[23109VC]

After reading several members posts on this mod, I bit the bullet and did it.

I found a set of F90 competition sway bars off of eBay. Mine came off a 2019. My M550 is a 2018. The fit perfectly.


My thoughts after having the bars in for a day - GREAT MOD!!

It’s not going to make your G30 handle like a 718 Cayman/Boxster, but you WILL feel a difference.

The first thing I noticed when I pulled away from the shop, is the ride felt a tad bumpier. Even at low speeds, just rolling along surface streets at 25-35mph….it felt slightly firmer. I only noticed that in sport or sport+ mode. In comfort mode it feels just like stock. Keep in mind, this is a very small change, maybe 10%. Just enough that I can feel it, but not a lot. I’d say sport now feels like in between the old sport and sport +. But comfort still feels like comfort. So it’s a win win - my sporty settings feel sportier, but my comfort setting feels the same.

The other thing that surprised me is the steering wheel feels firmer and tighter. When I initiate the turn, the car feels more responsive like there’s less sloppiness in the steering. A more direct feel, with better turn in. I noticed that even at slow speeds. I think this feels much better. It’s not a bad firmness - it’s good - the steering feels more immediate and the on center vagueness is reduced.

As far as cornering, it *definitely* keeps the car flatter in turns. I can feel it at both lower speeds and at higher speeds. Just driving around normal city streets when I make a low speed turn, I don’t feel the whole car leaning over the same way it used to. My M5250 always felt soft to me even at low speeds turning around corners, I’d kind of feel the whole body slightly sway. That is greatly reduced. I had an opportunity to take one 90° turn at a pretty good pace..nothing illegal… but spirited for sure. the car handled noticeably better. Turned in tighter and held the line better with less sway.

Overall impression - I’m not signing up for a track day… don’t get me wrong - the car is still a 4600lb sedan - BUT - it’s well worth doing if you think your car feels “soft” and you want to tighten things up with no downsides.

total cost: Sway bars on ebay - $450 shipped. Labor $190. Less than $650 out the door. Well worth it!!

I really don’t see or feel any downside to this mod. You do lose the vibration dampener that is attached to hte rear sway bar.so maybe the increased vibration I picked up on is from that? That thing is affixed to one of the brackets, and that bracket will not fit around the M5 bar, so you have to use hte donor cars brackets. the brackets on the FRONT bar are the same part number - so M550 front sway bar brackets work. But as i said - the increase in vibration is MINIMAL and I did not even feel it in comfort mode.

If you are on the fence about this mod and can spend the money - DO IT!

[23109VC]

Had a chance to take the car out for another drive and get a better feel for how it performs with the F90 comp sway bars.

I finally got to zip around a long cloverleaf freeway on-ramp. This one is a right handed that is a slight downhill…rotates a full 270 degrees and feeds you onto the freeway… once you get to the lower portion it’s mostly flat… it’s a great turn that really lets you feel the cornering ability of the car.

Previously, I always felt like the car was leaning way over and when I woudl get to the bottom as the turn was about to straighten out - it took the car a second to flatten back out and compose itself.

This time it felt like the car was quite a bit flatter throng the entire turn - allowing me to carry a bit more speed through teh turn, and at the very end, as I was at peak g forces - it felt like the front end was much more planted on the pavement and way less body roll..as if the car was turning tighter and biting harder into the turn.

It’s still heavy luxury car… I’m sure a 718 Cayman woudl rip my headlights out and pull away on the entire turn…BUT…. The difference in handling is significant. Well worth the money I spent. This is a no brainer if you think your M550 has sloppy handling. It doens’t make it an M5… but it sure helps a lot!

[Weekend Warrior G30]

Thank you for posting this. I have a set I am going to install soon, I want to see how they pair with KWV3 coilovers

[23109VC]

Originally Posted by Weekend Warrior G30

Thank you for posting this. I have a set I am going to install soon, I want to see how they pair with KWV3 coilovers

Awesome! I have had plenty of time to evaluate this mod and it is 100% positive. The ONLY negative I can report is more vibration. On the freeway in sport or sport +mode, where the dampers on my car are in a stiffer mode, you can feel more bumpiness in the ride than when it was stock, but I woudl not consider it to be significant. If you want your car to be “ultra” comfy, don’t do this mod, as there is an increase in stiffness and vibration.

At the same time, if you put the car in comfort mode that increased stiffness seems to go away 100%.

I like the increased stiffness in steering as the car feels more planted and the steering is much more direct. You feel like the car responds more quickly to steering inputs. The car overall still retains its luxury feel, but you get flatter cornering. On long circular on-ramps the car is much flatter and you can push it harder through turns which is good.

the car is not as flat as a G80 M3 or M3/M4. I have driven a G80 M4 and an F90 M5 adn those care are a different animal. The change with the F90 bars is not “transforming” and it’s not going to change your car into a canyon carver, but it does significantly make the car more fun in the turns and more capable on tight turns.

This is a no brainer mod if you would like to improve the handling of your G30. It’s an easy direct bolt in mod and my local speed shop did the install in like an hour. Easy. I paid $190 for install.

