[rice_smuggler]

I'm in the process of getting the last few bits for my suspension refresh for my 2011 328i xDrive (E92) and was wondering what my FCAB options are. I've read multiple threads also referring to these front arms as thrust arm/upper control arm/traction strut. As part of my parts list, I have brand new Lemförder arms (part #31126768983 & 31126768984).

Options for FCAB I've seen are:
1) Turner Motorsport Spherical Thrust Arm Bearing Set (E90, E91, E92 AWD, E84 X1) - can be purchased with or without arms
https://www.turnermotorsport.com/p-5...m-bearing-set/
2) Syncro Design Works e90, e92 335, M3 Front Control Arms - only 1 option to purchase arms with bushings installed as there is no option to purchase the bushings alone
https://syncrodesignworks.com/produc...nt=24380938435
3) STRONGFLEX Front wishbone bush xi 4x4 SPORT - only 1 option to purchase bushings, must purchase 2
https://strongflex.us/e90-e91-e92-04...553503470.html

Aside from these 3 options, are there any others?

[neilvan]

The E90 M3 thrust arm bushings work(You will have to press these into your stock arms though

Second option you listed
won't work as its for RWD applications

[iPee]

I have an E91 xDrive I purchased recently. Ordered the syncro arms and will be installing next week.

This the one you looking for if you have xDrive.

https://syncrodesignworks.com/collec...ro-thrust-arms

[bimmermech123]

Originally Posted by iPee

I have an E91 xDrive I purchased recently. Ordered the syncro arms and will be installing next week.

This the one you looking for if you have xDrive.

https://syncrodesignworks.com/collec...ro-thrust-arms

Did you install the syncro arms yet? If so how do they feel?

[vSOAPYv]

I have the adjustable powerflex in my 335i xdrive. Haven't touched them for 3 years. They only squeak when turned full lock. X drive cars have steel front control arms that can't be replaced with the ones from rear wheel drive cars.
https://www.powerflexusa.com/shop/pr...=1788#attr=505

Edit: If you already have the new arms with bushings installed why not just run them (FYI they need to be tightened with the car on the ground / with all the weight on the wheels). If you wanted different bushings, you should be fine to use your old arms and press in new bushings into your old arms. You can get bushing press / puller kits on amazon that will work. That's what I did.

[iPee]

Originally Posted by bimmermech123

Did you install the syncro arms yet? If so how do they feel?

Installed them yesterday. Night and day difference for me. Like tetsuo111 has mentioned no additional noise or harshness. He was the one who brought these to the community initially. The steering and input it feels a lot more alive. Hard to put the feeling into words.

A bit of background though, when I bought the car 1 of the bushings on the thrust arms were completely shot. Car came on BC Racing coilovers.

I replaced it with syncro arms. I also replaced the wishbone(control arms), outer tie rod ends, and ball joints that connect to the thrust arms. I also did an alignment as well. My car is at 188K km. While the change was significant for me there were also a lot of other factors at play. I'm not sure how much of it can be attributed to the Syncro arms but I love them so far.

Alignment before
Front
Caster (L/R) 8.1*/7.9*
Camber (L/R) -2.8*/-2.9*
Toe (L/R) -1.5*/-0.6*

Rear
Camber (L/R) -2.1*/-2.5*
Toe (L/R) -0.15*/0.25*

Alignment after
Front
Caster (L/R) 7.5*/7.4*
Camber (L/R) -3.0*/-2.8*
Toe (L/R) 0.05*/0.05*

Rear
Camber (L/R) -2.1*/-2.4*
Toe (L/R) 0.10*/0.10*

[bimmermech123]

Thanks for letting us know how the control arms affect the ride and handling as well as providing a detailed description of the circumstances of your particular vehicle. It is clear that monoballs are superior to any other bushing, with the only negative being the price.

I hope the alignment shop wasn't far from you, those before toe angles are absurd, but to be expected when doing such an upgrade.

