POLL Bilstein B4 vs Bilstein B12

[the Nefyn cat]

Due to the way the suspension works fitting a 10mm pad will lift the car somewhere around 20mm, and if your beam bushes are knackered that'll influence things, too. It ain't meant to be easy.

 

[Antm72]

Good info. So if I went Bilstein Pro Kit with the -30mm springs and added 10mm spring pads, that might be about right for the pothole roads? Would it be the same size pads all around and where is the best place to get them from?

You can only really spring pad up the rear but -30 isn't too low, the frontonly really carries the engine weight so little movement adding weight.The rear will alterwith two people and a boot full so adding spring pads in the rear will improve things.
Bmw are as cheap if not cheaper than most places they are not expensive.
As posted above you add the pad at the midway point on the arm so the actual lift you get is greater than the pad you put in, i would lower it and see what if anything you need to do.
Mines -40 and i have only caught it once or twice and its not bottomed out its more that if its a sharp bump the suspension travel back down creates a bounce so driving carefully helps

 

[inkey$]

Due to the way the suspension works fitting a 10mm pad will lift the car somewhere around 20mm, and if your beam bushes are knackered that'll influence things, too. It ain't meant to be easy.

Thanks. I’m also replacing all bushes.

 

[inkey$]

You can only really spring pad up the rear but -30 isn't too low, the frontonly really carries the engine weight so little movement adding weight.The rear will alterwith two people and a boot full so adding spring pads in the rear will improve things.
Bmw are as cheap if not cheaper than most places they are not expensive.
As posted above you add the pad at the midway point on the arm so the actual lift you get is greater than the pad you put in, i would lower it and see what if anything you need to do.
Mines -40 and i have only caught it once or twice and its not bottomed out its more that if its a sharp bump the suspension travel back down creates a bounce so driving carefully helps

Got it. Thanks again!

 

[inkey$]

Just updating this thread in case anybody is looking to do similar. Eventually went with Bilstein B4 shocks, Eibach Pro -30mm springs, new 10mm spring pads and 10mm spacers for the rear - plus new ARB and control arm bushes.

For me it’s definitely the way to get a better look and better handling without sacrificing ride quality or clearance.

BEFORE


AFTER

 

[Martin Sullivan]

inkey$ now that it’s been several months how are you getting on with your setup?
What was your total cost in the end if you don’t mind me asking.
I’m considering doing exactly the same as you and have the same original mindset
Thanks

 

[kanedandunable]

anybody know what is the thread size on the top mount of the bilstien b12 pro kit 10mm or 12mm?

 

[kanedandunable]

anybody know what is the thread size on the top mount of the bilstien b12 pro kit 10mm or 12mm?

i got a response from bilstien it is 10mm

 

[Andyboy]

B4's are just standard replacements. They're nothing special and are meant for standard springs, not shorter ones. The extended length of the chrome damper rod is important. If it's too long for the shorter springs then the springs won't require much - if any - compression to fit. That's bad news as the static spring tension will be non existent and the thing will be hitting the bump stops. M Technic bump stops are also shorter for this reason.
Short springs need short damper rods so that the springs require compressing fully to fit. Coil springs are rising rate so the more you compress them, the stiffer they become. They need a certain amount of pre tension when the car sat on its wheels.
Eibach stuff is OK but H&R springs are better. Genuine BMW stuff is of course better still but are £££££. Boge Super Touring dampers are excellent as well. Just avoid Spax at all costs.

 

[Katita]

Sorry. wrong space.