of gap?

99ron · Post by **99ron** » Sat Jul 22, 2023 2:51 pm

With full B12 kit mine is 356mm rear, 341mm front. Measured on flat garage floor. Front a lot lower than expected.

99ron · Post by **99ron** » Sat Jul 22, 2023 5:10 pm

Ermm. I see part number E10-20-010-04-22 for the Z4M springs. Mine seem to be 112001004HA/VA.
Have I got the right springs? Would this explain lower than expected front? Definitely ordered a Z4M B12 kit.

ShaunKC · Post by **ShaunKC** » Sat Jul 22, 2023 5:17 pm

Yes it looks like you have the right ones. Here are mine where you can see the code.

LawrenceW · Post by **LawrenceW** » Tue Jul 25, 2023 4:19 pm

Zedebee wrote: ↑Thu Jul 20, 2023 7:57 pm If your suspension is original and there are some miles on the car, best cost option is just to replace with OEM Sachs.

In the interest of sharing - I've wanted to replace my original shocks with same spec OEM Sachs but as already called out on this thread they are no longer available, albeit may still be available from BMW which I can imagine would be painful.
Anyway, after scouting around I managed to find what looks like OEM Sachs for like for like replacements, the pain is this seller is based over in the USA. He's now got 1 pair left and happy to ship to the UK......at a cost. As said, thought I'd share -

https://www.ebay.co.uk/itm/314089411204

Zedebee · Post by **Zedebee** » Tue Jul 25, 2023 4:28 pm

Apologies LawrenceW, when I wrote that I did not realise it was the “M” thread.

LawrenceW · Post by **LawrenceW** » Tue Jul 25, 2023 4:42 pm

Zedebee wrote: ↑Tue Jul 25, 2023 4:28 pm Apologies LawrenceW, when
I wrote that I did not realise it was the “M” thread.

No apology needed - you was right! As Sachs was the supplier for Z4M’s

Sajk · Post by **Sajk** » Tue Jul 25, 2023 5:29 pm

LawrenceW so you going to take the ebay ones?

LawrenceW · Post by **LawrenceW** » Tue Jul 25, 2023 5:41 pm

Sajk wrote: ↑Tue Jul 25, 2023 5:29 pm LawrenceW so you going to take the ebay ones?

Yep, there was originally 2 sets for sale, I’ve had one of the sets so there’s still 1 set left.
Btw the seller’s name is Jack and he was great sorting it out as originally he was only shipping in the USA but he’s opened it up to the UK now too

Sajk · Post by **Sajk** » Tue Jul 25, 2023 5:49 pm

@TheTJunction who has b6 and stock springs. When you get a chance could you please try measure from the center of the wheel to the bottom of the arch. I measured mine best as I could oem springs and shocks. 365mm rear 360mm front. Thanks in advance.

wyshyvanuk · Post by **wyshyvanuk** » Sun Jul 30, 2023 4:48 pm

FWIW, I believe that Birds had been recommending the stock springs and B-6 shocks combination. I tried these on my 2008 Z4M and thought the ride was excellent. The B6s MAY have increased ride height just a bit, but the OEM shocks (at 45K miles) had no pressure left at all.

Z4-forum.com

Z4-forum.com