I've read through about 8 threads concerning the Euro M springs (31332225115 front, and 33531125315 rear). There is really no clear determination of what shocks to use. I know it depends on what the owner is trying to achieve out of esthetics versus function. I want a good medium between the two.
I have read that the Bilstein sports and Bilstein HD are valved the same, but have different ride height. I have also seen that they have to be revalved to work correctly with these Euro M springs. I am assuming that you send them back to Bilstein to have this done, but what specs do you tell them to use?
Or is there a better shock that is more "off-the-shelf," in other words: doesn't need revalving to work with these springs.
I know this may be beating a dead and buried horse, but I've spent most of the evening trying to get the right answer.
Last edited by Retro Rust on May 08, 2012 2:55 PM, edited 1 time in total.
Just buy the correct set of Bilsteins from BMW to match the springs. That will be your best bet. They will come valved properly for the springs and will work correctly. The difference between the HDs and sports is not the ride height so to speak. The shocks and struts for that matter have some but not a lot of impact on ride height. The main difference is that the piston in the sports is shorter to prevent bottoming out the shock using lowering springs. Therefore it gives you move suspension travel.
Also the springs you are listing are the E28 M5 stock springs, not the M-tech springs. The M-tech springs are the stock lowering springs. The Euro M5 springs will lower a US M5, but not by a whole lot, maybe 10-15mm. Anyway here are the matching PNs for the BMW Bilsteins.
Front 31322225016
Rear 33521129241
If you search M-tech springs you should get a bunch of info posted by Chris Graff (cgraff).
I personally would go for the BMW Bilsteins with the Red M-techs. You can get specific ones for the Red springs. And honestly then you won't have the bouncing butt syndrome of the Bilstein Sports.
m535is wrote:I personally would go for the BMW Bilsteins with the Red M-techs. You can get specific ones for the Red springs. And honestly then you won't have the bouncing butt syndrome of the Bilstein Sports.
So far, Ive only found the part number for the rear shock for the Mtech springs (red/short). That is 33522225666, looks like over $250 per. You are sure that it is worth that kind of money?
If the springs are about $450 and the shocks are over $500, maybe I oughta just fix the SLS?
m535is wrote:Just buy the correct set of Bilsteins from BMW to match the springs. That will be your best bet.
This is good advice here. After looking at the damper analysis data for the Bilstein B8 and B6, the correct OEM BMW shock absorbers (Bilstein or Boge/ Sachs) are well matched and will control the frequency and ride quality of the Short Red and E28 M5 European spec coil springs.
So what springs are you looking to run on what car? Then I can help get you the correct part numbers cause what you list are only US dampers which I have never seen used before.
m535is wrote:So what springs are you looking to run on what car? Then I can help get you the correct part numbers cause what you list are only US dampers which I have never seen used before.
Im looking to use the red Mtech springs for my 88 US M5. As far as OEM BMW shocks for the red springs go, I didn't think the red springs were even meant for an M5, as I thought the M5 was several hundred pounds heavier than a 535i or M535i. But it seems that several people on this board and other boards have used the red Mtech springs on their US M5s and seem to work fine.
Ok so Chris Graff did this to the M5 he had a few years back and since I keep exceptional records I was able to look up the research and what he ended up doing.
So there are 2 M-tech front springs
2225645
2225646
Now the 646 is designed for heavier cars. Chris ended up using the 645 and found it gave him over an inch of drop in the front. It is up to you which one you want to use.
Now basically the deal is this, the Euro M5 is about 10mm lower than the US car. So if you were to put in Euro M5 springs with the correct point system you would lower the car 10mm. The M-tech springs with the correct point system would lower the car 26mm. Now the 646 is going to be correct for a US M5. The spring rate of the 646 and the 645 are the same, it is just the free length of the spring is different. This would mean if you put a 645 in the car you are probably going to get 30-33mm lower.
The correct Shocks for the 645 and 646 springs are
2225662
As for the rear springs there is actually 1 M-tech rear part number
2225654
This means you have no options in terms of the point system.
The correct Shock for the 654 is
2225666
Now in addition to all this info there is addition info for the spring pad thickness. There are 3mm thick and 9mm thick spring pads. Obviously if you are wanting to lower the car as much as possible you would use the 3mm parts. But you can use the spring pads to adjust ride height slightly.
As for the prices, you should be able to get some really good discounts on this stuff through the dealer connection on the site. I can't remember who exactly it is, but I think they give us 25% discounts. But like I said before get the BMW shocks as they are valved for the springs and the car will ride and handle well. The front Bilstein Sports will be too hard and the rears will be too soft, which means you will probably want to get them revalved which if you purchase a set of sports new and then revalve them, it will cost just as much money as it would just to buy the BMW ones from the beginning.
