The reason why B4's are considerable cheaper is that they are twin tube design, both the B6 + B8's are mono tube design which are far superior.JINGLE said:hopz121 said:B4's are equivalent to OEM, (even M Sport)
B6's are Uprated over OEM
B8's are Uprated even more over OEM and suitable for matched lowering springs.
All of the above shocks are better than the M sport shocks you are replacing, B4's are a perfect OEM alternative
that being said i will order some B4s and have them fitted this weekend!!
M sport replacement rear shock or aftermarket?
- Thread starter JINGLE
- Start date
Hi. Interested in hearing how the B4's feel once fitted. I am looking to replace all four shocks and have the factory M sport package. I have driven myself crazy in the research I have carried out on this. First stop is that a full set of the Sachs/Boge OEM can be found on Ebay for about £260-£270 but is for the standard suspension car (incidentally, about £100 less on German ebay-delivered to UK), Sachs codes are 312466 and 312467 fronts and 312468 rear. The Advantage Sachs for M-sport suspension is absolutely impossible to find in the UK and I have been told by a German contact that Sachs no longer manufacture them. To bear this up, a call to my local BMW dealer for prices on a full shock absorber kit for Z4 E85 M-sport shock absorber set produced the reply, "that will be £880 incl vat", gulp! Could it be that someone like Bilstein is supplying B8's to BMW? Bilstein recommend only the B8 for M-sport Zeds but advertise B4's and B6's as ok for a certain amount of lowering (30-40mm), whats that all about then? I spoke to Bilstein technical Dept and got a seemingly very knowledgeable guy who said, of course B4's will fit the Z4 M sport suspension but the suspension will be degraded as the B4 is not recommended. Will it though, and has it ever been tried? We are only talking 15mm drop on the M-sport. On a personal note, I am not bothered about a slight drop in handling if it means I will get a more comfortable ride, as long as the car is still completely stable and planted at higher speeds. I am concerned that B8's will give an even harder ride than the M-sport OEM Sachs. As Jingle has taken the plunge and purchased the B4's I will be very keen to hear the outcome. The Bilstein technical guy stated that B6 and B8 are identical in valveing and the real difference is that the B8 is shorter to match lowered suspension. If that's the case, why is the B8 much more expensive when all they have done is cut a bit off the strut rod? He also said that by using the slightly (15-20mm?) longer B6 or B4 with lowered suspension it will mean the shock absorber piston is under constant compression even when the car is standing, due to the longer stroke shocks, which could promote early failure, the reason why they do not recommend them for the Z4 M-sport! Why then, do they say they are ok for up to 40mm lowering in their advertising? Are you confused yet, because I am!
If you have an M-sport suspension Z4, it is an absolute minefield if you need new shock absorbers, with such a limited amount of information. Shame on you BMW for such a rip off. If they are now Bilstein re-badged BMW, I have been offered a brand new full set of B8's delivered to the UK from a large German motorsports supplier for £428, and they are still making a profit. The B8's are correct for my car but I am really worried about an increase in the hard(ish) ride I already have from the M-sport suspension. If anyone is riding on B8's with the sports suspension on their Z4, I would really appreciate some feedback.
Finally, I have sourced these in Denmark, http://www.schmiedmann.co.uk/Z_series/Z4_E85/Spare_parts_brakes-chassi-suspenssion_etc/Shock_absorbers-springs_and_accessories.htm which they say are shortened and for lowered Z4's(click on 'show details' under the photo). They are only £300 for a full set plus dust boots, new spring base rubbers etc, delivered to the UK. The problem is, how good are they? A search has shown some promising reviews, shame about the name 'Lowtec', doesn't conjure up a quality product. Iv'e emailed to ask for more specification and quality details and will report once I get a reply. Just might be the solution for all of us M-sport owners, at last.
If you have an M-sport suspension Z4, it is an absolute minefield if you need new shock absorbers, with such a limited amount of information. Shame on you BMW for such a rip off. If they are now Bilstein re-badged BMW, I have been offered a brand new full set of B8's delivered to the UK from a large German motorsports supplier for £428, and they are still making a profit. The B8's are correct for my car but I am really worried about an increase in the hard(ish) ride I already have from the M-sport suspension. If anyone is riding on B8's with the sports suspension on their Z4, I would really appreciate some feedback.
Finally, I have sourced these in Denmark, http://www.schmiedmann.co.uk/Z_series/Z4_E85/Spare_parts_brakes-chassi-suspenssion_etc/Shock_absorbers-springs_and_accessories.htm which they say are shortened and for lowered Z4's(click on 'show details' under the photo). They are only £300 for a full set plus dust boots, new spring base rubbers etc, delivered to the UK. The problem is, how good are they? A search has shown some promising reviews, shame about the name 'Lowtec', doesn't conjure up a quality product. Iv'e emailed to ask for more specification and quality details and will report once I get a reply. Just might be the solution for all of us M-sport owners, at last.
Glad I wasn't the only person confused looking into it (thought I was either stupid, or there was just not a lot of info out there..... Which as u confirm? There isn't!)
I spoke to bilstein direct also and they confirmed they would only suggest b8 due to it being lowered etc but like u said about the B4 also state they can be used.... So I took the plunge and went for a set of rear B4s (about £120 from memory) and a set of Meyle HD top mounts.
