[Littlebear]

Originally Posted by Lancelot

No worries, just sharing my unhappy experience as it could help others - make your own opinion and keep us posted
(Btw my wheels are stock too)

Will keep you posted. I want to take a trip to the mountains before bug season sets in, so soon!
For your case, I can only think maybe an alignment issue. Sometimes shops have a hard time aligning modded cars, or even certain BMWs, which give them a choice of specs depending on car equipment. Do you have an alignment printout from your M3 LCA days?

Murf

[Lancelot]

Damn you're going to make me try again :-/

With F8x LCAs:
Camber was -1°50' left / -1°23' right
Caster was 7°49 left / 8°19' right (quite a lot - hence the rubbing)

After changing back to stock LCAs :
Camber -0°39 left / -0°43' right
Caster 6°37' left / 7°01' right

[Littlebear]

The stock E46 was 5-something, and the E46 M3 was 7-something.

Murf

[Lancelot]

For reference too on 2 addicts, talks about rubbing too:
https://www.2addicts.com/forums/show...1250352&page=9

[Littlebear]

From what I'm reading, it seems wise to get the TS links in addition to the LCA links, in order to get the caster closer to normal F30 values.
But correct me if I'm wrong, the TS arms will increase camber to ~ neg 2 degrees (with rear ~ -1.6 -2.1)? Is this too much for the F30 chassis?
Lancelot, for the above alignment #s, did you have the M3 TS links in, or the normal F30 TS links, pls?

Murf

[Lancelot]

I had both, started with LCA only, added TS later on hoping to reduce caster, but that changes absolutely nothing, we compared both F8x and F3x TS side by side: no difference. And it was still rubbing after adding TS.

TS will not change camber at all, only caster, the BMW official repair manuals also mention alignment isn’t required when changing tension struts.

What you can try if caster (and rubbing) was a issue is to fit the TS with caster adjustable bushings (powerflex, superpro...), this would allow to reduce caster a bit and try to get back within more normal values.

[Littlebear]

Since this is a sway bar thread, I'm taking the LCA & TS talk to here:

http://f30.bimmerpost.com/forums/sho...6#post23124246

Murf

[Littlebear]

Hello BMW Experts!

We just got back from a 5-day trip to the ADK Mountains. All kinds of roads: truck rutted interstate, 4-lane parkway, fast 2-lane, slow 2-lane, & dirt! I even got stuck in mud up to the doors on a 'seasonal' dirt road. Had to dig myself out with hands & sticks (help was a loong walk away).
But the car felt great! The addition of the M-sport rear bar got rid of lots of unwanted movement back there. With an empty trunk, the car is very fast, balanced, & well matched to these North East roads. To my mind, the rear is still a touch soft (Bilsteins, M-Sport springs & bars), but that's sort of an old BMW tradition?

Murf

[lefthander]

Originally Posted by Lancelot

Look for threads about f80 LCA (lower control arms), there are plenty of references on the topic; i went there myself, and back. M3 LCAs are indeed providing added negative camber and the benefits of noticeably sharper turnin, however i got two major drawbacks from them
- high speed stability (~130km/h or 80mph) issues: car became so sensitive to crosswinds that it was dangerous whenever a wind gust or overtaking a big truck
- rubbing: these control arms move the wheel further front and started rubbing at the front of the wheel pit.

These arms are not made for f30 chassis, bear in mind that f30 and f80 subframes are completely different, unlike previous generations of 3 series.

The best way to get more camber is to swap the wheel hubs with the -0.5deg versions intended for f30s (and come as default to m135i/m235i), which respects the intended geometry of the car, other options are to be avoided in my opinion.

Is it because only you swap out the hydro bearing of f30 into f80?
Most, in fact all used the spacer but you went 1 step with the bushing change?

[sspade]

Originally Posted by lefthander

Is it because only you swap out the hydro bearing of f30 into f80?
Most, in fact all used the spacer but you went 1 step with the bushing change?

Which spacer are you referring to?

[lefthander]

Originally Posted by sspade

Which spacer are you referring to?

For m3/4 ts, most used spacers. I think lancelot replaced it with f30 bushings.

[Len_Beach]

M140i front arb question.

I managed to source M140i front and rear arb's from eBay.de before Christmas for a bargain allied to a 10% discount code.

These are intended for my F36 435d x-drive along with Bilstein B14s.

I've just realised when checking realoem that the front arb is listed under the F36 as fitting models with adaptive suspension only which my car isn't. Will this fit mine as the bar is listed as M140i 25.2/22.2mm?

Realoem also doesn't list arb bushes for the front for some strange reason. Any idea where these can be sourced from?

[Lancelot]

Originally Posted by Len_Beach

M140i front arb question.

