Improving Steering Feel with Aftermarket Front Control Arm Bushings?

[Coi]

I've owned by Z4M for several months and have been happy with it in almost every single way except for the steering feel. While it's better than any electric rack I've driven and certainly has some feedback, it's still not on the same level as the E93 I used to have or my buddy's low-mileage 987.2 Cayman. My car has 80k miles on what appear to be original FCABs. They do show some signs of wear/age but I don't think they're totally shot because turn-in is still precise and the car does not wander.

I was thinking of just replacing these with new OEM offset rubber bushings, but wondered if anyone saw improved steering feel with aftermarket polyurethane FCABs. I know the primary reason people upgrade these are to decrease deflection on track, but are they worth the downsides (noise, harshness) on a street car for better steering feel? I know there are many aftermarket posts about FCABs across various forums but I can't find one about how they affect feedback.

So these are the options I'm considering:

New OEM BMW rubber offset bushings (31107838575)
Could get them pre-pressed into the lollipops from somewhere

Whiteline caster bushing set, polyurethane (W52606)
https://whitelineperformance.com/pro...06-bushing-kit
I know this company is relatively reputable but I can't find any reviews of these bushings so that does give me some hesitation. Price is excellent.

Powerflex offset bushing, aluminum/polyurethane (PFF5-5601G)
https://www.powerflexusa.com/shop/pr...eccentric-3632
These are the most aggressive option being mostly aluminum, and are quite a bit more expensive. Some people report noise from these as well as an increase in ride harshness.

I know there are other factors that affect steering feel like alignment and tires (I have factory alignment specs and Michelin PS4S right now), but I figure if I'm replacing FCABs I should get the best option.

Thanks!

[Piper1]

Originally Posted by Coi

I've owned by Z4M for several months and have been happy with it in almost every single way except for the steering feel. While it's better than any electric rack I've driven and certainly has some feedback, it's still not on the same level as the E93 I used to have or my buddy's low-mileage 987.2 Cayman. My car has 80k miles on what appear to be original FCABs. They do show some signs of wear/age but I don't think they're totally shot because turn-in is still precise and the car does not wander.

I was thinking of just replacing these with new OEM offset rubber bushings, but wondered if anyone saw improved steering feel with aftermarket polyurethane FCABs. I know the primary reason people upgrade these are to decrease deflection on track, but are they worth the downsides (noise, harshness) on a street car for better steering feel? I know there are many aftermarket posts about FCABs across various forums but I can't find one about how they affect feedback.

So these are the options I'm considering:

New OEM BMW rubber offset bushings (31107838575)
Could get them pre-pressed into the lollipops from somewhere

Whiteline caster bushing set, polyurethane (W52606)
https://whitelineperformance.com/pro...06-bushing-kit
I know this company is relatively reputable but I can't find any reviews of these bushings so that does give me some hesitation. Price is excellent.

Powerflex offset bushing, aluminum/polyurethane (PFF5-5601G)
https://www.powerflexusa.com/shop/pr...eccentric-3632
These are the most aggressive option being mostly aluminum, and are quite a bit more expensive. Some people report noise from these as well as an increase in ride harshness.

I know there are other factors that affect steering feel like alignment and tires (I have factory alignment specs and Michelin PS4S right now), but I figure if I'm replacing FCABs I should get the best option.

Thanks!

Not sure how I missed your post and saw your post on the classics but in a nut shell feel is based on perception. Your M btw is hydraulic. Some will vouch and say yes. Some will say any feels better than worn. So if you base it off worn you truly won’t know your perception answer. If you did new oem then new poly that’d be your only true answer on how you feel it.

