Help with Suspension Refresh at 50k miles/10 years

[BMWCurves]

Peter,

Do you have a direct link to buy the spherical RTABs? I'd like to put them and a link in the first post as an alternative.

[rkneeshaw]

Did some googling on those bimmerworld spherical RTABs, turns out it is NOT the same bearing as is used in the rear control arm location, but it IS a BMW OEM bearing. But they refuse to say from what BMW application or location in order to protect their trade secrets.

http://www.m3forum.net/m3forum/showt...511357&page=10

Also, there is another 11 page thread on m3forum.net regarding these bimmerworld spherical bearings and everyone reports NO increase in NVH, and that the car just feels amazing afterwards.

There were a few reports of clicking from early adopters due to the sleeve fitting a little loose in the rear control arm, but bimmerworld has updated the product since then to account for those tolerances and has shims available for those early adopters that still have issues.

If I didn't JUST get an alignment done I would be so tempted to get these in like right now.

[Vas]

Interesting read in that thread.

Anybody that bought one of these want to post up close pics of the parts?

[slater]

$40 for z4m rubber

true, but not with limiters (i forgot to specify. ). should be $80 with limiters, which is what we're using for comparison here.

Peter,

Do you have a direct link to buy the spherical RTABs? I'd like to put them and a link in the first post as an alternative.

yep, this is actually where i bought mine - cheaper than directly from BW, and free shipping to boot!

http://www.custom-performance.net/pr...idcategory=261

Did some googling on those bimmerworld spherical RTABs, turns out it is NOT the same bearing as is used in the rear control arm location, but it IS a BMW OEM bearing. But they refuse to say from what BMW application or location in order to protect their trade secrets.

http://www.m3forum.net/m3forum/showt...511357&page=10

Also, there is another 11 page thread on m3forum.net regarding these bimmerworld spherical bearings and everyone reports NO increase in NVH, and that the car just feels amazing afterwards.

There were a few reports of clicking from early adopters due to the sleeve fitting a little loose in the rear control arm, but bimmerworld has updated the product since then to account for those tolerances and has shims available for those early adopters that still have issues.

If I didn't JUST get an alignment done I would be so tempted to get these in like right now.

haha - i had read the same threads. now you see why i had to have them. pics below of the guts so you can see them.

Interesting read in that thread.

Anybody that bought one of these want to post up close pics of the parts?

yep, just took some pics.

pic 1: here you can see the opened BW spherical bearing and case, alongside a new lemfoerder 'balljoint' rear hub bushing. it's not really a bushing, it's a sealed spherical bearing. you can also see that the lemfoerder box has the dimensions on the box, so we could potentially find the OE part that BW users by simply measuring. note that the BW unit is pressed into the housing - i could not push it out by hand. also, you can see that the boots are different.

pic 2: side by side. clearly the sealed spherical bearing that BW uses is shorter and therefor most likely capable of rotating more.

hope that helps.

peter

[BMWCurves]

Thanks for the update, Peter!

[AggieBlake]

Great thread, guys! This has been very helpful to read through as I prepare to do FCAB's and RSM's soon. I got under the car last night to see what else needs to be replaced, and finally found the date code on the shocks. They're original. So at 99k miles and 11 years, I think they're due for replacement Based on what I'm reading here and in similar threads, it looks like the Koni sports on my current springs are the way to go (the springs show no signs of corrosion - it's a TX and FL car - no salt).

So William, Peter, Vas, anyone... would any of you suggest I look at anything other than the Koni's on current springs for my application? Here's my requirements:

- Mostly DD duty and lots of that with kids. So it needs to be comfortable on road.
- Occasional track and autoX (perhaps 5 total events a year), but not competing - just recreational. I'm not looking for absolute performance on track, just competence. Damping adjustability is a nice bonus since it allows some easy tuning at the track. But it's not essential.
- No desire for significant lowering/stancing. I'm happy at stock ride height, but could probably drop a half inch all around without beginning to scrape or bottom out on our subpar roads.

Any of you know if Koni's will be back on 25% off sale sometime in the next 4 months?

[Vas]

Great thread, guys! This has been very helpful to read through as I prepare to do FCAB's and RSM's soon. I got under the car last night to see what else needs to be replaced, and finally found the date code on the shocks. They're original. So at 99k miles and 11 years, I think they're due for replacement Based on what I'm reading here and in similar threads, it looks like the Koni sports on my current springs are the way to go (the springs show no signs of corrosion - it's a TX and FL car - no salt).

