Baby BMW Forum banner
1 - 20 of 24 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter · #1 ·
Hi all,

3 months with my M140iX and already feel this is a car that either already does or has the potential to do most things very right for me, from boring daily commuting and school pick-ups, to weekend blasts and the occasional track-day (already did one in it). So that means green light for further mods (it's already running BM3 stage 1 and H&R springs and spacers) to sharpen its chassis without going too extreme as it still needs to be a daily car.

Now, my question is focused around the car being an xDrive as I have found several of the complaints online towards the rear-end being nervous and struggling for grip, to not apply on the xDrive. If anything, when grip is lost on the car (one has to really try to achieve this and only in DSC OFF mode) it feels very manageable and controllable and in reasonable doses it can actually help rotate the car and provide some extra rear wheel fun.

So am I right in guessing not all usual recommended mods would impact/work equally well a xDrive car?
M3/4 LCA, rear bushes, rear underbody bracing etc. What have other xDrive owners found to work best and in what order on these cars?

Obviously, suspension improvement should be universal so I'm guessing upgraded shocks in the form of B6 DampTronic would be a good move since I have felt a little bit more movement than I'd like under certain occasions even though the OEM adaptive do a good job for the most part, but what about the rest?
Tires are also up for a change soon although with winter coming up this will probably take place next spring.

Looking forward to your own findings/advice!
 

·
Registered
Joined
·
66 Posts
Probably not gonna find many xDrive owners here, but as I'm one of them I'll share what I can :)

LCA's don't work, I tried, but they didn't play nice with the drive going to the front. Don't remember what exactly was wrong, but they were taken off again 5 minutes after being put on so it was impossible.
I have the rear bushes, underbody bracing, quaife diff, antiroll bars, eibach springs and B6 damptronics, strut brace and PS4S's on 19" wheels that are 10mm further out, and I think each one of those upgrades is worth it. I did almost all of em at separate times, so I could feel each of them making a difference.
The B6 damptronics are a huge upgrade, and I would consider them an absolute must if you want to improve the car. Just be aware that comfort is harder than stock comfort, and sport is unusable unless you're on perfect asphalt. But the control is night & day. Probably there are even better options non-adaptive, but I didn't want to go that way.
The diff also is a huge upgrade, not so much in raw traction, but it still makes a very big difference in rotating the car under power. I never use DSC off, but even with ESP & xDrive it's very noticeable.
Bushes & bracing certainly also make a difference, not as noticeable, but with all of the things combined you certainly feel a lot more connected to the road. Just don't expect any single on of them to change your experience dramatically. Of course comfort isn't great, but I still think it's perfectly acceptable as a daily driver.
PS4S's I'm guessing will be an issue if you're on stock wheels, as they are/were only available in 19". I love em, but I will probably get the conti sportcontact 7 next time, just to see if I like those even more.

With all of this work done the ESP still light flashes from time to time when driven hard (hardly a surprise with 490hp on 245 tires) but it almost never really cuts power which I assume means the upgrades are doing a good job limiting the loss of grip.
I absolutely love mine, I doubt you can find many cars that are faster in the real world. However the RWD lovers here on the forums will all say it's boring, too efficient, not playful, less driver-oriented, less skill required etc etc... which may be true for them, but not for me. Just be aware that all the upgrades work to increase the efficiency, not the playfulness, make sure that's what you're after!
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #3 ·
Probably not gonna find many xDrive owners here, but as I'm one of them I'll share what I can :)