I managed to source M140i front and rear arb's from eBay.de before Christmas for a bargain allied to a 10% discount code.

These are intended for my F36 435d x-drive along with Bilstein B14s.

I've just realised when checking realoem that the front arb is listed under the F36 as fitting models with adaptive suspension only which my car isn't. Will this fit mine as the bar is listed as M140i 25.2/22.2mm?

Realoem also doesn't list arb bushes for the front for some strange reason. Any idea where these can be sourced from?

Different bar diameters are designed with different car configurations in mind, Xdrives would typically have weaker front bars, rwd would have stronger ones; adaptive would have weaker bars than non adaptives...

I don't think there would be a problem fitting these, the only question is whether they're adapted to your chassis balance as they will affect understeer/oversteer behavior.

Lack of bushings for front arbs: it's normal they come glued to the front bar and cannot be sourced separately contrary to aftermarket bushings.

[Len_Beach]

Originally Posted by Lancelot

Different bar diameters are designed with different car configurations in mind, Xdrives would typically have weaker front bars, rwd would have stronger ones; adaptive would have weaker bars than non adaptives...

I don't think there would be a problem fitting these, the only question is whether they're adapted to your chassis balance as they will affect understeer/oversteer behavior.

Lack of bushings for front arbs: it's normal they come glued to the front bar and cannot be sourced separately contrary to aftermarket bushings.

Thanks for the swift response.

I've done some more research on my X-Drive bar and the M140i bar and the designs look different which is leading me to believe the front won't fit.

19458 is the X-Drive bar.

[mose121]

Just picked up a new F31 330i xDrive M sport with adaptive dampers. RealOEM shows a 13mm rear bar. Planning on adding ACS Springs + Dinan Shockwave and looking for ARB suggestions. Also, any reason why F80 bars won't work/aren't listed? I know just adding an OEM E9X M3 rear bar to non ///M model wagons was a popular mod. Not sure if the F8X bars don't fit the F3X due to the different subframes or if it's just that no one has tried it yet. If I can get away with just changing the F3X rear bar out with an F8X rear bar that would be preferable to having to deal with the front bar. I do not want to sacrifice too much ride quality either as my wife drives this car quite frequently as well.

[Lancelot]

Subframes are totally different so you really cannot fit F8x bars;
Fortunately we have 3rd party options too

My conclusion regarding bars is upgrade the front, leave the rear as is, fits my need for sharp front end and roll control, without really compromising ride quality.
Understeer isn't a concern for me as it wasn't really visible, and my LSD allows power oversteer when I need.

[D041987]

Just so everyone knows, you want some body roll. It pre-loads the tires and chassis to take corners faster. If you have no body roll you are going to slide and loose grip!. Chassis needs to move and settle in the corners and suspension will also need some movement to compress and work together. Going big and stiff to have NO roll is not the way to do suspension work.

[BMWILUVU]

Originally Posted by Lancelot

Subframes are totally different so you really cannot fit F8x bars;
Fortunately we have 3rd party options too

My conclusion regarding bars is upgrade the front, leave the rear as is, fits my need for sharp front end and roll control, without really compromising ride quality.
Understeer isn't a concern for me as it wasn't really visible, and my LSD allows power oversteer when I need.

F30 is already built to understeer and you are asking for more?

[GOLDENDUSt86]

How would it affect the driving if the bar is "too stiff"?

[Lancelot]

Too stiff would result in lower suspension independence, i.e. the ability for each wheel to make contact independently of the others

My experience is it resulted in imbalance over bumps for instance, so fine for smooth track but not for road.

Other aspect would be on hard cornering, your inside wheel(s) would lift more, reduce contact, and therefore result in understeer (front end contact surface reduced) or oversteer (rear end contact reduced); and then this affects FWD, RWD and AWD differently as it could impact power delivery; depends also if you have an LSD or not.

Well not a simple answer to this in my view those who provide over-simple answers to that are mostly wrong. Just my view based on personal feel.

[sspade]

Is it really a thousand dollar job to swap a rear bar on the F30 ?

Ive had an M240 rear bar in my garage for almost a year. Keep getting quoted stupid numbers to install so it keeps collecting dust.

It will be going on soon enough, just cant justify that money right now... especially not when Im in dire need of a Flash Tune

[cjlane]

Originally Posted by sspade

Is it really a thousand dollar job to swap a rear bar on the F30 ?

Ive had an M240 rear bar in my garage for almost a year. Keep getting quoted stupid numbers to install so it keeps collecting dust.

It will be going on soon enough, just cant justify that money right now... especially not when Im in dire need of a Flash Tune

Have you already done an upgrade to the suspension? You will get a huge break in labor if you were to do coils and the bar at the same time.