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Bilstein Suspension. B4, B6, B8, B12.

2003 - 2009, roadster, coupe, facelift
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kis
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Bilstein Suspension. B4, B6, B8, B12.

Post by kis » Fri Jun 15, 2018 10:05 am

Some interesting reading guys. Thanks for the updates. I think I've got my head round it all now! :D

Ducklakeview do you feel the car is much more stiff and harsh now (planted and good handling aside)? Not sure what sort of roads you have? But everytime I go over a unavoidable pot hole I cringe slightly as I know it comes with a bit of a bang. My shocks will definitely be tired but trying to decide if the B8/B12 combo will be a bit too unforgiving, factoring in our fairly poor road conditions / maintenance programs.

At the moment I'm thinking that my OEM shocks will be worse than the B8 shocks. So even if I fit the B8's there will be an improvement?
My E85 Z4 3.0i SMG

BMW Family History (past and present):
1 Series - E87
3 Series - E46 Coupe, E46 M3, E90 (x3)
4 Series - F36, F82 M4
5 Series - E34 (x2), E39
7 Series - E32
X5 - E53, E70
X6 - E71

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ph001
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Bilstein Suspension. B4, B6, B8, B12.

Post by ph001 » Fri Jun 15, 2018 11:50 am

There's some pretty good guidelines that might help you identify your knocking issue Ben:

1) Knocking from worn drop links will nearly always go away as you go around a corner. This is because the body roll 'loads up' the anti-roll bars and hence puts tension/compression on the drop link and stops the knocking.

2) Knocking caused by worn tie rod ends (or track rod ends if you like) tends to be heard as you waggle the steering from side to side when stationery. Almost feels like the steering rack mounting bolts are loose. If you get someone to waggle the steering while you feel the road wheel, you can feel the 'knock' transmitted to the road wheel quite easily with worn tie rod ends.

3) Easy check for the wheel bearings is to see if there is any play in the wheel when holding it at 6 o'clock (jacked up with wheel off the ground).

Suspension bushes etc usually need a crowbar to apply pressure (leverage) to show up any movement. Of course there is also the loose strut brace bolts to check too (need to torque them to proper setting).

Kis - I would not be thinking of fitting anything other than B4 shocks to go with suplex springs if you want the ride to be at least as foregiving as oem.
Last edited by ph001 on Fri Jun 15, 2018 12:01 pm, edited 2 times in total.
2007 E85 Z4 3.0Si manual :driving:
19" CSL's | Eibach Springs | Aeroskirts | Z4M front bumper | Clear brake light | ZHP | RCH+| Stubby

2004 E46 M3 coupe manual - gone but not forgotten.

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Clarkie
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Bilstein Suspension. B4, B6, B8, B12.

Post by Clarkie » Fri Jun 15, 2018 11:59 am

Boy - am I confused. If B6 is an uprated B4 and B4 can take a either an SE or msport spring - why cant B6 also take an Msport spring?

FWIW - I am about to put B6s on with an msport spring - just wondering if that is a huge mistake
SOLD 2007 Z4 Coupe 3.0si Sport Montego Blue/Pearl Grey

mjennings23
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Bilstein Suspension. B4, B6, B8, B12.

Post by mjennings23 » Fri Jun 15, 2018 12:05 pm

Clarkie wrote: Fri Jun 15, 2018 11:59 am Boy - am I confused. If B6 is an uprated B4 and B4 can take a either an SE or msport spring - why cant B6 also take an Msport spring?

FWIW - I am about to put B6s on with an msport spring - just wondering if that is a huge mistake
The B6 will work fine with sport springs, but it will be firmer than the factory Sachs shocks.

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MACK
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Bilstein Suspension. B4, B6, B8, B12.

Post by MACK » Fri Jun 15, 2018 12:21 pm

mjennings23 wrote: Fri Jun 15, 2018 12:05 pm
Clarkie wrote: Fri Jun 15, 2018 11:59 am Boy - am I confused. If B6 is an uprated B4 and B4 can take a either an SE or msport spring - why cant B6 also take an Msport spring?

FWIW - I am about to put B6s on with an msport spring - just wondering if that is a huge mistake
The B6 will work fine with sport springs, but it will be firmer than the factory Sachs shocks.
The shorter rod of a b8 would be the better choice with m sport springs. Other than the rod length the b8 and b6 are identical
Silver 05 3.0i SE
Mods inc - F/L Xenons Clear Ind Rear Lights M Sport Seats & Wheel Eibach/B4 3.64 DIFF (SOLD)

White E89 20i M Sport
Mods inc- B12 kit, M3 Arms, 18" Zito 935's with PS4's, Decat & Remap, Switchable Exhaust Flap (SOLD)

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kis
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Bilstein Suspension. B4, B6, B8, B12.

Post by kis » Fri Jun 15, 2018 1:17 pm

ph001 wrote: Fri Jun 15, 2018 11:50 am Kis - I would not be thinking of fitting anything other than B4 shocks to go with suplex springs if you want the ride to be at least as foregiving as oem.
Really? Even given that my current shocks are? Give or take, 15 years old?
My E85 Z4 3.0i SMG

BMW Family History (past and present):
1 Series - E87
3 Series - E46 Coupe, E46 M3, E90 (x3)
4 Series - F36, F82 M4
5 Series - E34 (x2), E39
7 Series - E32
X5 - E53, E70
X6 - E71

highway1
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Bilstein Suspension. B4, B6, B8, B12.

Post by highway1 » Sat Jun 16, 2018 6:06 pm

My original (SE) dampers on my Coupe, were knackered at 62,000 (9 years old)- in fact the front o/s damper had no damping left in it whats so ever.


I decided to replace all the springs and dampers with m-sport equivalent Suplex springs and Bilstein B4- these are considered a slight improvement over standard dampers.

I didn't want the B12 kit as for one, it might be better on track but, on bumpy british roads and a quick blast across Exmoor, the better compliancy with the B4 will mean you're not pitched and thrown about as much as the B12 kit- and ultimately that little bit quicker and not so much hard work!

Also B12 kit too low for me with the garage and steep entrance/exit from car parks, local speed bumps, etc!


I also replaced all top mounts, drop-links, poly bushed the f&r anti-roll bars, and crucially a proper all-round alignment by someone who knows what they're doing!


All this made the car feel night & day difference for the better!

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