LCA's don't work, I tried, but they didn't play nice with the drive going to the front. Don't remember what exactly was wrong, but they were taken off again 5 minutes after being put on so it was impossible.
I have the rear bushes, underbody bracing, quaife diff, antiroll bars, eibach springs and B6 damptronics, strut brace and PS4S's on 19" wheels that are 10mm further out, and I think each one of those upgrades is worth it. I did almost all of em at separate times, so I could feel each of them making a difference.
The B6 damptronics are a huge upgrade, and I would consider them an absolute must if you want to improve the car. Just be aware that comfort is harder than stock comfort, and sport is unusable unless you're on perfect asphalt. But the control is night & day. Probably there are even better options non-adaptive, but I didn't want to go that way.
The diff also is a huge upgrade, not so much in raw traction, but it still makes a very big difference in rotating the car under power. I never use DSC off, but even with ESP & xDrive it's very noticeable.
Bushes & bracing certainly also make a difference, not as noticeable, but with all of the things combined you certainly feel a lot more connected to the road. Just don't expect any single on of them to change your experience dramatically. Of course comfort isn't great, but I still think it's perfectly acceptable as a daily driver.
PS4S's I'm guessing will be an issue if you're on stock wheels, as they are/were only available in 19". I love em, but I will probably get the conti sportcontact 7 next time, just to see if I like those even more.

With all of this work done the ESP still light flashes from time to time when driven hard (hardly a surprise with 490hp on 245 tires) but it almost never really cuts power which I assume means the upgrades are doing a good job limiting the loss of grip.
I absolutely love mine, I doubt you can find many cars that are faster in the real world. However the RWD lovers here on the forums will all say it's boring, too efficient, not playful, less driver-oriented, less skill required etc etc... which may be true for them, but not for me. Just be aware that all the upgrades work to increase the efficiency, not the playfulness, make sure that's what you're after!
You're right that not many xDrive owners are probably around with the UK-spec being what it is but where else can I find F2x xDrive info? That been said I couldn't have wished for a better reply than yours, having applied and tested all those upgrades I have been thinking about! expect to be contacted a lot in the coming weeks :p

I'm still couple of days from getting back home and addressing each one of the upgrades mentioned by asking for more info but I was too excited to not reply already and express my gratitude. Interesting what you mention about the LCAs, that's exactly the sort of feedback I was after regarding xDrive cars, as it was very high up on my list, together with the B6 about which I will need a bit more details on their impact on various roads and driving scenarios.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #5 ·
I'll do what I can to help, but I'm just a guy, not a car reviewer, so don't expect too much ;)

You mind if I ask where you're from?
It will be just fine! I'm based in Sweden, which also means nowhere near the amount of suspension/tuning specialists found in the UK. It's ok as I like to work on my cars but some mods needs pretty specialized equipment/tools I believe.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #6 ·
One question which I guess is not xDrive specific is the springs and shocks combo: My car came with H&R springs from the previous owner, I believe they quote 25mm drop (guessing from a stock 1-series height, more likely 15mm on a M140i ? ). I see a lot of people have gone with Eibachs or Motech springs and matched those to B6 shocks with great results so:

Would the B6 DampTronic work just as well with the H&R springs as they do with Eibachs? I know the H&R are supposed to be more aggressive than Eibachs so I wonder whether I should change to Eibachs if I choose the B6 or I can keep my H&R.
I definitely don't want to go B8 as they are anyway not adaptive and would not want to miss that feature, plus the added firmness from B6 to B8 would not be particularly welcome.
 

·
Registered
Joined
·
66 Posts
I've indeed also heard the H&R's are more aggresive (as in stiffer), so combined with the B6's which are also a little harder than stock, comfort won't be great, and handling on less perfect surfaces is probably also not as good as a result... for Belgium's crap roads eibach was definitely the way to go.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #8 ·
I've indeed also heard the H&R's are more aggresive (as in stiffer), so combined with the B6's which are also a little harder than stock, comfort won't be great, and handling on less perfect surfaces is probably also not as good as a result... for Belgium's crap roads eibach was definitely the way to go.
I don't worry so much about the added firmness (to an extent), I think this is primarily affected by the shocks characteristics so either Eibach or H&R the ride will stiffen when the B6 go on.
I mostly wonder whether H&R are on the limit (height-wise) of what can work well with B6 which are designed for OEM/OEM+ drop, as opposed to B8 which are meant only for lowered vehicles ( think something like 20-40mm).