So William, Peter, Vas, anyone... would any of you suggest I look at anything other than the Koni's on current springs for my application? Here's my requirements:

- Mostly DD duty and lots of that with kids. So it needs to be comfortable on road.
- Occasional track and autoX (perhaps 5 total events a year), but not competing - just recreational. I'm not looking for absolute performance on track, just competence. Damping adjustability is a nice bonus since it allows some easy tuning at the track. But it's not essential.
- No desire for significant lowering/stancing. I'm happy at stock ride height, but could probably drop a half inch all around without beginning to scrape or bottom out on our subpar roads.

Any of you know if Koni's will be back on 25% off sale sometime in the next 4 months?

I would go with the Koni Yellows, Z4M FCAB, Z4M RTAB and Rouge Rear Shock Mounts. That is a proven combination of parts that is an improvement over the factory stuff while not sacrificing ride quality and improving the handing.

As far as lowering, I would leave the stock zhp springs unless you want the car lower.

Koni usually has their sale staring in March. I am waiting for it as well since the price of $500 for a full set of Koni Yellow shocks is very appealing.

Also do not forget about the other parts needed to do a refresh including the front reinforcement plates.

[san]

Great thread, guys! This has been very helpful to read through as I prepare to do FCAB's and RSM's soon. I got under the car last night to see what else needs to be replaced, and finally found the date code on the shocks. They're original. So at 99k miles and 11 years, I think they're due for replacement Based on what I'm reading here and in similar threads, it looks like the Koni sports on my current springs are the way to go (the springs show no signs of corrosion - it's a TX and FL car - no salt).

So William, Peter, Vas, anyone... would any of you suggest I look at anything other than the Koni's on current springs for my application? Here's my requirements:

- Mostly DD duty and lots of that with kids. So it needs to be comfortable on road.
- Occasional track and autoX (perhaps 5 total events a year), but not competing - just recreational. I'm not looking for absolute performance on track, just competence. Damping adjustability is a nice bonus since it allows some easy tuning at the track. But it's not essential.
- No desire for significant lowering/stancing. I'm happy at stock ride height, but could probably drop a half inch all around without beginning to scrape or bottom out on our subpar roads.

Any of you know if Koni's will be back on 25% off sale sometime in the next 4 months?

Based on your requirements, I think koni's are your best bet... (Others can correct me if I'm wrong)

I went with koni's myself and I'm happy with them. I am happy with ride and it doesn't feel harsh at all.

Regarding ride height I don't think shocks will affect your ride height, springs do. Since you are sticking other oem springs your ride height should remain the same...

I think koni's go on sale in March...


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[AggieBlake]

Yes, understood on ride height. I added that requirement to clarify that I'm not wanting significant drop, so that's not a reason for a coil-over set up. I'll stay stock ride height on these springs, but if I go with the Koni Yellows, it sounds like I could choose to go with a slightly sportier, shorter spring in the future (nothing dramatic, but a small drop).

I've already got the Rogue RSM's ready to mount, along with front strut tower reinforcements (no strut bar yet - need to save some cash) and power flex black FCAB's (a good friend with Bimmerworld suggested I try these). I'll add the Z4M RTAB's you mention (still considering Slater's suggestion of spherical RTAB's, but it'd be nice to save some coin if these are sufficient). Vas, did you add limiters to these Z4M RTAB's?

[slater]

So William, Peter, Vas, anyone... would any of you suggest I look at anything other than the Koni's on current springs for my application? Here's my requirements:

- Mostly DD duty and lots of that with kids. So it needs to be comfortable on road.
- Occasional track and autoX (perhaps 5 total events a year), but not competing - just recreational. I'm not looking for absolute performance on track, just competence. Damping adjustability is a nice bonus since it allows some easy tuning at the track. But it's not essential.
- No desire for significant lowering/stancing. I'm happy at stock ride height, but could probably drop a half inch all around without beginning to scrape or bottom out on our subpar roads.

Any of you know if Koni's will be back on 25% off sale sometime in the next 4 months?

konis should be on sale in march...

i think the konis are a great choice for your goals. here's what i would recommend:

- koni yellows from ground control; get their custom-valved rears, because they are less 'busy' and are also top-adjustable (otherwise you need to remove the rear shocks to make adjustments - personally, it's worth the extra money to me for this feature... time savings = money well-spent)
- rogue rear strut mounts
- BMW front strut reinforcement plates
- new swaybar bushings (poly works well)
- bimmerworld sealed spherical RTABs (quiet, OE bearing, allows rear trailing arm to articulate fully - they are sublime)
- Z4M FCABs are probably a good choice as they are more caster; i run AKG poly FCABs and i really like them, both performance and design)
- new rear outer control arm bushings (upper and lower); go for the OE upper 'bushings' (they are actually bearings) in both upper/lower locations (a la M3)
- also consider your rear diff mounts (rear is the most critical), and subframe mounts

that should make a pretty good driver. also, consider your alignment settings.



peter