E89 suspension change coming up

[JohnG7]

Hey guys and gals,
I've been looking for info so that I get this right. My Z4 (2010-s30i) is about to get new suspension parts (shocks,struts,springs) and while apart, I want to replace parts that will eventually need replaced (mounts).

Most likely I will install a Bilstein b12 pro kit, which will drop it some (1/2"-3/4+). Will get a 4 wheel alignment when completed. My plan is to have the new front assembly ready just to stab in place after pulling the old. This requires me to purchase all the needed parts, then compress the front springs. Also will require new front strut mounts. I will swap out the rear shock mounts (RSM) while the back is apart. Since our E89 shares many parts with other BMWs, I started trying to cross reference RealOEM part numbers, the prices vary widely, does the quality also?

eBay has these mounting parts (with warranty) often times cheap, (red flag?). I want to buy only quality parts, oem quality or better when needed. Anyone have any advice on which parts I should buy? the smart money parts? I do not want to overspend, nor buy anything of low quality (with your help). How good is good enough on shock mounts?

Has anyone here used this Bilstein pro kit (with springs)? Or do you have a better solution to offer? Mine does not have the sports suspension, I am willing to sacrifice some ride quality, but keeping this as a comfortable daily driver is my primary goal. The handling improvements will be nice but secondary to ride quality. Does anyone reinforce the strut towers (part# 51717036781), looks to be cheap and easy, but is this needed?

A set of different sway bars may be in the future, along with bushings, but for now she's still tight (low mileage @30k).

Lastly, anyone know of a DIY showing the needed trunk liner removal tips, or know what this requires? I understand the mechanicals, just not what I am looking at inside.

For the last few weeks, I've searched and researched, finding very little that helps with these questions. Our cars share parts with many others, is great unless you are dyslexic like me.

Anyone have any tips or pointers? A full C/O kit would be overkill for my needs, my goal is to (try) to keep this in the $1k range. Which shock mounts should we stay away from? What results have you had with this setup, or was this task much for an amateur with wrenches?

Thanks all...

[Finnegan]

Originally Posted by JohnG7

Hey guys and gals,
I've been looking for info so that I get this right. My Z4 (2010-s30i) is about to get new suspension parts (shocks,struts,springs) and while apart, I want to replace parts that will eventually need replaced (mounts).

Most likely I will install a Bilstein b12 pro kit, which will drop it some (1/2"-3/4+). Will get a 4 wheel alignment when completed. My plan is to have the new front assembly ready just to stab in place after pulling the old. This requires me to purchase all the needed parts, then compress the front springs. Also will require new front strut mounts. I will swap out the rear shock mounts (RSM) while the back is apart. Since our E89 shares many parts with other BMWs, I started trying to cross reference RealOEM part numbers, the prices vary widely, does the quality also?

eBay has these mounting parts (with warranty) often times cheap, (red flag?). I want to buy only quality parts, oem quality or better when needed. Anyone have any advice on which parts I should buy? the smart money parts? I do not want to overspend, nor buy anything of low quality (with your help). How good is good enough on shock mounts?

Has anyone here used this Bilstein pro kit (with springs)? Or do you have a better solution to offer? Mine does not have the sports suspension, I am willing to sacrifice some ride quality, but keeping this as a comfortable daily driver is my primary goal. The handling improvements will be nice but secondary to ride quality. Does anyone reinforce the strut towers (part# 51717036781), looks to be cheap and easy, but is this needed?

A set of different sway bars may be in the future, along with bushings, but for now she's still tight (low mileage @30k).

Lastly, anyone know of a DIY showing the needed trunk liner removal tips, or know what this requires? I understand the mechanicals, just not what I am looking at inside.

For the last few weeks, I've searched and researched, finding very little that helps with these questions. Our cars share parts with many others, is great unless you are dyslexic like me.

Anyone have any tips or pointers? A full C/O kit would be overkill for my needs, my goal is to (try) to keep this in the $1k range. Which shock mounts should we stay away from? What results have you had with this setup, or was this task much for an amateur with wrenches?

Thanks all...