Another struggle I have is wheels + tires combo. I guess it makes sense to go square setup? But OEM alloys are so damn narrow, especially fronts, that I can only run up to 235 so then I have to go aftermarket and run what? 8.5J with 245 tire all around?

Or maybe 245/35/18 front and 255/35/18 rear to move up a step at the back as well as otherwise the balance F/R (in tire width) changes too much with the square setup?
Never had a car with a staggered setup before so it's unknown territory what do I win/lose in each scenario... and how that applies to the xDrive in specific.
 

·
Registered
Joined
·
66 Posts
Plenty of people get the H&R's on stock dampers, I wouldn't expect it to be a problem on B6's as a direct replacement for those, but of course no guarantees ...

I have 8J with 245 all around and that works just fine. Belgian laws are pretty strict on changing spacing etc, so didn't want to risk going too wide at the back.
On the back you could probably go 8.5J & 255's, fronts I think you're limited but I'm sure many people here know more about that.

I don't think width really matters, unlike circumference which matters a lot (I tried changing only rears once as the fronts were still ok. Big nono.).
 

·
Registered
Joined
·
16 Posts
Recently bought an F22 M240i xDrive with adaptive M suspension and was very disappointed with the cornering performance using the original BMW rims with the 225/40 and 245/35 runflat Bridgestone S001 tires it came with from the dealer.

Due to the stiff shoulders of the runflats the turn in was initially pretty solid but it turned into an oversteer quickly with very little to no room for steering corrections, caught me off guard a few times when driving like I used to with my 130i M Sport on PS2 tires.

Based on feedback from Marco Polo and others here on the forum I‘ve switched to a 245/35 8J ET40 square setup with lightweight OZ Ultraleggera 8x18 rims and Goodyear Asy6 rubber which made the handling much more neutral and forgiving and in Traction mode the grip is just mind boggling.

This new setup solves a lot of things at once; better rubber, 28/24mm more track width front/rear, more rubber at the front, roughly 3kg less unsprung mass on each corner, less nervous “jumping“ of the front tires over small bumps, more comfortable drive and most importantly a much better looking car with arch filling wheels ;)

The adaptive shocks are apparently wider in diameter than the passive shocks but there‘s no rubbing whatsoever, I‘ve read that up front the wiggle room is less with 8.5J rims so the advice is to stick to the proven recipe with 8J rims.

With xDrive the diameters of the front and rear wheels need to stay within the 1.2% to prevent traction issues and damage to the drivetrain so the choices in 18” are limited to:
  • F225/40 & R245/35, 1.2% difference, factory standard
  • F235/40 ET45 & R265/35 ET50, 0.4% difference, highest sidewall of all the combos
  • F245/35 ET40 & R255/35 ET45, 0.8% difference, same setup as the new M240i xDrive with sport package
  • 245/35 ET40 square

I suspect the real difference of the factory setup is closer to the official 1% limit as the front is stretched making it smaller in diameter and rear tire balloons slightly making it larger in diameter but that’s pure speculation from my side.

From the factory the M240i already comes with the underbody brace installed and think also with slightly stiffer (rear?) springs so no need for any mods there at the moment but will keep track of this topic for other possible mods :)
 
  • Helpful
Reactions: mlcman

·
Registered
Joined
·
56 Posts
Discussion Starter · #11 ·
Recently bought an F22 M240i xDrive with adaptive M suspension and was very disappointed with the cornering performance using the original BMW rims with the 225/40 and 245/35 runflat Bridgestone S001 tires it came with from the dealer.

Due to the stiff shoulders of the runflats the turn in was initially pretty solid but it turned into an oversteer quickly with very little to no room for steering corrections, caught me off guard a few times when driving like I used to with my 130i M Sport on PS2 tires.

Based on feedback from Marco Polo and others here on the forum I‘ve switched to a 245/35 8J ET40 square setup with lightweight OZ Ultraleggera 8x18 rims and Goodyear Asy6 rubber which made the handling much more neutral and forgiving and in Traction mode the grip is just mind boggling.

