Just finished ZCP retrofit

[aajami]

For anyone who frequents the suspension subforums, it will come as no surprise that I have been on a quest to retrofit my car with ZCP suspension for over a year now. It started when rldzhao first noticed that the JDM E92 M3 sat lower than ROW models; was compounded when BMW announced a revised suspension for the Edition model later that summer; and came to a head when the ZCP option was announced earlier this year. After a bit of research from Scott at BMW of Houston and Jason at Tischer BMW in Maryland, we quickly determined that all three variants had the same suspension components. At that point, it was simply a matter of importing the struts from BMW AG (not as easy as it sounds), matching up my car's options to the appropriate springs, and importing them -- also from BMW AG.

The suspension was installed at EAS yesterday, and even though I haven't had an alignment yet, I took the car for a quick sprint around the hills that overlook Irvine and Newport Coast last night. The difference is noteworthy. I was initially a bit surprised to find that the ride was somewhat softer than before. But after a few minutes, I realized that it wasn't softer per se, but more planted. In the past, the car had a slight tendency to become a bit unsettled on uneven pavement under acceleration while cornering in Sport mode. With the new setup, the car feels much more solid... much more confident.

I have more rubber on the road now than before too, as I installed a new set of wheels with 255f/275r PS2s, which is one size wider than our OEM 19" tires. Part of the confidence the car now exudes is undoubtedly due to the wider patch of contact that it has with the road, but the stability that the car exhibits because of the ZCP suspension is definitely noticeable as well. I plan on taking the car out on some more serious twisties next weekend once I have the alignment done, but I'm very happy with the change so far.

A few other notes:

1) No, this wasn't cheap. But for a component as critical as suspension, I would never opt for a non-OEM solution, even at a considerable discount over the premium that I most surely paid. I took this tack with my S2000, and it served me well then.

2) No, you can't really see the drop. I had a two finger gap in the rear and a three finger gap in the front before that are now down to one in the back and two in the front, but it's barely noticeable.

3) Pics are forthcoming. Tom's crew at EAS took some pictures during the installation process, and I'll post them up as soon as I have them.

On a separate note, this forum (i.e. its members) is really an invaluable source of information. I would never have been able to perform this upgrade without the wealth of knowledge on this site. Don't take it for granted!

Edit: Here are some pics:









More here:
http://www.m3post.com/forums/showthread.php?t=412085

[M3 Esq.]

Can you describe for us what was done? My understanding is that the ZCP option includes different shocks, springs, and wheels (as well as some remapping of EDC). Does your car have EDC? I am just wondering if this upgrade could be achieved for non EDC cars. Also, how much of the improvement you perceive could be attributable to the wider tires? Finally, can you give us an idea of the cost?

Thanks for the write up.

Cheers!

[FruitCake]

Nice!!! I knew if anyone was to do it, it was you./

[Trier Germany]

You should have opted for a nice premium set of coilovers. I can't even imagine how much money you spent for these OEM parts. I'm guessing highway robbery. It's the wider stance and tires you are feeling. First it would be impossible to feel this setup in normal driving. You would have to have a baseline at a local track.

[FruitCake]

Originally Posted by Trier Germany

You should have opted for a nice premium set of coilovers. I can't even imagine how much money you spent for these OEM parts. I'm guessing highway robbery. It's the wider stance and tires you are feeling. First it would be impossible to feel this setup in normal driving. You would have to have a baseline at a local track.

OEM is what he's looking for, and I don't blame him.

[Trier Germany]

Originally Posted by FruitCake

OEM is what he's looking for, and I don't blame him.

point noted

[aajami]

Originally Posted by Trier Germany

You should have opted for a nice premium set of coilovers. I can't even imagine how much money you spent for these OEM parts. I'm guessing highway robbery. It's the wider stance and tires you are feeling. First it would be impossible to feel this setup in normal driving. You would have to have a baseline at a local track.

Trier, the whole point is that I didn't want to opt for a set of aftermarket coilovers -- I wanted an OEM solution that would provide an incremental gain in handling, retain EDC functionality, provide a subtle drop, while not sacrificing everyday ride quality. To that end, a ZCP retrofit was my only option. That all said, I ended up paying just about the same as a set of KW v3s.

And you're right in suggesting that the modest gains in handling are attributable to both the new wheel/tire setup as well as the suspension, but the suspension improvements are definitely noticeable, subtle though they may be. I took her out again last night on Ortega Highway and was very pleased with her new disposition.

Originally Posted by McLoven

Can you describe for us what was done? My understanding is that the ZCP option includes different shocks, springs, and wheels (as well as some remapping of EDC). Does your car have EDC? I am just wondering if this upgrade could be achieved for non EDC cars. Also, how much of the improvement you perceive could be attributable to the wider tires? Finally, can you give us an idea of the cost?