Think you'll want to ask the mods to move this to the E89 section. Not many of us in the E85 world are going to be able to offer much of an opinion on this.

[JohnG7]

Oops,

I jump around the forums and thought I was in the general area.

Might as well just leave this here and maybe resubmit another thread in a few weeks in the correct forum.

MODS, should we just delete this and I'll restart it, OR,
can ya move it. My bad! NAH, MODS, just leave it here or delete...

There's a reason I just just read


BUT-- There has gotta be more experience over here with owners who have modified or repaired struts and springs. I don't mind spending for something but hate wasting money. I know many here have modified their e85/e86 but I'm not sure the differences.

Thanks Finnegan.

[Finnegan]

Originally Posted by JohnG7

Oops,

I jump around the forums and thought I was in the general area.

MODS, should we just delete this and I'll restart it, OR,
can ya move it. My bad!

There's a reason I just lurk


BUT-- There has gotta be more experience over here with owners who have modified or repaired struts and springs. I don't mind spending for something but hate wasting money. I know many here have modified their e85/e86 but I'm not sure the differences.

Thanks Finnegan.

YW.

FWIW I'd look at H&R coilovers, or Bilstein kits which are already on your list. (Including the pricey DampTronic system.) You don't need a track based set up from what you're looking for, but don't cheap out, you'll regret it later, and end up paying twice as much in the end. Save up if you can't afford it all now--quite a few of us have made that mistake. I'd avoid fleabay like the plague.

[JohnG7]

Originally Posted by Finnegan

YW.

FWIW I'd look at H&R coilovers, or Bilstein shocks/struts (including the pricey DampTronic system). You don't need a track base set up from what you're looking for, but don't cheap out, you'll regret it later, and end up paying twice as much in the end. Save up if you can't afford it all now. I'd avoid fleabay like the plague.

It's nothing like I cannot afford it, it's that I'm kinda tight. I subscribe to keeping to my side of diminishing returns. I really do not think I can justify a full coilover system. I have looked into many of my options, I believe the Bilstein B12 pro kit looks to be splitting the difference between cheaping out and going all out. I have "cheaped out and regretted it before" but more often I have gone way beyond what was needed and knowing I overspent. Being retired, I merely set my goals down a notch or 2.

Trying to find feedback from any particular setup is not easy (for a e89) yet I have heard little negative feedback on the B12 pro kit once installed. I PM'd a few who had these installed and none have regrets. I am looking for the best in budget solution that hopefully is a one time solution- one that does not detract from ride comfort too drastically, and not break the bank. Most threads I find are where we just change shocks, or struts since ours have both. That is my def of cheaping out (set of b4 bilsteins), I cannot argue that as not viable.
Nest up my list is the shock/strut/spring kit (like this b12). If I go this route, I do wish to replace everything recommended. My dealer priced the FSM at $130/ea, RSM at $88/ea. Others list the same part# much cheaper. Then, can get the B12 delivered for $685. I can live with this, but then I see Monroe offers FSM/RSM at much better prices (none listed for e89), as well as the fleabay crap (warranted of course).

I am familiar with the phrase, "buy once, cry once" when talking quality, I'm just reaching for the lower bar this time.

My main goal started as just preventing my banging the front strut stops, like I do. The car drives and handles great, our roads do give my suspension the 100% workout.

Reusing my low mileage shock mounts is done all the time, would you? I prefer new if any question, but which ones?

Sorry if I come off argumentative, not my intention. I really do not "cheap out" at all if I can justify dropping the coin, nor creating a car like my last Carrera that was no joy to drive unless at speed.

My days of racing are gone, now I just drive fast. The old me liked banging gears, now I enjoy the journey differently, not just the destination. It helps to have a little coin left once there.

Does most here reuse the shock/strut mounts, or am I overthinking this again (most likely)?

If anyone has ANY knowledge of these Bilstein B12 kit installation that was problematic I really want to know (PM or post). Also if you have installed a coilover system and can explain why you feel the results were worth the outlay. Remember, this is a grocery getter that most likely will never see track use.