This new setup solves a lot of things at once; better rubber, 28/24mm more track width front/rear, more rubber at the front, roughly 3kg less unsprung mass on each corner, less nervous “jumping“ of the front tires over small bumps, more comfortable drive and most importantly a much better looking car with arch filling wheels ;)

The adaptive shocks are apparently wider in diameter than the passive shocks but there‘s no rubbing whatsoever, I‘ve read that up front the wiggle room is less with 8.5J rims so the advice is to stick to the proven recipe with 8J rims.

With xDrive the diameters of the front and rear wheels need to stay within the 1.2% to prevent traction issues and damage to the drivetrain so the choices in 18” are limited to:
  • F225/40 & R245/35, 1.2% difference, factory standard
  • F235/40 ET45 & R265/35 ET50, 0.4% difference, highest sidewall of all the combos
  • F245/35 ET40 & R255/35 ET45, 0.8% difference, same setup as the new M240i xDrive with sport package
  • 245/35 ET40 square

I suspect the real difference of the factory setup is closer to the official 1% limit as the front is stretched making it smaller in diameter and rear tire balloons slightly making it larger in diameter but that’s pure speculation from my side.

From the factory the M240i already comes with the underbody brace installed and think also with slightly stiffer (rear?) springs so no need for any mods there at the moment but will keep track of this topic for other possible mods :)

Another very helpful post and (hooray) another Mx40i xDrive owner sharing their experience!

I very much agree with the findings from your OEM alloys and tires, it is exactly what I have felt with mine: Direct and responsive turn-in, which then seems to become mild understeer but keep pushing and it quickly turns to oversteer, provided the ESP is set to Sport+ or DSC OFF. With ESP left alone it will just cut power accordingly so I assume you were referring to Sport+/DSC OFF scenarios? Anyway, the transition to oversteer is indeed very quick and I thought it was purely my lack of previous RWD experience (go-karting not being accounted for :p ) that made it feel so, you definitely need to be able to move your hands quickly otherwise you're into trouble, but maybe it's indeed how the OEM setup is.

So, 8J paired with 245 tire all-around seems to be the way for 18" which I plan on sticking with. I just wondered whether 255/35 made sense for the back as it would be a smaller F/R difference in circumference than even the OEM setup and you get more rubber at the back which is primarily driven, but you then need to move to 8.5 rear alloys and you can't swap tires obviously.

Incidentally, Asymmetric 6 is the tire I'm thinking of too, my only worry is whether this change (either 245/245 or 245/255 on Assys) would take away the current playfulness of the car for the sake of grip and efficiency. It's my first car where the rears are constantly, and not on-demand, being driven and I do enjoy the silly slide every now and then when conditions allow. And for the most part, I would say that the car does not lack traction even with the stage 1 torque, unless you're really trying...
 

·
Registered
Joined
·
16 Posts
My favorite B road setting is TRACTION mode as I live in the countryside and many of the roads here are pretty rough with lots of cracks and potholes, lots of speedbumps and I have to go off road with two wheels regularly to make room for trucks and heavy farming equipment.

Not sure if you meant TRACTION / DTC mode with DSC OFF but the former is set by single pressing the DSC OFF button (instead of a long press) which switches the default oversteering inducing dynamic stability control (DSC) to a dynamic traction (DTC) mode with a comfort suspension, steering, throttle response and also opens up the valves completely for maximum exhaust sounds. Its the hidden party mode for casual active driving with the windows open and combined with xDrive you really need to do your best to loose traction with proper rubber.

The choice to go to 245/35 allround is that my Bimmer will be used for B road roadtrips in Europe and prefer the convenience of bringing just one size spare tire over maximum rear grip as I had zero rear traction issues with the standard wheels. If the built was to be more track oriented then I would probably go for the wider rear tires as on track you will probably turn DSC off completely and tune the B58 for more power so need more mechanical grip.