Given how cheap you can get these bars on the used market and how cheap they are to install it’s a worthwhile mod.

If you want something that tears up the twisties - the M550 is just not the car for that no matter what you do to it. My Cayene GTS, bone stock, is way more raw and better handling than the M550…so that somewhat detracts from the experience in the M550 as I constantly have a reminder of what it “could” be like… i will probably eventually upgrade my m550 to some thigh else - like a G80 or a 911. But in the meantime, this mod has made my M550 much better.

If you are on the fence do it.

[Weekend Warrior G30]

So I installed these f90 m5 competition sway bars today on my 540i sportline. These bars really compliment the kwv3 coilovers. The car feels extremely stable flat and balanced. The steering is sharp and direct and the car feels overall more planted. This is cheap upgrade that can be done in an afternoon that directly changes the feel of the car.

[tsbrown]

Would these work on 540i M sport with 704 static sport suspension? I specifically opted out of the adjustable suspension when I ordered the car because there was little difference in settings on my E90 M3 and my F30 340i was either too stiff or too floaty. The static suspension has been great but it allows too much body roll.

[Weekend Warrior G30]

Originally Posted by tsbrown

Would these work on 540i M sport with 704 static sport suspension? I specifically opted out of the adjustable suspension when I ordered the car because there was little difference in settings on my E90 M3 and my F30 340i was either too stiff or too floaty. The static suspension has been great but it allows too much body roll.

Yes, I opted out of any electronic suspension because I wanted to modify the suspension. F90 comp sway bars would be an easy swap for you.

[Marc_911]

Did the M5 comp on my 21 M650 today, bars can be found cheap. Much bigger improvement than I expected, great mod for the money. Highly recommend. Not like my 911 but huge improvement.

[Drifttime85]

Anyone know if this set fits the m550?

dinan sway bars

I noticed people finding f10 sways on eBay.

[tjbuggy2b]

23109VC Since you said you there is a difference in feel between comfort and sport, I assume you have active suspension? Curious how this feels on non-active suspension. Will it just feel like sport mode all the time?

[23109VC]

Originally Posted by tjbuggy2b

23109VC Since you said you there is a difference in feel between comfort and sport, I assume you have active suspension? Curious how this feels on non-active suspension. Will it just feel like sport mode all the time?

That’s a great question my M550 did have adaptive suspension so on the regular suspension I’m assuming everything just stiffens up slightly.

The change in stiffness was not that drastic. I noticed more stiffen up in the steering response and cornering, but the ride was pretty much the same maybe tend to 20% stiffer at most. It’s not like the car suddenly became bouncy and bone jarring. I don’t think a significant other In the passenger seat would notice the difference

[Tpriest7893]

Originally Posted by Weekend Warrior G30

So I installed these f90 m5 competition sway bars today on my 540i sportline. These bars really compliment the kwv3 coilovers. The car feels extremely stable flat and balanced. The steering is sharp and direct and the car feels overall more planted. This is cheap upgrade that can be done in an afternoon that directly changes the feel of the car.

So I could add these on my 540i M sport? Its stock suspension and I don’t plan on touching suspension. My car still has factory warranty so I wonder if bmw would throw any fits

[co_pa]

Hey 23109VC
I've gone through all your posts on this topic; coming into my LCI M550i myself from a lowered G20 M340ix (and lowered F10 M5 and F80 M3 Comp before that) and looking to get some of that sharpness back, less body roll, etc.

Did you source the same part #s that Matadore did on your M550?
Front sway bar - 31357856911
Rear sway bar - 33557856913 & rear swing support - 33506869096.

I can't find M5 Comp specific part #s so assume so? Do you need just one rear swing support? Any other parts and pieces to source?

My plan is to order ASAP and install w/ Dinan springs.

Appreciate you documenting your experience and sharing your parts list!

[co_pa]

Originally Posted by Marc_911

Did the M5 comp on my 21 M650 today, bars can be found cheap. Much bigger improvement than I expected, great mod for the money. Highly recommend. Not like my 911 but huge improvement.

Hey Marc_911 Per my post directly above, I'm looking to confirm part numbers and the "must have" parts list to switch out my M550 stabilizer bars. Only finding reference to the PNs I've listed. Appreciate any confirmation or insight you or others with M550s might have to add. Thx

[Drifttime85]

Keep me posted on this as well. I think this is the next mod on my list.

[ZadoEsq]

Originally Posted by Marc_911

Did the M5 comp on my 21 M650 today, bars can be found cheap. Much bigger improvement than I expected, great mod for the money. Highly recommend. Not like my 911 but huge improvement.

Maybe I missed something, but I didn't know there was such a thing as an M650. Did you mean an M850?

[gizmonder]

I tried M5 sway bars on my M550i. I think this mode is nonsense, if you don't drive track.
You lose in comfort on bumpy road and it's hard to feel difference during daily driving. You need to drive like a crazy to see real difference.
It provides less understeer. Steering is heavier (can't understand why) and provides little bit more feedback. Body roll is almost the same.
But this changes don't cover comfort lose.