[bmw_solid]

Hi All,

Hope you are well.

Had the above car for over a year now and great car but only have one complaint - why does this car feel like its on M-Sport suspension?!

I have the 230 LA Wheels 19" and no run flats front 225/35 and rear 255/30 as per OEM spec.

Due to 2 leaking shocks, I had all 4 shocks replaced (fronts are non-sport SACHS and rears are non-sports Bilstein B4s)

+ New Lemforder strut mounts, new SACHS non-sport bump stops, new Febi control arms and wishbones

Along side the new B4s at the rears, I had new non-sport Febi bump stops and Febi upper mounts also.

I have 2 symptoms/problems with the ride/comfort and I can't find to convince myself that the car drove like this out of the factory!

1) At the front there seems to be a lot of 'thuds' and crashyness over medium to large bumps and they sound quiet heavy and deep (like a heavy box jumping up and down in the boot) as opposed to clunks or metallic noises. These 'thuds' are not heard in the rear...only the front.

2) When going over medium to heavy bumps the rear of the car feels very firm, like M-Sport firm, and can sometimes give a back ache because on city roads there are bumps everywhere. The fact that my car has M-Sport seats doesn't help either!

I have original BMW springs all round - I think C7 at the front and C2 at the rear and I understand these are non-sport BMW springs.

My ride heights (fender to centre of wheel cap) are 15" at the front and 14" at the rear so front sits 1" higher than rear and this is normal I think. Can anyone confirm their E92 SE ride heights?

I am running 10% lower air pressure for more comfort and less thuds - this improves the ride to a level where I can live with the car and enjoy it! However, after about a day of driving, the ride seems to get worse again as the tyre pressure increases. I filled the pressures yesterday (cold start) at 32 psi front and 36 psi rear (spec says 36 front and 40 rear) and after driving for about 15 minutes I re-checked the pressures and had 34 at the front and 40 psi at the rear! So this increase in pressure hugely affects the ride comfort of this car because it feels like an M-Sport again! Driving the car at specified pressure is way too stiff for a SE model!

So, assuming my ride heights are okay I take it the springs are not that bad and not sagging.

I know the 10% lower air pressure can help but this seems to be a temporary solution as the increase of tyre pressure with time makes the ride firm again.

So, the only last thing that comes in my mind is to trim the rear bump stops or install some aftermarket rear upper mounts?

I came across this thread ( https://www.e90post.com/forums/showthread.php?t=836365 ) but the OP didn't give detail on how much material he cut off the bump stops.

I was suggested cutting off 5mm by a fellow member on this forum but am wondering how effective 5mm would be in terms of comfort. Can I cut off something along the lines of maybe 10mm without risking the internals of the rear shocks?

Or, I have heard about dinan or monroe mounts which act as a spacer and provide more suspension travel. Can someone advise if this is a sensible option for a E92 SE 100% stock car?

Finally, what is the secret behind the firm and thuddy ride characteristics of this E92 SE?! Does it have some 'upgraded' shocks or springs which perform like M-Sport but are actually classed as SE shocks/springs? Is the E92 lower than the E90?

I can't imagine of owning a Pre-LCI E9x M-Sport given the way my car drives! How do you pre-lci E9x M-Sport owners cope with your car in terms of comfort?! I know they must be great to drive but does it offer any comfort? Is the sacrifice of M-Sport handling worth the reduced comfort?

Members on this forum keep telling me these cars are meant to drive like this and they are crashy over bumps etc etc. But I find it hard to accept that these car drove like this when they came out the factory! Because if they did, most customers would either bring the car back saying there is something wrong or simply return the car IMO! I understand BMWs are more firmer than Mercs but that does not mean they can't get their cars to have good dampening of bumps and thuds - the whole point of buying a BMW IMO is to experience that trade mark handling with decent levels of comfort...

Tbh, I am a bit gutted as the whole front suspension (struts, arms etc.) have been replaced with new good quality stuff but I am still at square 1

Hoping someone can help.