In a nut shell I believe the response feel with purple power flex is an improvement on non M. But that’s not the only aftermarket and change from oem to my front end suspension in direct relationship either. And I will say tire selection is key too in your response feel, if you’re on run flats ditch them. My 03 is on koni yellow adjustables eibach springs adjustable camber plates 255/35/18 toyo r1r along with the poly lcab and it’s a night and day difference than my e86 on stock suspension with Bridgestones. From steering response to feel of imperfections in the road so too have to ask your goals, track or daily and quality of roads you’re on. When it comes to nvh there’s more out of my camberplates than just the poly lcab

[ZeD4Mr]

I'm using whiteline.. They improved the turn in and sharpness.. I also have 265 front tires as well so nvh is not my concern.

[wdb]

I have an E93 and I can't say I notice a big difference between that and my Z4MC in terms of steering feel. The E93 seems to have sharper response, but the cars are different weights and shod with different tires so that might be subjective.

As for the Cayman, well, just fuggedabodit. You're not going to get anywhere near that with a Z4. I have a 996 and the steering feel reminds me of my old MGBs and Minis (real ones not the BMWs). P-cars with hydraulic racks are in a class by themselves.

All of that said, I like my Z4MC steering just fine. I'd recommend replacing with stock parts first. If that's not enough you can always swap in something more aggressive. Just don't expect to match that Cayman.

[lelandr]

I have the Condor LCAB, and they are good enough. How much caster are you running? Caster has a significant contribution to steering feel and straight-line stability. You're looking for something like 8deg or more. I feel that my steering is very tight with good feel. I have an E90 330i with shock, spring and M3 control arm upgrades, and the Z4 is better.

Make sure that all of your tie-rod ball joints are tight and that the rack doesn't have any slop.

Neither matches the feel in my manual steering E30 M3, but few cars do.

[ANILE8]

All rubber and polly bushings are a severe performance compromise.

Do it once and do it right.

Once you go Monoballs, you'll never go back.

[Beedub]

Originally Posted by ANILE8

All rubber and polly bushings are a severe performance compromise.

Do it once and do it right.

Once you go Monoballs, you'll never go back.

these are beautiful pieces....

do they do them offset?

[cbpip]

If your interested in the Turner Monoball FCAB I have a like new set that I can sell you. Less than 150 miles on them. Turner sells them new for 334.00 pre pressed in the Lolipops. Won't ship until July. Will sell mine for 285.00 shipped conus. If interested PM me. Went a different route with Rogue engineering units.
Also listed in classified section for sale.

[Michael9218]

The best FCAB replacement that I have found, that maintains the proper offset, is the Condor bushing.
https://www.condorspeedshop.com/coll...32481394229294

If you’re wanting better feel in the steering, you can adjust the pressure in the Z4M power steering pump. Lowering the pressure will give more feedback, making the steering feel more solid. Obviously lowering the pressure lowers boost, so more effort is required.

An excellent thread below provides information on our hydraulic steering systems. See post #5 for the DIY on lowering the PS pressure.
https://nam3forum.com/forums/forum/m...rmation-thread

[Coi]

Originally Posted by Piper1

Not sure how I missed your post and saw your post on the classics but in a nut shell feel is based on perception. Your M btw is hydraulic. Some will vouch and say yes. Some will say any feels better than worn. So if you base it off worn you truly won’t know your perception answer. If you did new oem then new poly that’d be your only true answer on how you feel it.

In a nut shell I believe the response feel with purple power flex is an improvement on non M. But that’s not the only aftermarket and change from oem to my front end suspension in direct relationship either. And I will say tire selection is key too in your response feel, if you’re on run flats ditch them. My 03 is on koni yellow adjustables eibach springs adjustable camber plates 255/35/18 toyo r1r along with the poly lcab and it’s a night and day difference than my e86 on stock suspension with Bridgestones. From steering response to feel of imperfections in the road so too have to ask your goals, track or daily and quality of roads you’re on. When it comes to nvh there’s more out of my camberplates than just the poly lcab

Thanks for the reply! I worded it poorly but I was trying to say that the hydraulic rack in my Z4MR is better than any electric rack but not as good as some other hydraulic racks. I agree that things like steering feel are extremely subjective and susceptible to placebo, but was hoping people like you who experienced swapping out their FCABs could share their opinion. Thanks!

