Sponsored by The Tire Rack

[W Cole]

I have searched thoroughly and am very surprised that I couldn't find anyone who has lowered their non-ZCP car by installing ZCP springs. I saw one member who retrofitted the entire ZCP strut and spring assembly onto this non-ZCP car and I noted in one post he questioned if the ZCP struts are any different than non-ZCP.

There seems to be a ton of conflicting information about the differences between ZCP and non-ZCP cars. I was wondering if anyone could lend some insight on the following:

- Are the ZCP struts different than non-ZCP?

- How is the lowering accomplished on a ZCP car? Springs? Different spring pads? Altered spring perch location? Or a combination of?

I could be going in the wrong direction entirely and perhaps this is why no one else has attempted this. I am looking for a very mild drop that will not prematurely wear out my struts and other suspension components. Perhaps the Dinan stage 1 kit is my best bet as I have read it provides a very similar ride height to ZCP?

Thanks.

[tlp]

There is a lot of conflicting info on that topic. The struts are different between EDC &ZCP as they have different part numbers. The exact confirmed differences are unknown. Some say lower perch or valving or a combination of the two. Since your sensitive to ride height and OEM component wear & tear you should consider the KW Sleeve over kit and call it day.

[tibra1]

Can you even purchase ZCP springs w/o the dampers?

The ZCP suspension sits 0.4 inches lower

[tlp]

Originally Posted by tibra1

Can you even purchase ZCP springs w/o the dampers?

The ZCP suspension sits 0.4 inches lower

You can but there are no discrete part #'s for springs. The springs are an aggregate of the chassis and options associated to your build stored with your VIN#. Somewhere BMW has a matrix of the spring that was used on the car during production based on the initial production.

[aajami]

Originally Posted by W Cole

I have searched thoroughly and am very surprised that I couldn't find anyone who has lowered their non-ZCP car by installing ZCP springs. I saw one member who retrofitted the entire ZCP strut and spring assembly onto this non-ZCP car and I noted in one post he questioned if the ZCP struts are any different than non-ZCP.

There seems to be a ton of conflicting information about the differences between ZCP and non-ZCP cars. I was wondering if anyone could lend some insight on the following:

- Are the ZCP struts different than non-ZCP?

- How is the lowering accomplished on a ZCP car? Springs? Different spring pads? Altered spring perch location? Or a combination of?

I could be going in the wrong direction entirely and perhaps this is why no one else has attempted this. I am looking for a very mild drop that will not prematurely wear out my struts and other suspension components. Perhaps the Dinan stage 1 kit is my best bet as I have read it provides a very similar ride height to ZCP?

Thanks.

I'm the guy who did the ZCP conversion.

I don't think there's clear consensus on what the difference between the struts are, primarily because there are no obvious visual differences between the two. My belief is that their valving and compression rates are a bit different based solely on the fact that they have different part numbers and different prices. It was also interesting to note that the ZCP struts are the same ones found on the 1M and the standard Japanese market M3.

As for the lowering, there's also no consensus there. The only difference in part numbers between ZCP and non-ZCP cars are the struts and springs -- the spring pads are the same part. It's either done through the springs or the spring perches (though as some have noted, the difference in perch location is practically imperceptible between the two struts).

Why not just order ZCP springs and see if you get the drop. As I recall, they're cheaper than the Dinan Stage I kit. If you don't get the drop, then you can either return the springs or buy the struts. Either way, you'd confirm where the drop comes from.

[jonasaurus]

Aajami's ZCP retrofit post
http://www.m3post.com/forums/showthr...ami+zcp&page=1

I'm still curious to this question of how is the 10mm drop achieved. Given they never offered ZCP for E90 M3s here in the UK, in wanting to keep it OEM, this appears to be a good solution for achieving slightly improved handling dynamics as well as aesthetics.

[THE TECH]

Sounds like a lotta work for little gain. Just get a good set of aftermarket springs. 10mm is hardly noticeable.

[ChrisK]

I put ZCP wheels on my non-ZCP '11 and no-one including other ZCP owners can tell the difference. Everyone has always asked me if I lowered my car. Who knows what BMW did in '11

[W Cole]

Originally Posted by aajami

I'm the guy who did the ZCP conversion.

I don't think there's clear consensus on what the difference between the struts are, primarily because there are no obvious visual differences between the two. My belief is that their valving and compression rates are a bit different based solely on the fact that they have different part numbers and different prices. It was also interesting to note that the ZCP struts are the same ones found on the 1M and the standard Japanese market M3.

As for the lowering, there's also no consensus there. The only difference in part numbers between ZCP and non-ZCP cars are the struts and springs -- the spring pads are the same part. It's either done through the springs or the spring perches (though as some have noted, the difference in perch location is practically imperceptible between the two struts).

Why not just order ZCP springs and see if you get the drop. As I recall, they're cheaper than the Dinan Stage I kit. If you don't get the drop, then you can either return the springs or buy the struts. Either way, you'd confirm where the drop comes from.

So there is a slight difference in perch locations?

[aajami]

Originally Posted by W Cole

So there is a slight difference in perch locations?

I don't know. I wasn't able to measure the struts side by side.

As for the poster above, it does appear that the car might sit a hair higher than a ZCP.

At any rate, I wanted peace of mind that comes with an OEM solution, and I was able to get the necessary hardware for relatively cheap.

[W Cole]

Originally Posted by aajami

I don't know. I wasn't able to measure the struts side by side.

As for the poster above, it does appear that the car might sit a hair higher than a ZCP.

At any rate, I wanted peace of mind that comes with an OEM solution, and I was able to get the necessary hardware for relatively cheap.

It appears the poster above only retrofitted wheels and not any suspension components.

Thats unfortunate no one has gotten the two struts side by side. I wonder if my dealerships parts department would have the two in stock and let me compare?

Do you know if the ZCP cars use the same bump stops? Do they just sacrifice 10mm of suspension travel?

[aajami]

Originally Posted by W Cole

It appears the poster above only retrofitted wheels and not any suspension components.

Thats unfortunate no one has gotten the two struts side by side. I wonder if my dealerships parts department would have the two in stock and let me compare?

Right. But he was implying there was no visual difference between the two cars.

I have a set of front and rear non-ZCP struts lying around. I've offered to ship them out to anyone who has a set of ZCP struts on hand that would also be willing to do a little side-by-side comparison in the name of science before, but there have been no takers.

[Dave07997S]

I notice the difference between ZCP and non...Heres my car with a 285/30/19 which is even shorter than the OEM 265/35/19





It is slight, but I do notice it.

Dave

[aajami]

Originally Posted by Dave07997S

I notice the difference between ZCP and non...Heres my car with a 285/30/19 which is even shorter than the OEM 265/35/19





It is slight, but I do notice it.

Dave

Any excuse to post pics of your beautiful car against the PDR backdrop, eh Dave?

[Dave07997S]

Originally Posted by aajami

Any excuse to post pics of your beautiful car against the PDR backdrop, eh Dave?

How'd you know..

How are you doing..survive the 4th of July. PDR was crazy at the jungle. One party was over 500 people.

Dave

[aajami]

Originally Posted by Dave07997S

How'd you know..

How are you doing..survive the 4th of July. PDR was crazy at the jungle. One party was over 500 people.

Dave

I spent it in HB. First year that they've allowed fireworks in a long time. The city shut down two blocks of PCH north of the pier, and the whole street was like a mini Burning Man Festival -- good times.

I just got the CRT lip installed on my car. You should check it out soon.