McLoven, my car does have EDC, but I did not flash it with the changes to the Sport EDC that the ZCP option provides. I don't believe there's any way to retrofit the EDC settings. In that regard, my hardware retrofit changes are in line with the 2010 Edition suspension and the JDM M3. As mentioned in the OP, I swapped out all four stock shocks for ZCP shocks, and all four springs for ZCP springs. I also picked up the Style 359M wheels, but I wrapped them in slightly wider rubber, which also adds to the difference in handling. As I mention in the reply to Trier, I paid about the same as a set of KW v3s, though your mileage may vary. I send a bit of business toward the vendor that I purchased some of these parts from, so they cut me a discount.

PNs for anyone interested:

Front Left ZCP strut 31312283917
Front right ZCP strut 31312283918
Rear ZCP struts 33522283920 (x2)

Spring PNs have to be obtained through BMW, since they're matched directly to your VIN.

I edited the OP with some pics.

[OC ///M]

Nice work aajami. I can appreciate you wanting to retain the OEM components.

I am confident that the zcp suspension in my '11 is much improved over the standard in my previous '08 and am sure you're enjoying it as well.

I'm curious, does the increase in the outside diameter of your tires affect your speedometer reading or speed off the line? ...or just a negligible difference?

[rzm3]

Do you have pictures with ZCP and non-ZCP shocks side by side?

[aajami]

Originally Posted by rldzhao

Do you have pictures with ZCP and non-ZCP shocks side by side?

Not side-by-side, unfortunately (unless Tom @ EAS snapped some). The main difference that I noticed was the spring perches on the front struts were a bit lower on the assembly than the standard struts.

[aajami]

Originally Posted by OC ///M

I'm curious, does the increase in the outside diameter of your tires affect your speedometer reading or speed off the line? ...or just a negligible difference?

The difference in size is so small that the speedometer error is less than 1%. So at 80MPH, it'll read 79.3 -- pretty negligible.

[STALKER]

Good to know that it can be done, thanks for sharing.
Car looks sharp!!
I might have gone another route myself, but I can totally understand wanting to stay OEM for your own comfort level.

[signes]

Originally Posted by STALKER

Good to know that it can be done, thanks for sharing.
Car looks sharp!!
I might have gone another route myself, but I can totally understand wanting to stay OEM for your own comfort level.

+1

[alpina527]

Well done on finally getting it all sorted. This is a route that I might take.

[aajami]

Originally Posted by alpina527

Well done on finally getting it all sorted. This is a route that I might take.

Thanks. Your help was invaluable.

[1cleanm3]

coming from a zcp owner....

yes the handeling is better then a reg m3(buddy has a reg one), HOWEVER i have no idea how much you spent. Im guessing this setup cost you like atleast 3k. I would rather get kw v3's. Id put my money itll handle/perform much better. I know i read you wanted oem however not worth it.

[aajami]

Originally Posted by Boosted335

coming from a zcp owner....

yes the handeling is better then a reg m3(buddy has a reg one), HOWEVER i have no idea how much you spent. Im guessing this setup cost you like atleast 3k. I would rather get kw v3's. Id put my money itll handle/perform much better. I know i read you wanted oem however not worth it.

It didn't even run me $2K, let alone $3K.

[Technic]

Originally Posted by aajami

Not side-by-side, unfortunately (unless Tom @ EAS snapped some). The main difference that I noticed was the spring perches on the front struts were a bit lower on the assembly than the standard struts.

So are the springs shorter than the non-ZCP or the 10mm drop is from the perches?

[ersin]

Originally Posted by aajami

The difference in size is so small that the speedometer error is less than 1%. So at 80MPH, it'll read 79.3 -- pretty negligible.

The speedo already reads high, especially the faster you go. So, with the slower than stock reading you're actually getting closer to the true speed.

BTW, nice work. I'd go aftermarket myself, but I'm glad you got to do it OEM the way you wanted.


Cheers.

[Slpnbyu]

Originally Posted by aajami

PNs for anyone interested:

Front Left ZCP strut 31312283917
Front right ZCP strut 31312283918
Rear ZCP struts 33522283920 (x2)

Spring PNs have to be obtained through BMW, since they're matched directly to your VIN.

Do you know if these are the same part numbers as what would be used on the E90, or are they E92 specific?

I wonder why they are matching the spring part numbers with your VIN. I have read in the past (E46 CSL) that they used to match VIN with part numbers so you couldn't order the parts unless you really had a CSL.

[Technic]

Originally Posted by Slpnbyu

Do you know if these are the same part numbers as what would be used on the E90, or are they E92 specific?

I wonder why they are matching the spring part numbers with your VIN. I have read in the past (E46 CSL) that they used to match VIN with part numbers so you couldn't order the parts unless you really had a CSL.

I would guess that it has to do with the Vehicle Order that that VIN has to show (ZCP). The springs are matched to the shocks which are matched to the new EDC algorithm, which makes up the ZCP option code in the VO, which is in the VIN.

In simpler words, BMW wants to make sure that if/when you crash you are not going to use your ZCP retrofit as the possible cause for a lawsuit.

[WCH]

Originally Posted by OC ///M

I am confident that the zcp suspension in my '11 is much improved over the standard in my previous '08 and am sure you're enjoying it as well.

+1. It's hard to know objectively but this is my feeling as well.