Trick is finding good rims with the proper ET when going for the 245/255 setup, could only find the BBS CH-R with 8J ET40 for the front and 9J ET44 for the rear. Another option is brands like Bola and 2Forge which use blanks from Taiwan and finalize them in the UK to order in custom ET values, the latter seems to be more used on track.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #13 · (Edited)
My favorite B road setting is TRACTION mode as I live in the countryside and many of the roads here are pretty rough with lots of cracks and potholes, lots of speedbumps and I have to go off road with two wheels regularly to make room for trucks and heavy farming equipment.

Not sure if you meant TRACTION / DTC mode with DSC OFF but the former is set by single pressing the DSC OFF button (instead of a long press) which switches the default oversteering inducing dynamic stability control (DSC) to a dynamic traction (DTC) mode with a comfort suspension, steering, throttle response and also opens up the valves completely for maximum exhaust sounds. Its the hidden party mode for casual active driving with the windows open and combined with xDrive you really need to do your best to loose traction with proper rubber.

The choice to go to 245/35 allround is that my Bimmer will be used for B road roadtrips in Europe and prefer the convenience of bringing just one size spare tire over maximum rear grip as I had zero rear traction issues with the standard wheels. If the built was to be more track oriented then I would probably go for the wider rear tires as on track you will probably turn DSC off completely and tune the B58 for more power so need more mechanical grip.

Trick is finding good rims with the proper ET when going for the 245/255 setup, could only find the BBS CH-R with 8J ET40 for the front and 9J ET44 for the rear. Another option is brands like Bola and 2Forge which use blanks from Taiwan and finalize them in the UK to order in custom ET values, the latter seems to be more used on track.
I meant either Sport+ mode or DSC OFF mode, I have induced power sliding in both of those modes although in Sport+ it's harder and lasts a shorter time, whereas in DSC OFF (4sec press) you can basically throw the rear out at every low/medium speed corner. It's my go-to mode when I know I can have some fun along the way. I don't use Traction / DTC (single press) but probably because I haven't experimented with the different combinations of suspension/throttle enough yet. To my (limited) knowledge the dynamic behaviour of TRACTION / DTC is the same as Sport/Sport+ but it allows wheel-spin on top? (aside from the lighter suspension/steering etc.)

Back to tires, I hear you about the practicalities of 4 identical tires, but unfortunately B road trips to Europe are not something I could do in the near future, sounds awesome though... I do plan on visiting my local track 2-3 times a year (already did one track-day so far) so maybe 255 at the back makes some sense although I don't see myself turning this car into a track-day tool, just after some full-on driving under the regulated and controlled conditions of a closed circuit.

I just worry, as I already said, whether the move to 245/255 will make the car too grippy and clinical. I do enjoy the current level of playfulness and how easy it is to slide it around with DSC OFF, I wouldn't want to turn it into a Golf R (been there :LOL: ) so maybe 245/245 is the way.


PS. I could run 255 with 8.5J no? doesn't need to be a 9 as far as I'm aware?

PS.2 Some further feed-back on the Asymmetric 6 please? Turn-in/road feel/comfort/noise? :)
 

·
Registered
Joined
·
16 Posts
To my knowledge TRACTION mode is like Sport+ with comfort settings, you can check the table here:

Check Tyre Reviews review of the Asy6 and PS5 here:

Was about to order Michelins by default but after seeing the review I went for the Goodyear for the sportier handling, 3db less noise and the fat rim protector and am very pleased so far with the turn in, grip, comfort and roadnoise (the latter was really annoying with the runflats).

255 is the max size for 8.5J as 245 is the max size for 8J.
 
  • Like
Reactions: mlcman

·
Registered
Joined
·
56 Posts
Discussion Starter · #15 ·
A thought I had the other day when I had to visually check whether I was on Comfort or Sport (didn't feel as firm as I thought it should be, yet I was indeed in Sport):

Since the range of firmness is rather limited it seems, maybe a passive setup like B8's makes more sense since it comes at almost half the price of B6 DampTronic? Or I will end up cursing every time I'm not on perfect tarmac?
 

