What are ZCP springs marked "X8"?

I just picked up some used ZCP suspension parts in hopes of raising my 2011 M3 back up to stockish heights. I have a non-ZCP car but was happy to find ZCP springs thinking that they should raise up my H&R lowered car, but keep it slightly lower than a stock non-ZCP car.

I took the ZCP springs off the struts they came on yesterday. My plan is to install them on my struts with 60k on them instead of the 90k on the used ZCP parts I bought. I was expecting them to be all factory. What I found was that the strut guides have been shaved, springs are marked X8, and E36 M3 bump stops are installed.

Anyone have any idea what might have happened to these? Previous owner thought they were stock.

What ride height could I expect with these X8 springs? Are they even ZCP? I googled it and didn't find much.

Thanks in advance.

Believe that's the heaviest-spec (DCT, Sunroof, etc. options) E90 ZCP front spring. There is a spring code thread on here. Generally a higher number means a slightly stiffer spring rate but not enough to impact ride height much.

My ZCP spring set is X6 front X5 rear. OEM non-ZCP springs on coupes and sedans are either X1, X2, or X3 IIRC, depending on spec.

What is the code on the rear springs? Painted-on rather than tagged.

1M springs start with a Y.

I will check rear springs tonight. I just grabbed the front and took it with me to work.

What do you suppose is up with the E36M bump stops and shaved guides?

My car has the sunroof and some options so it might be a good fit even though it won't make too much of a difference. The constant "Increased Emission" code weighs on me heavily so that might balance it out....

Thanks for you input!

Rob

Another Q:

Will the ZCP struts work fine in my Non-ZCP EDC car? Providing the ZCP struts work correctly of course. Meaning, if they work correctly, my car will recognize them and not throw codes and they will still function?

The struts are the same between ZCP and non-ZCP. Difference is in the EDC module coding.

Richbot wrote

Believe that's the heaviest-spec (DCT, Sunroof, etc. options) E90 ZCP front spring. There is a spring code thread on here. Generally a higher number means a slightly stiffer spring rate but not enough to impact ride height much.

My ZCP spring set is X6 front X5 rear. OEM non-ZCP springs on coupes and sedans are either X1, X2, or X3 IIRC, depending on spec.

What is the code on the rear springs? Painted-on rather than tagged.

1M springs start with a Y.

Rears are painted X6 M3.

Couldn't find it right away but as mentioned there is a thread here but also on M3cutters.com created by Alpina527 when he retrofitted ZCP on his car. Find it, tons of spring and shock details.

Thanks. Im actually in the process of swapping the ZCP springs onto my dampers but my dampers are corroded and won't come apart. I don't want to install the ZCP dampers because they have 85k on them. Putting it back the way it was....

Shameless plug.


OE ZCP Suspension Info https://www.m3post.com/forums/showthread.php?t=1481852

Thanks for the link Derbo. Lots of very informative reading there.

I did finally figure out how to get my H&R springs off. Someone over torqued the shaft nut and the 10mm shaft hex was stripped really badly. After soaking in PB Blaster for a week and a little coaxing it came off.

I installed the X8 up front and the X6 in the rear. My car is heavily optioned. Aside from the lighter 6MT, I think these springs are a perfect match. Higher than the H&Rs and lower than stock non ZCP but rides really good and I can drive down city streets without fear.

This is all that I wanted. I'm happy.

Captain Starbucks wrote

I installed the X8 up front and the X6 in the rear. My car is heavily optioned. Aside from the lighter 6MT, I think these springs are a perfect match. Higher than the H&Rs and lower than stock non ZCP but rides really good and I can drive down city streets without fear.

This is all that I wanted. I'm happy.

This sounds excellent, Captain. Bought my E90 a couple months ago with H&R sports already installed and I cringe when I have drive into downtown. Hope to get the same stock ZCP springs back on soon.

Did you have to replace any other shock/spring components? Thinking it would be a good idea to replace bump stops and strut mounts at 76k miles.

All of my stuff was in pretty good shape so I just reused it all. Make sure you have a tub of grease on hand to repack the mount bearings. They disassemble and reassemble very easily. Minimal grease from factory. I have 60k.

Let me know how it turns out.