[streetpro]

I would suggest to upgrade to R17 or 18 lightweight wheels as it has an significant effect on the ride quality (lower un-sprunged mass along with more tire sidewall).
I ride preLCI e92 335i with M3 arms and roll-bars, M springs, new Sachs M shocks and the ride is quite plush, definitely not jerky or harsh... I even have a 10mm lower front shocks top mount, car sits pretty low but still very enjoyable even in the city...
and I run 8x17 oem winter 225/45... plus 8x18 Leggeras summer 235/40

However to your question - cutting of 5 mm will result in no change, at least 15mm or simply change to M bump stops... fe1rx has an excellent write up on how the rear suspension reacts to the oem bump stops (in reality the rear already rides on the tip of them when static). To have comfy suspension you want as much as wheel travel as possible along with reasonable tough spring rate (progressive Eibach) and matching dumpers (it is crucial, as many people have learned the hard way, incl. me, that e.g. Eibach is no go with Bilstein B8, as it ends up being too tough/harsh and not compliant - shaky ride at low speed).

[bmw_solid]

Originally Posted by streetpro

I would suggest to upgrade to R17 or 18 lightweight wheels as it has an significant effect on the ride quality (lower un-sprunged mass along with more tire sidewall).
I ride preLCI e92 335i with M3 arms and roll-bars, M springs, new Sachs M shocks and the ride is quite plush, definitely not jerky or harsh... I even have a 10mm lower front shocks top mount, car sits pretty low but still very enjoyable even in the city...
and I run 8x17 oem winter 225/45... plus 8x18 Leggeras summer 235/40

However to your question - cutting of 5 mm will result in no change, at least 15mm or simply change to M bump stops... fe1rx has an excellent write up on how the rear suspension reacts to the oem bump stops (in reality the rear already rides on the tip of them when static). To have comfy suspension you want as much as wheel travel as possible along with reasonable tough spring rate (progressive Eibach) and matching dumpers (it is crucial, as many people have learned the hard way, incl. me, that e.g. Eibach is no go with Bilstein B8, as it ends up being too tough/harsh and not compliant - shaky ride at low speed).

Interesting about your 335i M being comfy/enjoyable in the city. About every other person on this forum keeps saying the E9x is crashy and has flawed suspension! (which I don't believe these cars were like this when new).

I know 17" would be great but really like the look of the 230 LA 19" wheels.


Won't cutting off 15mm be dangerous for the rear shocks in terms of shock travel and bending the internals? Are M bump stops smaller? And aint the M bump stops meant to be firm when compressed? Will look into fe1rx's write up.

I have B4 non-sports on the rear and these are new and I don't have a budget to go for expensive shocks! I know there are some great stuff out there but they have a very hefty price tag!

[The Nightman]

Here we go again

I think you will have to accept the ride with 19" wheels. You could replace your tires with more comfortable models.

Your tire pressures are also below the car's rated gross axle weights for whatever it's worth. I think 35/38 PSI is the lowest you should go on 88Y XL and 91Y XL tires.

[streetpro]

In my butt feeling e92 335i is less harsh/jerky than was my friends 530i on M suspension and R17 RFT tires... yes, it has lot more noise bot from road/surface and even from engine/exhaust (which is fine when you are seeing red... but on 2+ hours highway drive the fun runs out)... try also change the rear upper dome rubber washer on the shocks (cheap Monroe part), it removes part of the "bumpy" feeling...

[bmw_solid]

Originally Posted by freedomfries

Here we go again

I think you will have to accept the ride with 19" wheels. You could replace your tires with more comfortable models.

Your tire pressures are also below the car's rated gross axle weights for whatever it's worth. I think 35/38 PSI is the lowest you should go on 88Y XL and 91Y XL tires.

19" rims are big but BMW engineers must and should have thought about this in terms of ride quality - not just offer it and put the onus of a bad ride on the customer! If 19" rims were a problem, either they should have offered upgraded bump stops or shocks or simply don't offer that wheel size at all if they couldn't engineer the car to drive as good on 19".