I will check on some prices and let you know how I come out. I need to pull the trigger on this soon if I want to have a functioning suspension for the Vintage.
Front Spring P/N: 31 33 2 225 115
Rear Spring P/N: 33 53 1 125 315
That is what this thread was originally about. These were the two part numbers that I first listed. These part numbers are NOT M-Tech springs. They are OEM Euro M5 springs. I am not trying to be anal about semantics, but on this subject the devil is in the details.
It seems that the concensus on these springs is that the OEM BMW shocks are the best match for these and those part numbers are listed above.
Front Spring P/N: 31 33 2 225 115
Rear Spring P/N: 33 53 1 125 315
That is what this thread was originally about. These were the two part numbers that I first listed. These part numbers are NOT M-Tech springs. They are OEM Euro M5 springs. I am not trying to be anal about semantics, but on this subject the devil is in the details.
It seems that the concensus on these springs is that the OEM BMW shocks are the best match for these and those part numbers are listed above.
Thanks for the clarification. Do you know if they are shorter than the stock US M5 springs? If so, how much shorter?
Aside from the OEM BMW shocks, is there a next best shock for these springs? It seems that I need the same answer as you do. Sorry for cluttering your thread.
Last edited by L_N_Love on May 09, 2012 10:13 AM, edited 1 time in total.
Front Spring P/N: 31 33 2 225 115
Rear Spring P/N: 33 53 1 125 315
That is what this thread was originally about. These were the two part numbers that I first listed. These part numbers are NOT M-Tech springs. They are OEM Euro M5 springs. I am not trying to be anal about semantics, but on this subject the devil is in the details.
It seems that the concensus on these springs is that the OEM BMW shocks are the best match for these and those part numbers are listed above.
Thanks for the clarification. Do you know if they are shorter than the stock US M5 springs? If so, how much shorter?
Aside from the OEM BMW shocks, is there a next best shock for these springs? Please excuse my ignorance on the subject.
Well I have looked through a lot of threads and I decided that I wanted about a 1 inch drop, so the Mtechs that I listed above had a lot of positive things said about them, so that is what I went with. The Euro M springs will lower a US M5 about 10-15mm. The M-techs that I ordered will lower it about 26mm. Many people on this board have said that you have to have the right valving on the shocks that you match with the springs or else they will be bouncy or bottom out etc. I decided that BMW OEM shocks to match the BMW springs is the best idea. I have seen in several posts that people have used off-the-shelf bilsteins, some have had them revalved, some not. I think you will be taking your chances of having some strange ride qualities if you go with a off-the-shelf Bilstein. By no means, am I an expert, I have just been reading tons of threads recently. Most of what I have read has been opinions, so you just have to align yourself with someone else who has a philosophy similar to yours. I wanted a slight drop with a mostly civil ride, so according to what I read, the Mtech springs with the matching OEM shocks were what I went with. Read M535i's responses above, he gave some really good info. Make sure you get the right Mtech, as there were several different part numbers floating around. Also in my choosing the Mtech springs/shocks, I am trying to avoid changing any of the stock suspension settings (ie custom camber plates etc), we will see if I am successful with this.
Couple of things. If you are going to use the Euro M5 springs then you should use the matching Euro M5 dampers. If you are dead set on not using the matching BMW parts I would use the Spax as the adjustment will allow you to tune it to your liking.
Retro is correct, as I said in my earlier post using the Euro M5 springs on a US M5 will lower it about 10mm.
Do you want the PNs for the matching Euro Dampers?
Rob...No, but thanks for the offer of the PNs. I thought the spring #s I had were the MTechs. This thread has saved me from ordering the wrong springs. I am going to hold off a little while and see what Retro thinks of his setup.
Chris, Do you by chance have a picture or physical description of the euro M5 springs? I had the front apart 2 weeks ago and I could have sworn a read an eibach label on the spring. I didn't pay much attention to it at the time, but it peaked my interest again last week, but I couldn't see any writings on the spring with just a flashlight.
The only markings I could find on the rear springs were blue dots on each coil
Do you want the PNs for the matching Euro Dampers?
Rob, could you post the Euro damper PN's here - just to build as much of a reference thread as possible. Or are they some the PN's shown in your post above?
Chris, Do you by chance have a picture or physical description of the euro M5 springs? I had the front apart 2 weeks ago and I could have sworn a read an eibach label on the spring. I didn't pay much attention to it at the time, but it peaked my interest again last week, but I couldn't see any writings on the spring with just a flashlight.
The only markings I could find on the rear springs were blue dots on each coil
Eric,
I'm 99.99% sure I installed the M-tech spring in the front of your car. It should be in the records I gave you with the car.
