"Edition" M3 Suspension Discussion

[Ant Man]

Heard back from Sytner today. Technical Division at BMW AG will not provide the information we seek on the Edition suspension. However my dealer can order rear Edition springs but the computer currently says 'no' (anybody watch Little Britain?) as nobody has ordered any yet. I expect this to change shortly. Based on the price of the rears, the cost of all 4 (in the UK) will be 30% dearer than Eibach.

Also dealer can order all the other dark chrome goodies, wheels etc.

[aajami]

Originally Posted by Ant Man

Heard back from Sytner today. Technical Division at BMW AG will not provide the information we seek on the Edition suspension. However my dealer can order rear Edition springs but the computer currently says 'no' (anybody watch Little Britain?) as nobody has ordered any yet. I expect this to change shortly. Based on the price of the rears, the cost of all 4 (in the UK) will be 30% dearer than Eibach.

Also dealer can order all the other dark chrome goodies, wheels etc.

Thanks for following up on this, Ant Man. By the "information we seek", are they referring to the part numbers for the shocks? I don't know if I'd want to order Edition springs without knowing if and how the shocks are different from ours.

If the dealer can check "the computer" for springs, can he also do the same for shocks?

[Ant Man]

Originally Posted by aajami

Thanks for following up on this, Ant Man. By the "information we seek", are they referring to the part numbers for the shocks? I don't know if I'd want to order Edition springs without knowing if and how the shocks are different from ours.

If the dealer can check "the computer" for springs, can he also do the same for shocks?

They would not confirm if the Edition models had different EDC shocks, software or any other suspension changes apart from shorter springs.
I took some pictures on my phone of Edition front strut and standard M3, if anything apart from springs looks different, I'll post it up.

From personal experience watching my dealer, the BMW system is not user-friendly at all for finding parts on certain items. I can ask about the shocks.

[alpina527]

The Edition uses shorter shocks, but uses the same springs as the normal M3 depending on spec. Top mounts and bump stops are also the same.

There are around 6 different springs available for the E92 depending on the spec of the car

[BaLLzZz]

Originally Posted by alpina527

The Edition uses shorter shocks, but uses the same springs as the normal M3 depending on spec. Top mounts and bump stops are also the same.

There are around 6 different springs available for the E92 depending on the spec of the car

Can you elaborate in detail?

[aajami]

Originally Posted by BaLLzZz

Can you elaborate in detail?

BMW uses different springs (I didn't know there were six until alpina527's post) because an M3's weight varies from one car to the other, depending on how it was optioned out. A bone stock M3 weighs significantly less than a fully optioned M3. That's why if you check realoem.com or bmwparts.info for spring PNs, you won't find any. Your dealer would need your VIN in order to determine which springs your car has.

That's a very nice find, alpina527. Mind if I ask how you got that info?

[aajami]

Originally Posted by alpina527

The Edition uses shorter shocks, but uses the same springs as the normal M3 depending on spec. Top mounts and bump stops are also the same.

There are around 6 different springs available for the E92 depending on the spec of the car

Seriously? The springs are the same but it's the shocks that are different? That doesn't invalidate the findings that some members discovered about the Japanese M3's lower suspension. The shocks were different from US and European M3s, but they were unable to determine differences in springs (likely for the reason I mention in the post above).

How very interesting...

[BaLLzZz]

Originally Posted by aajami

BMW uses different springs (I didn't know there were six until alpina527's post) because an M3's weight varies from one car to the other, depending on how it was optioned out. A bone stock M3 weighs significantly less than a fully optioned M3. That's why if you check realoem.com or bmwparts.info for spring PNs, you won't find any. Your dealer would need your VIN in order to determine which springs your car has.

That's a very nice find, alpina527. Mind if I ask how you got that info?

Haaa I knew that information but thank you. I was saying elaborate in the exact SIX variations with PN's etc so that we can all do our due diligence etc etc

[Ant Man]

Originally Posted by aajami

Seriously? The springs are the same but it's the shocks that are different? That doesn't invalidate the findings that some members discovered about the Japanese M3's lower suspension. The shocks were different from US and European M3s, but they were unable to determine differences in springs (likely for the reason I mention in the post above).

How very interesting...