The M never came with runflats and I currently have PS4S. They're not known for especially good feel but should be better than most and have excellent NVH properties. Sounds like poly FCABs aren't too much of a compromise though, which is also something I wanted to know.

[Coi]

Originally Posted by ZeD4Mr

I'm using whiteline.. They improved the turn in and sharpness.. I also have 265 front tires as well so nvh is not my concern.

Thanks for the reply! How are the whiteline bushings holding up and do you get any squeaking noise from them? I think I'll be going with the the whiteline offset FCABs since it seems like it isn't a massive compromise.

[Coi]

Originally Posted by lelandr

I have the Condor LCAB, and they are good enough. How much caster are you running? Caster has a significant contribution to steering feel and straight-line stability. You're looking for something like 8deg or more. I feel that my steering is very tight with good feel. I have an E90 330i with shock, spring and M3 control arm upgrades, and the Z4 is better.

Make sure that all of your tie-rod ball joints are tight and that the rack doesn't have any slop.

Neither matches the feel in my manual steering E30 M3, but few cars do.

I haven't had the alignment checked and was planning on getting a custom alignment done after swapping the transmission bushings over. Want to increase camber and caster in the front. Presumably my car is set to factory alignment specs from whenever the previous owner had the tires installed.

I don't feel any slop and the tie rods/ball joints seem good. Have checked with the car jacked up. I think the steering feel can be diminished by old bushings even if the ball joints are still good. Good to hear that your Z4M is even better than an E90. Mine was an LCI with the M Sport package and no aftermarket upgrades but I was impressed by the steering.

[Coi]

Originally Posted by ANILE8

All rubber and polly bushings are a severe performance compromise.

Do it once and do it right.

Once you go Monoballs, you'll never go back.

I think monoballs might be a little harsh for what's ostensibly a street car. I'm willing to put up with a little bit of a performance compromise so the car doesn't beat me up on rough roads. Also I have an M so need offset bushings. Those do look nice though!

[Coi]

Originally Posted by wdb

I have an E93 and I can't say I notice a big difference between that and my Z4MC in terms of steering feel. The E93 seems to have sharper response, but the cars are different weights and shod with different tires so that might be subjective.

As for the Cayman, well, just fuggedabodit. You're not going to get anywhere near that with a Z4. I have a 996 and the steering feel reminds me of my old MGBs and Minis (real ones not the BMWs). P-cars with hydraulic racks are in a class by themselves.

All of that said, I like my Z4MC steering just fine. I'd recommend replacing with stock parts first. If that's not enough you can always swap in something more aggressive. Just don't expect to match that Cayman.

While I found the feel of my E93 better, I still found the Z4M is more "responsive". The Z4 is a much lighter car and has a faster steering ratio with the same width front tires so there's more of a reaction from a smaller movement of the steering wheel. Both of my BMWs were completely stock suspension-wise. I did have cheaper tires (Firestone Firehawk Indy 500) on my E93 which I think are generally less refined than the PS4S on my E85 M. That may be part of it. I drove a mostly stock E92 M3 once and did find it got close to Porsche levels, especially in terms of road-feel on center. I might try the whiteline bushings since they're a less extreme (and less expensive) aftermarket option.

Also maybe I should have mentioned this but I owned an NC Miata between the E93 and the Z4M. Steering was a bit light for my taste and didn't load up like I want it to but those also have pretty good feel and great turn in. After having the Mazda an E9X M3 seemed so big and heavy and that's the reason I picked up an Z4MR instead.

[ZeD4Mr]

Originally Posted by Coi

Thanks for the reply! How are the whiteline bushings holding up and do you get any squeaking noise from them? I think I'll be going with the the whiteline offset FCABs since it seems like it isn't a massive compromise.

No squeaking at all and I only had about 1000 miles on them. So far so good. It actually feel more luxurious (If you can call that) than my worn out OE..