·
Registered
Joined
·
66 Posts
Can't answer that question, I can just say that on imperfect roads there is no mistaking comfort for sport or the other way around with the B6's ...
The only time I ever had to check was a roadtrip in Norway, there it was permanently in sport and still perfectly comfortable.!
 

·
Registered
Joined
·
231 Posts
I don't have an X drive, but I am interested in upgrading the stock adaptive suspension on my M240i. I think every single person I've seen comment on their adaptive B6 (both in the UK and the USA) has said this setup is an improvement on stock but that 'Sport' mode becomes unusable on anything but perfect tarmac such as a motorway, where it seems to me that upgraded suspension isn't needed anyway. I've started to wonder if a Bilstein B4 adaptive setup is worthy of serious consideration, from the point of view that I assume the 'Sport' mode would be softer and therefore usable, and although the response may not be as good as B6 in the right situation, it would still be a worthwhile upgrade and therefore a reasonable compromise. Otherwise I'm thinking a Bird's passive setup may be the way to go.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #18 · (Edited)
Can't answer that question, I can just say that on imperfect roads there is no mistaking comfort for sport or the other way around with the B6's ...
The only time I ever had to check was a roadtrip in Norway, there it was permanently in sport and still perfectly comfortable.!
Do I read this right that the firmness range is broader with the B6 compared to the stock setup? Or you also felt there was noticeable difference between Comfort/Sport even on OEM dampers? Because to me the difference currently is rather small. Comfort still feels rather controllable, and Sport is deifnitely not punishing and also shows body lean when speeds rise. It's mostly on broken pavement and going over speed bumps that I realise which mode I'm in.

Compared to say a Golf GTI, where Comfort is pretty soft and Sport firms up noticeable.

I don't have an X drive, but I am interested in upgrading the stock adaptive suspension on my M240i. I think every single person I've seen comment on their adaptive B6 (both in the UK and the USA) has said this setup is an improvement on stock but that 'Sport' mode becomes unusable on anything but perfect tarmac such as a motorway, where it seems to me that upgraded suspension isn't needed anyway. I've started to wonder if a Bilstein B4 adaptive setup is worthy of serious consideration, from the point of view that I assume the 'Sport' mode would be softer and therefore usable, and although the response may not be as good as B6 in the right situation, it would still be a worthwhile upgrade and therefore a reasonable compromise. Otherwise I'm thinking a Bird's passive setup may be the way to go.
From related discussions on previous cars, I had the impression B4's are very similar with OEM in terms of characteristics, and any improvement is minor, if any. Considering the cost I would only imagine they'd be an option when OEM dampers are on their way out and one wants to fix the suspension with a quality item with better warranty but not when a more sporty ride is in mind, would be glad to hear from anyone who has them on their adaptive M140i though.
 

·
Registered
Joined
·
66 Posts
It's all down to road quality of course, I clearly felt the difference on stock as well... But I would say B6 comfort is a little firmer than stock, and B6 sport considerably firmer than stock. I'm sure it's still perfectly acceptable from the pov of vehicle dynamics, but it sure doesn't inspire confidence if you feel like you're bouncing down the road.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #20 ·
It's all down to road quality of course, I clearly felt the difference on stock as well... But I would say B6 comfort is a little firmer than stock, and B6 sport considerably firmer than stock. I'm sure it's still perfectly acceptable from the pov of vehicle dynamics, but it sure doesn't inspire confidence if you feel like you're bouncing down the road.
Generally the roads are quite smooth around here I'd say, they may be old and noisy but there's minimum broken tarmac, potholes, patches etc. which is why I easily drive in OEM Sport+ almost the entire time and I have a feeling the B6 would be just fine.

Your last sentence referred to stock behaviour (ie. driving in Comfort and feeling the car is too loose?) or being in Sport with B6 dampers on bad tarmac and feeling the car becoming unsettled everywhere?
 
1 - 20 of 24 Posts
Top