Realoem supports the shorter strut explanation too.

[JAJ]

Originally Posted by aajami
Seriously? The springs are the same but it's the shocks that are different? That doesn't invalidate the findings that some members discovered about the Japanese M3's lower suspension. The shocks were different from US and European M3s, but they were unable to determine differences in springs (likely for the reason I mention in the post above).

How very interesting...

The springs vary in rate depending on how heavy the car is after it's built with the factory options. Cars without air conditioning, power seats, etc will be lighter than cars with a full load. So, to keep the lighter cars from sitting higher (they don't like that "lift-kit look" either) BMW uses different springs (usually marked with a colored stripe). That way, they ensure that every car they build rolls out the factory door within the specified range of ride heights for the model.

They don't change springs to affect performance, or to modify the car's stance. The factory's "job" is to build the car exactly to spec for ground clearance for the market in which the vehicle is homologated. To do otherwise would invite lawsuits if anything goes wrong.

So, what happens when "the factory" lowers the car?

The "factory" that builds the car doesn't do anything. A change-order goes to Engineering, and they engineer a complete component solution so that when the lowered car is finished it rides within a new specified range of ground clearance measurements. It comes complete with new specs for any parts that must change to deliver that ground clearance spec while maintaining vehicle safety and performance.

Most likely in the BMW "Edition" case, and with absolute certainty in the Japanese market case, BMW uses different struts on the lower-riding cars. It's likely that they moved the spring seats to lower the car, but you can't know for sure without measuring. They may also have specified different springs. There's just no way to know unless you have the parts right there and the tools to do the measurements.

[aajami]

Originally Posted by JAJ

Most likely in the BMW "Edition" case, and with absolute certainty in the Japanese market case, BMW uses different struts on the lower-riding cars. It's likely that they moved the spring seats to lower the car, but you can't know for sure without measuring. They may also have specified different springs. There's just no way to know unless you have the parts right there and the tools to do the measurements.

What would one need to measure? I know two people with Japanese E92s, and one of them is very technical and can probably do this for us.

[alpina527]

Originally Posted by aajami

What would one need to measure? I know two people with Japanese E92s, and one of them is very technical and can probably do this for us.

That would be very useful

Does the car have Edc, Dct, sun roof, hi fi, nav?

It would be interesting to know the wire diameter of the japanese cars coils. Every different spring grade is usually .2mm (.008") different. This can be measured with a vernier caliper or micrometer.

The spring seat height can be measured with a tape measure from the spring cup downwards to a specific bolt etc. If he can take a photo of the bolt he is measuring it to, we can then compare different strut measurements.

The japanese cars use the same bump stops and top mounts as the regular M3, so I assume the gap between the top of the bump stop to the top mount is the same at .875"

[rzm3]

Does anyone have info on the rear suspension? The ride height should be independent of the shocks because it is not a strut design.

[aajami]

Originally Posted by alpina527

That would be very useful

Does the car have Edc, Dct, sun roof, hi fi, nav?

It would be interesting to know the wire diameter of the japanese cars coils. Every different spring grade is usually .2mm (.008") different. This can be measured with a vernier caliper or micrometer.

The spring seat height can be measured with a tape measure from the spring cup downwards to a specific bolt etc. If he can take a photo of the bolt he is measuring it to, we can then compare different strut measurements.

The japanese cars use the same bump stops and top mounts as the regular M3, so I assume the gap between the top of the bump stop to the top mount is the same at .875"

I asked. We'll see what happens. Did you ever get more information from your contact at BMW about the specifics surrounding the Edition suspension?

[Ant Man]

Originally Posted by aajami

I asked. We'll see what happens. Did you ever get more information from your contact at BMW about the specifics surrounding the Edition suspension?

That's was me you asked. I've gone back with the new info we have re the struts. Hope to hear something this week.

It would be great if someone can dyno the shorter E36 bumpstops so we would have a factual account of how they compare to E92.

[aajami]

Originally Posted by Ant Man

That's was me you asked. I've gone back with the new info we have re the struts. Hope to hear something this week.

It would be great if someone can dyno the shorter E36 bumpstops so we would have a factual account of how they compare to E92.

I asked alpina527 too, as he has a BMW contact as well I've been asking a lot of people