Finnegan, I will indeed look into those again, my number is just a number I tossed out as a goal. I rarely underspend on anything, am trying to limit my usual going over and beyond.
The general opinion I have is often coilovers require more effort to maintain down the road. Is this wrong? Most that applies to the e89 applies to the e85/e86 pretty closely, except some parts. Turner offers the individual parts I need as well as dealer.

This is a project for later, our heat is too bad for a while. I will start acquiring parts when I figure which parts to gather. The large price difference in mounts is curious, but when they say "just as good as" maybe not best used as a critical part.

[Finnegan]

Originally Posted by JohnG7

It's nothing like I cannot afford it, it's that I'm kinda tight. I subscribe to keeping to my side of diminishing returns. I really do not think I can justify a full coilover system. I have looked into many of my options, I believe the Bilstein B12 pro kit looks to be splitting the difference between cheaping out and going all out. I have "cheaped out and regretted it before" but more often I have gone way beyond what was needed and knowing I overspent. Being retired, I merely set my goals down a notch or 2.

Trying to find feedback from any particular setup is not easy (for a e89) yet I have heard little negative feedback on the B12 pro kit once installed. I PM'd a few who had these installed and none have regrets. I am looking for the best in budget solution that hopefully is a one time solution- one that does not detract from ride comfort too drastically, and not break the bank. Most threads I find are where we just change shocks, or struts since ours have both. That is my def of cheaping out (set of b4 bilsteins), I cannot argue that as not viable.
Nest up my list is the shock/strut/spring kit (like this b12). If I go this route, I do wish to replace everything recommended. My dealer priced the FSM at $130/ea, RSM at $88/ea. Others list the same part# much cheaper. Then, can get the B12 delivered for $685. I can live with this, but then I see Monroe offers FSM/RSM at much better prices (none listed for e89), as well as the fleabay crap (warranted of course).

I am familiar with the phrase, "buy once, cry once" when talking quality, I'm just reaching for the lower bar this time.

My main goal started as just preventing my banging the front strut stops, like I do. The car drives and handles great, our roads do give my suspension the 100% workout.

Reusing my low mileage shock mounts is done all the time, would you? I prefer new if any question, but which ones?

Sorry if I come off argumentative, not my intention. I really do not "cheap out" at all if I can justify dropping the coin, nor creating a car like my last Carrera that was no joy to drive unless at speed.

My days of racing are gone, now I just drive fast. The old me liked banging gears, now I enjoy the journey differently, not just the destination. It helps to have a little coin left once there.

Does most here reuse the shock/strut mounts, or am I overthinking this again (most likely)?

If anyone has ANY knowledge of these Bilstein B12 kit installation that was problematic I really want to know (PM or post). Also if you have installed a coilover system and can explain why you feel the results were worth the outlay. Remember, this is a grocery getter that most likely will never see track use.

Finnegan, I will indeed look into those again, my number is just a number I tossed out as a goal. I rarely underspend on anything, am trying to limit my usual going over and beyond.
The general opinion I have is often coilovers require more effort to maintain down the road. Is this wrong? Most that applies to the e89 applies to the e85/e86 pretty closely, except some parts. Turner offers the individual parts I need as well as dealer.

This is a project for later, our heat is too bad for a while. I will start acquiring parts when I figure which parts to gather. The large price difference in mounts is curious, but when they say "just as good as" maybe not best used as a critical part.

OK, I have a better picture of what you're looking to do, and what your requirements are. I wasn't suggesting you couldn't buy a more expensive system, I tend to want to get the best bang for my buck as well. What I was trying to say, and maybe didn't explain well enough, was to make sure the requirements for your application are complete, and the solution fully meet those. If you can do that for $500 great. If $1000 only gets you halfway, or worse yet doesn't address key issues, that's not $1000 well spent if you could've spent 1500 to nail down everything. I'm a big fan of the cheapest solution to get all the requirements met. I suspect we're on the same page regarding those things. (Totally get the "no fun unless warp speed" type driving experience cars on public roads. Been there done that too.)

I'd recommend figuring out what's causing the suspension to bottom out. It could be a function of insufficient suspension travel, worn shocks, or spring rates that are too low, coil bind, etc. I took a quick look at that Bilstein kit, and those springs have a lower spring rate than stock. If the stock spring rate is your issue, then going to a lower spring rate is just going to increase the problem you already have.