[Peter Morrin]

Powerflex and Strongflex both make polyurethane bushings for the Thrust Arms of the xi. The Strongflex are a little cheaper. There have been some reports of squeaking from poly bushings, but some have obviously not had this issue. How do these compare with the m3 rubber bushing in terms of performance, durability, and NVH. I unfortunately can't afford the mono-ball suspension and would be concerned about NVH.

Peter

[Peter Morrin]

Update. I installed the Powerflex polyuerethane bushings in my thrust arms and rotated the eccentric bushing to provide maximum caster. 10,000 Miles since installation. There was no dicernable increase in NVH. I was also not able to discern any difference in steering response, but this was with snow tires in a 205/55-16 size. In summary, I am glad I went this route, but the ultimate performance option for those who are not in a snow belt would be the syncrodesignworks monoball fittings.

[chris55552]

Originally Posted by rice_smuggler

I'm in the process of getting the last few bits for my suspension refresh for my 2011 328i xDrive (E92) and was wondering what my FCAB options are. I've read multiple threads also referring to these front arms as thrust arm/upper control arm/traction strut. As part of my parts list, I have brand new Lemförder arms (part #31126768983 & 31126768984).

Options for FCAB I've seen are:
1) Turner Motorsport Spherical Thrust Arm Bearing Set (E90, E91, E92 AWD, E84 X1) - can be purchased with or without arms
https://www.turnermotorsport.com/p-5...m-bearing-set/
2) Syncro Design Works e90, e92 335, M3 Front Control Arms - only 1 option to purchase arms with bushings installed as there is no option to purchase the bushings alone
https://syncrodesignworks.com/produc...nt=24380938435
3) STRONGFLEX Front wishbone bush xi 4x4 SPORT - only 1 option to purchase bushings, must purchase 2
https://strongflex.us/e90-e91-e92-04...553503470.html

Aside from these 3 options, are there any others?

In same boat as you, same car as mine and im just starting to research my options. At first I thought I was screwed and couldnt upgrade anything but now Im seeing other upgrade xdrive cars suspension with success, Im not sure wheter to get coilovers, bilsteins or koni actives for my car plus the bushings and other components like you mentioned. Wish we had a list of all things we can upgrade...My problem is I dont know much about the different suspension components or which of the 3 shocks/struts coilovers would be best between the coilovers, bilsteins or koni actives.....Any suggestions you have would be great. Thanks for the information in the thread, gives me hope now.

[Peter Morrin]

Re: Shocks/Springs for E-90 x-drive

You will get different answers from different people depending on their set-up, driving environment, and personal preferences. Tire size and aspect ratio have a bigger impact on "ride" most other parts of the suspension. I personally avoid overly hard (delrin or aluminum) bushings due to potential NVH.

The x-drive platform is 10mm taller than the RWD platform and was likely targeted by the factory for more daily-driver conditions than the RWD versions. M Sport was the most focused version for performance (down from the M3). The factory engineers are pretty smart and have way more resources than any after-market tuner. When you change things from factory spec, understand what you are doing and the negative aspects you may be introducing (personal experience).

I run Continental DWS Plus in 225-45/17 on 8" wide rims in the summer. This is the factory "square" set up. I run 205-55/16 winter tires with the same suspension. If you still have run-flat tires, everyone says to ditch them.

I have the ST coil-over suspension in the front (height adjustable, fixed shock rate). I have the KV3 suspension (height adjustable, adjustable shocks) in the rear. Both were used when installed, so I don't have history from new. The height are currently set below M Sport height which is not desireable from a handling perspective, but I do not have any rubbing. I will be raising the vehicle to M Sport height.

The ST/KV rear shocks are prone to early failure. One of mine started leaking, hence the replacement with the KV3. When the current shock starts leaking I will look to replacing it with the Koni Yellows which are also adjustable. My guess is that the front shocks currently have about 40,000 miles and still seem to be fine and they salt our roads 4 months of the year.

