Help: M technic suspension?

[reelizmpro]

I have a theory behind what has been happening since this came up before. People noticed that M3 front springs now have the same PN as 85 318i/325e springs and conclude that they have always been identical springs. This isn't true. All of those springs are different from each other. If you put M3 springs on those cars it'll lower them by about an inch. If you put 325 springs on a 318, it'll raise the 318 so high it'll look lifted, etc. What I believe is happening, is that BMW has consolidated the various springs into a single part (probably the M3 spring). So if you want to buy new springs for your 318i for some reason, you will probably get the M3 spring. I've noticed this with other BMW parts as well. If there is more than 1 version, they will supercede/consolidate them all down to one version. Then you get the part and are surprised to see that it is different but works. Examples are S14 throttle body gaskets and accelerator cables, etc. So it's not that RealOEM is wrong, it's just that BMW superceded/consolidated a lot of parts. I can't imagine them getting a lot of orders for BMW M technic rear shocks for an almost 30 year old car for $200 each when you can get the equivalent Boge Turbo Gas (or whatever they call it these days) shock for $58 each.

[E30_Pare]

I was under the assumption that boge/sachs were made by the same company.

[P.Kelly]

Reel - that could very well be the case. However, in other places BMW will simply discontinue the part, so I guess they maybe simply be inconsistent on how they deal with this stuff.

Have you found a suitable replacement strut/shock for an m-tech that has similar properties to the original?

[jeffnhiscars]

I have a theory behind what has been happening since this came up before. People noticed that M3 front springs now have the same PN as 85 318i/325e springs and conclude that they have always been identical springs. This isn't true. All of those springs are different from each other. If you put M3 springs on those cars it'll lower them by about an inch. If you put 325 springs on a 318, it'll raise the 318 so high it'll look lifted, etc. What I believe is happening, is that BMW has consolidated the various springs into a single part (probably the M3 spring). So if you want to buy new springs for your 318i for some reason, you will probably get the M3 spring. I've noticed this with other BMW parts as well. If there is more than 1 version, they will supercede/consolidate them all down to one version. Then you get the part and are surprised to see that it is different but works. Examples are S14 throttle body gaskets and accelerator cables, etc. So it's not that RealOEM is wrong, it's just that BMW superceded/consolidated a lot of parts. I can't imagine them getting a lot of orders for BMW M technic rear shocks for an almost 30 year old car for $200 each when you can get the equivalent Boge Turbo Gas (or whatever they call it these days) shock for $58 each.

This ties in with my discovery that M3 Cabrio springs (euro only) are the same PN as a 318iC. I assume this is due to the similar weight of the 4 cyl engines.

I was under the assumption that boge/sachs were made by the same company.

Boge & Sachs are both ZF subsidiaries...as is Lemfoerder

[e30leigh]

what is the drama?

isnt the only difference with the m-tech shocks the internal valves and rebounding ect due the difference in spring rates and requirement for a sportier ride?

the length and diameter is the same as non m-tech shocks from what i can find? so buying a koni sport or bilstien hd or sport should be just as good or better then a factory m-tech shock? not to mention they are cheeper and servicable.

[P.Kelly]

the length and diameter is the same as non m-tech shocks from what i can find? so buying a koni sport or bilstien hd or sport should be just as good or better then a factory m-tech shock? not to mention they are cheeper and servicable.

I'm trying confirm that the length/travel is the same. Where did you find this information?

[reelizmpro]

I'm sure the length/travel is the same. The m tech suspension wasn't dramatically lower than stock. The shocks were gas charged though.

[e30leigh]

i cant remember where ive seen what. i just remember looking through all the specs when i was shopping for shocks. i basically came the the result m tech was different internally. not size wise in anyway.

as both bilstien and koni list the vert/ m3 shocks as the same as m tech for sedan and coupe versions. it basically came down to a valve and rebound difference i think.

[jeffnhiscars]

i cant remember where ive seen what. i just remember looking through all the specs when i was shopping for shocks. i basically came the the result m tech was different internally. not size wise in anyway.

as both bilstien and koni list the vert/ m3 shocks as the same as m tech for sedan and coupe versions. it basically came down to a valve and rebound difference i think.

Bilstein usually valves their dampers for 4cyl cars differently than for 6's but if the PN's are the same then the internals will be. You can get the damping rates from:

Wes Welch
Technical Product Information Coordinator
Wes.Welch@thyssenkrupp.com

[NeverEnough02]

Lets bump this up. When I search part numbers for replacement MT2 dampers, I get Bilstien, Sachs, and BMW as OEM for the front and Sachs for OEM rear. The prices are all over the place.

Has anyone confirmed what manufacturer originally made these for BMW to put in these cars? Mine are likely original (89k miles) and they are black unlike the yellow ones pictured earlier in this thread.