Suspension Replacement!

[heligarret]

Wondering what everyone suggests for strut and shock replacement for 2007 Z4M Roadster? OEM or aftermarket? What brand?

I do have 19" wheels.

Not wanting to spent thousands on coil overs!

[Twixboy]

How many miles are on the car? No need to spend thousands on coilovers. A set of Megans can be had for under $1k. You mention you don't want to buy coilovers, but you also said you're just looking for shock/strut replacements. Are you keeping your stock springs? If you also want to replace your springs, do you want to keep it at stock height or is a slight drop ok?

[KevinC]

At 41k miles I replaced my shocks with Bilstein HDs. Kept stock springs, run stock 18" rims with Michelin PSS. Firmer than stock (which were well-worn by the time they were replaced), all in all, the "right" replacements for me. And should last 100k miles or more, warranted for life to original purchaser.

[StickMon]

I did the same at about 80k. (Yea, they were shot).
Replaced everything except the springs.
Used RE rear upper mounts.

[jdoublehcubed]

Originally Posted by StickMon

I did the same at about 80k. (Yea, they were shot).
Replaced everything except the springs.
Used RE rear upper mounts.

I've been wondering if there is any reason to replace the springs when I do the same.

My car is at 88k. My front springs are at 88k, but my rears are only at about 25k due to replacement from the typical broken spring problem.

[NickyC]

H&R coilovers are fantastic for like $1250.

[StickMon]

Hmmm.
I had imagined that the springs would be largely indestructible.
I hadn't heard of "typical broken spring problem" until now.
Search results show plenty of destructability.
Looks like it's environment dependent. Something else to keep an eye on.

j2h^3, you're where I am. Surprised you had that happen around here. Seems to be due to rain + salt.

[KevinC]

I've never heard of the springs breaking in a dry environment - seems to be confined to snowy/salted road areas. But it sounds like one failed in Pasadena - about as good of an environment as possible. Hmm.

[Westersund]

Originally Posted by NickyC

H&R coilovers are fantastic for like $1250.

Can't agree more, you're talking about the Street Performance H&R's eh?

If you don't need coilovers I'd go for Yellow Koni's or Bilstein HD.

[Daemonblitz]

I took out my stock shocks at 82k miles and they were still working fine, on top of that I had H&R springs on for the last 20k miles too. I ended up going to H&R Coilovers and am very happy with them so far.
If you really want low budget and were completely happy with stock setup, there are lots of guys who took their OEM suspension off early and they probably still have it lying around for cheap. Just an idea.

[NickyC]

Originally Posted by Westersund

Can't agree more, you're talking about the Street Performance H&R's eh?

If you don't need coilovers I'd go for Yellow Koni's or Bilstein HD.

Yep! I had H&R SPs on my last Z4M and hope to order another set for my newer Z4M soon. I loved 'em! Be sure to get the RE RSMs too OP!

[Westersund]

Originally Posted by NickyC

Yep! I had H&R SPs on my last Z4M and hope to order another set for my newer Z4M soon. I loved 'em! Be sure to get the RE RSMs too OP!

I didn't change my RSM, maybe I should have. But I think the car is firm/stiff enough as is. If it was a track car I would have changed them out.

[GP20]

Maybe I've been spoiled by my previous TCKline & Ground Control coilovers. When I test-drove a Z4MR with H&R coilovers, I thought the suspensions were garbage. Stiff for the sake of being stiff but also the handling was nowhere near as good as the TCK's & GC's. It was a dreadful 5-minute drive. I'd even say that the H&R springs with Bilstein dampers handle better and are more comfortable and simply make the Z4M more fun to drive than the H&R coilovers.

[heligarret]

Car has 80,000 miles. Running 19" wheels. Don't want the ride any stiffer and really like how the car rides. Pretty sure the fronts are done. Still undecided

[StickMon]

I still recommend the Bilstein HDs. I think they're pretty much stock stiffness but may be more durable.
I didn't notice any extra harshness. Still rides like the same stagecoach.

[Vanne]

i went for Bilsteins HD and HR springs, beaut setup, (on recommendations of Shippy) and he was spot on. my oem stuff was shot though, it had 120Kmiles on it, so no wonder.

[jdoublehcubed]

Originally Posted by StickMon

Hmmm.
I had imagined that the springs would be largely indestructible.
I hadn't heard of "typical broken spring problem" until now.
Search results show plenty of destructability.
Looks like it's environment dependent. Something else to keep an eye on.

j2h^3, you're where I am. Surprised you had that happen around here. Seems to be due to rain + salt.

I am now, but I moved here from Philadelphia 6 months ago. One of the rear springs broke just after I bought the car, also in the mid atlantic.

Over on one of the other Z4 forums (can't remember which one), they have a thread tracking the broken rear spring problem. Last time I saw it they had something like 100 people who had posted with the same proboem.

I was mostly wondering if they lose any of their stiffness over time, etc. I think the breaking issue was probably a manufacturing defect, as I can't recall seeing anyone having the issue a second time after replacing the original set.

[Finnegan]

Originally Posted by heligarret

Wondering what everyone suggests for strut and shock replacement for 2007 Z4M Roadster? OEM or aftermarket? What brand?

I do have 19" wheels.

Not wanting to spent thousands on coil overs!

No trying to thread jack by I have a 16k mile or so stock suspension off a coupe if you're interested. Pm me.

[Twixboy]

Originally Posted by Finnegan

No trying to thread jack by I have a 16k mile or so stock suspension off a coupe if you're interested. Pm me.

Just curious, how does the Z4 M suspension compare to the 2004 3.0i M sport suspension? I'm assuming its a direct swap, but would it be an upgrade?

[trevor]

Originally Posted by StickMon

I did the same at about 80k. (Yea, they were shot).
Replaced everything except the springs.
Used RE rear upper mounts.

My car made it over 200k without an issue. I would say the primary contributor to this issue is your PARKING. Parking on inclines take a HUGE toll on the suspension. The handbrake is there to protect your car just in case, not to park it. Soon the handbrake will also stop working if you park on slopes too much.

[chickdr]

Originally Posted by Twixboy

Just curious, how does the Z4 M suspension compare to the 2004 3.0i M sport suspension? I'm assuming its a direct swap, but would it be an upgrade?

How does the suspension of the E85 M Roadster differ from that of the regular Z4 roadster?
The E85 M Roadster utilizes the same basic MacPherson strut/multi-link suspension design as the standard E85/E86 Z4 range. However, it has been substantially modified by BMW M GmbH with the following changes:
-wider front track (by half an inch)
-revised lower aluminum front control arms with a design similar to that of the E46 M3
-steering knuckles bolted directly to the front struts
-larger and stronger rear subframe designed to accommodate the M Differential Lock
-modified longitudinal links in the rear suspension
-modified wheel bearings
-specific spring and shock rates
-thicker front (27 mm) and rear (21.5 mm) anti-roll bars

[Finnegan]

^This