Coilovers to require maintenance and re-valving from time to time, but when you're looking at this type of kit, you have a greater choice of spring rates and compression (adjustable shocks) and in higher end kits rebound. Now I think a lot of that's going to be overkill for what you're trying to do. On the other hand if you're driving style and the roads require a greater ability to tune the suspension, I'm not sure that the kit that you're thinking of is going to get you where you need to be given the shock isn't adjustable and given the spring rates are softer than stock.

There may be a middle road. You may want an adjustable (Koni or similar) shock, and a spring that matched to the shock's characteristics. That's not going to be a coil over, it's more of a standard system, but a bit more customized to your needs and adjustable which gives you some future flexibility. You might want to give Turner motorsports a call and discuss your needs (and current issues like bottoming out) with them. They carry the Bilstein kit, Koni, various springs, bump stops, etc.

Regarding the FSM and RSM, yes I'd replace them if they're stock at that mileage. I'm not sure what the set up is on the E89, but on the E85/86 the stock RSM requires digging into the trunk every time you want to swap out or change a shock. Rogue RSMs have the nuts on the wheel not the trunk side. That means you just need to remove a wheel, or if your shop is doing it they just need to remove it, just a wheel. That cuts down a lot on the labor no matter who's doing the work for the future. FSM's tend to wear and tear over time, IMO should be replaced when you replace the shock of the springs if you're doing that as a preventative maintenance or wear item replacement.i

[JohnG7]

Good advice, I'll give Turner a call- I had priced some of this from them and they are who said they prefer the FSM from another model over the dealer oem in their ad.

Last week I called Bilstein US and talked with a couple of their R&D engineers with exactly this issue, both of their answers were the added damping of the included B8 strut damps the reaction (I guess their way). Actually I like the current suspension most of the time, it rarely bottoms out (mostly one new exit I use). The lead engineer basically "promised" I'll love the B12 kit on my Zed. Maybe they are salesmen also??

We think very similar. Nothing bothers me more than almost doing something right. The issue I have is I no longer can as easily afford going overboard. Everything is a tradeoff for something.

Am finding these shock mounts all over the price range, I don't plan to cheap out here either. I know many add the strut support while everything is open (about $11 each), but is there any benefit at all? I do not want to create any unintended problems, NOR when complete say I should have replaced x or y. All the trunk liner does indeed have to be loosened and folded out of the way. Someone who knows what they are doing would make it quick work, me, it'll take a while. Time I have, for now.

Thanks much for the info. I do plan to swap all the shock/strut mounts and rubber while apart. I may consider a few bushings after this project, but everything appears solid (just soft).

Do you buy the engineers answer that the increased damping and lower spring rate retard the action therefor saving my poor bumpstops. I kinda bought it, it won't be the first grand I blew. Nor maybe the last.

UPDATE: I called Turner today and asked a ton of questions, he answered very similar to Finnegan about the spring rates. I then mentioned the Bilstein conversation and his answer of the stiffer damping. He agreed, then told me the oem mounts are fine for my needs. They all usually say is rare for a customer to complain
Hell, even if it still does bottom out after the work, I can live with it, and enjoy some benefit. My opinion is these shocks are just soft. I prefer some softness, these new springs are said to act progressive, but not really progressive?? I don't really care as long as the benefit is real and it lasts a while. Plus, the drop looks good when done right.

Looking at FSM and RSM (mounts) I find oem (Sachs), Lemforder, Mevotech, Monroe, Moog, maybe others. Prices run the scale, any of those to stay away from. I have heard of several broke mounts through the years, but I think most were old or in reuse. I found several fairly cheap, probably some china garbage working into everything.

And, is there any point in changing out sway bushings at this point?

Re-edit to add- These are the RSM I will order. (@$60pr)
Rear Shock Mounts (RSM) - Heavy-Duty - E30, E36, E46, Z3, Z4 (Pair)
Mfg Part #
33521132104-K

Turner Part #
T#302960