Good job I changed as the passenger side top mount had "popped" completely out and both shocks were broke and didn't spring back out after compression by hand.
Still early yet as I've only driven home on them but feel absolutely fine so far and fitted etc near indenticle so shouldn't see a problem, will keep u updated of any issues that may arise and if I noticed any difference in ride quality
I spoke to bilstein direct also and they confirmed they would only suggest b8 due to it being lowered etc but like u said about the B4 also state they can be used.... So I took the plunge and went for a set of rear B4s (about £120 from memory) and a set of Meyle HD top mounts.
Good job I changed as the passenger side top mount had "popped" completely out and both shocks were broke and didn't spring back out after compression by hand.
Still early yet as I've only driven home on them but feel absolutely fine so far and fitted etc near indenticle so shouldn't see a problem, will keep u updated of any issues that may arise and if I noticed any difference in ride quality
Thanks, look forward to any good news. I strongly suspect that they will be absolutely fine, will perform exactly as the oem ones did and, as they are new, will definitely perform better than old shocks that have been in use for many years and tens of thousands of miles.
There are conflicting opinions/views out there if the B4s are an optimal fit for cars with M sport springs sadly.
In my case, the original Sachs-branded M sport absorbers (front and rear) were leaking badly:
Condition of an absorber that is way past its prime:
Where I am located, I could not find original M sport absorber replacements except for Boge-branded absorbers meant for non-M sport springs.
Front:
Rear:
I swapped those in since new absorbers are for sure better than leaky, blown units. Now it's a question on how long these can last with the stiffer and lower M sport springs...So far ride quality and handling is miles better than before but whether it is optimal, who knows? :roll:
In my case, the original Sachs-branded M sport absorbers (front and rear) were leaking badly:
Condition of an absorber that is way past its prime:
Where I am located, I could not find original M sport absorber replacements except for Boge-branded absorbers meant for non-M sport springs.
Front:
Rear:
I swapped those in since new absorbers are for sure better than leaky, blown units. Now it's a question on how long these can last with the stiffer and lower M sport springs...So far ride quality and handling is miles better than before but whether it is optimal, who knows? :roll:
The B8 shock is shorter than standard so suits lowered cars, isn't M tech 15mm lower than standard? so it might be the M tech shocks are shorter to suit, without seeing them side by side or getting the dimensions this is a bit of an enigma?
I would be surprised if it did, after all the bump stop is there to prevent the springs going coil bound or the dampers bottoming, I can see how the shorter shock may be required if your lowering the car, simply to prevent the shorter spring coming loose on full suspension droop.
I run B4's on my M3 and they are far superior to the standard sanchs item it replaced and apparently they are better made too.
If they sell the B4 for the M3 I'm sure my theory and research was correct that they are perfect for M Sport suspension.
B4's are very highly rated on the M3cutters form too, some even prefer them to the B6 offerings.
If they sell the B4 for the M3 I'm sure my theory and research was correct that they are perfect for M Sport suspension.
B4's are very highly rated on the M3cutters form too, some even prefer them to the B6 offerings.
OMG! Such a minefield. The VIN report on my 2003 2.5i E85 94k says that it has M sports suspension. I can see a set of 4 B4s for £199 on eBay but the site says they won't fit my car and I certainly don't want it any lower as I hit every bump going as it is. But autodoc says B4s are ok but charge around £100 per front shock.
I don't need anything special, just want to improve the ride. Also, do I need to replace the springs as well? All advice would be much appreciated.
I don't need anything special, just want to improve the ride. Also, do I need to replace the springs as well? All advice would be much appreciated.
The shocks don't control the ride height, its the springs that do that. I have B4's all round on my Mpsort car and they are great. £199 seems very cheap!
Bilstein 4x B4 Shock Absorbers Dampers Set High OEM Quality 19-109572 22-105813 | eBay UK
Bilstein B4 Shock Absorber. Bilstein B4 benefits at a glance The Shock Absorbers you receive may differ in appearance. These cars will normally require different shock absorbers. Bundle Contents.
ebay.us
This is the link. Are B4s all the same or could the be car-specific because the site says they are not compatible with my car?
They are car specific for a multitude of reasons, eye hole diameter, length, damping rate etc and for the struts there are the position of the various brackets to fit drop links, height and size of the spring platform, locations for brake pipe retaining clips and so on.
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Eindhoven NL
B4 shocks compatible with the E85 have part number 19-158983 for the rears. They aren't left or right specific so you can just purchase two that match that part number.Bilstein 4x B4 Shock Absorbers Dampers Set High OEM Quality 19-109572 22-105813 | eBay UK
Bilstein B4 Shock Absorber. Bilstein B4 benefits at a glance The Shock Absorbers you receive may differ in appearance. These cars will normally require different shock absorbers. Bundle Contents.ebay.us
This is the link. Are B4s all the same or could the be car-specific because the site says they are not compatible with my car?
Front left: 22-164568
Front right: 22-164575
I installed B4's for my msport setup due to comfort. Read that B6's are a bit too stiff in terms of ride quality. Done 1000km's and they work great