I find the spring rate/shock dampening of the ST/KV coil-overs to be ideal for the x-drive sedan with the 17" tires. They are firmer than stock with less body roll, compliant, but not jarring. I can't compare them to any other after-market system, but they are less jarring than the M sport suspension in the E46 series with 18" tires.

I hope this gives some idea of one possible upgrade path. I would stick with Bilstein, Koni, KV, Ohlins and avoid BC and the cheaper options. This is one area where you get what you pay for.

[Runnin'Rich]

Originally Posted by Peter Morrin

Update. I installed the Powerflex polyuerethane bushings in my thrust arms and rotated the eccentric bushing to provide maximum caster. 10,000 Miles since installation. There was no dicernable increase in NVH. I was also not able to discern any difference in steering response, but this was with snow tires in a 205/55-16 size. In summary, I am glad I went this route, but the ultimate performance option for those who are not in a snow belt would be the syncrodesignworks monoball fittings.

Just to confirm - You are using RWD urethane eccentric bushings in AWD(xi xdrive) arms?
Not seen eccentrics for awd cars…

[Peter Morrin]

The Powerflex bushings are part number PFF5-5701. They press into the steel xdrive thrust arm/control arm at the joint with the sub frame. The hole for the bolt in the inner sleeve is ofset allowing it to be rotated for increased caster.

[Runnin'Rich]

Thanks for your reply Peter

How do you find the steering feel with the increased castor? Does the wheel have more force in returning to centre?

I remember liking the increased castor on my e36 Avus suspension with eccentric lollipop bushings

Checked out the fitting info for those powerflex bushings and was surprised to see that the OE position for the eccentric bushing is in the opposite direction.

I then started to think maybe the original xdrive bushings are also eccentric but in the opposite direction!!

Does anyone have one they could measure?

[Peter Morrin]

The photo from Powerflex is deceiving. The whole in the bushing is either centred or with added caster. I went with added caster, and honestly did not find a discernable difference in steering feel. On the positive side, there was no increase in NVH either.

If you do not drive on salted roads, and are willing to pay the price, the Mono-balls would be the way to go. I would buy them already pressed into new arms, so you don't have to remove the old bushing.

[kenmar]

Originally Posted by Peter Morrin

If you do not drive on salted roads, and are willing to pay the price, the Mono-balls would be the way to go.

What's the reasoning for this? Do the ball joints loosen up with bad roads and start to clunk? Or is it because of oxidation issues?

BTW, I've had yellow StrongFlex installed for close to a decade now and I'm happy with them. I did consider monoballs when I did the StrongFlex but didn't bc of the cost. My reasoning was that I could pay for a mechanic to do StrongFlex 3x for the same cost as 1 set of monoballs.

At about 150k km, my front end is slightly noisy on rough surfaces so I'm initiating a refresh this summer. It's possible that the StrongFlex could be the source of the noise, but they're last on my replacement list. Thus far, the biggest culprit so far has been the upper strut mounts. Moving onto the joints now.

[Peter Morrin]

Given the corrossion I see every spring, I am fearful of more complex mechanical joints (mono balls, heim-joints, non-sealed ball joints, etc) with the salt/brine/sand mixtures they apply to our roads in the winter. If these mechanical joints are well sealed with a rubber boot (like factory ball joints or cv joints) you are ok until the boot splits. I just don't think exposed joints have a good chance of surviving.

The urethane inserts appear to be a reasonable compromise between increased performance and longer life between OEM rubber bushings and Mono-balls.

[Leucosticte]

Originally Posted by Peter Morrin

Given the corrossion I see every spring, I am fearful of more complex mechanical joints (mono balls, heim-joints, non-sealed ball joints, etc) with the salt/brine/sand mixtures they apply to our roads in the winter. If these mechanical joints are well sealed with a rubber boot (like factory ball joints or cv joints) you are ok until the boot splits. I just don't think exposed joints have a good chance of surviving.

The urethane inserts appear to be a reasonable compromise between increased performance and longer life between OEM rubber bushings and Mono-balls.

The turner ball joints look sealed, so that might not be a concern for those ones.