I know I'm running 10% lower pressure but apparently this is widely accepted on various places on the internet and even Tesla's owner Mr Musk once tweeted "to make your Tesla's ride more comfy and quieter, reduce tyre pressures by 10%"

There is also a thread on here about using lower tyre pressures and let's face it...most cars owners are driving with low pressures anyway!

[bmw_solid]

Originally Posted by streetpro

In my butt feeling e92 335i is less harsh/jerky than was my friends 530i on M suspension and R17 RFT tires... yes, it has lot more noise bot from road/surface and even from engine/exhaust (which is fine when you are seeing red... but on 2+ hours highway drive the fun runs out)... try also change the rear upper dome rubber washer on the shocks (cheap Monroe part), it removes part of the "bumpy" feeling...

Which rear upper dome rubber washer are you talking about? The upper mount? I have heard that Monroe do a rubber mount set for the rear shocks but does this improve comfort or handling?

[whyzee125]

I'd install 18" wheels which will make a huge difference. Beyond that you could install the rough road package spring pads or go with the z4 rear bump stops. It will feel a bit sloppier in the rear with lower bump stops but those work fine and will not allow TOO much articulation where you're going to have issues.

As always, try the cheapest option first then go from there.

Swapping out for a shorter OEM bump stop first is likely your best bet, followed by the cheap upper rear mount option peeps have already suggested.

In the end though you'll learn the hard way that the soft stock replacement shocks can't handle the short sidewall of the 19s. Upgrading to B6s would prob be your best bet as that would provide the biggest bang for your buck.

Downgrading wheel size is always an option too, but you'll still be limited by crummy OEM-like shocks if you leave the B4s in there.

tldr; buy once = cry once

[bmw_solid]

Originally Posted by whyzee125

I'd install 18" wheels which will make a huge difference. Beyond that you could install the rough road package spring pads or go with the z4 rear bump stops. It will feel a bit sloppier in the rear with lower bump stops but those work fine and will not allow TOO much articulation where you're going to have issues.

Rough road package spring pads? Please clarify...what does the rough road package consist of besides the spring pad? Will that pad improve the ride noticeably?

Because the Z4 bump stops are shorter, won't this cause damage to the shocks due to more travel?

[bmw_solid]

Originally Posted by FCobra94

As always, try the cheapest option first then go from there.

Swapping out for a shorter OEM bump stop first is likely your best bet, followed by the cheap upper rear mount option peeps have already suggested.

In the end though you'll learn the hard way that the soft stock replacement shocks can't handle the short sidewall of the 19s. Upgrading to B6s would prob be your best bet as that would provide the biggest bang for your buck.

Downgrading wheel size is always an option too, but you'll still be limited by crummy OEM-like shocks if you leave the B4s in there.

tldr; buy once = cry once

I like your idea of buy once = cry once it makes sense!

What does that cheap upper mount actually do? I heard it is made out of rubber hence doesn't compress as much as the foamy OEM ones....won't this mean a more firm ride in the rear?

Read the reviews in the massive 'Monroe' thread. That should help answer any questions.

[bmw_solid]

Originally Posted by FCobra94

Read the reviews in the massive 'Monroe' thread. That should help answer any questions.

I have seen many monroe threads but can't find an answer. The reason being because most of the people either have lowering springs or premium aftermarket shocks. I need to know how the monroe threads will help a 100% stock E92 SE... How can rubber monroe upper mounts be more comfy compared to the foamy OEM mounts? As rubber is more firm, won't that not make the ride more firm and cut out the waft motion?

Also, do the monroe mounts have a spacer in them to allow more shock travel?

[N8N]

Don't E92s all have sport suspension? Or is that only in the USA?

Originally Posted by bmw_solid

I have seen many monroe threads but can't find an answer. The reason being because most of the people either have lowering springs or premium aftermarket shocks. I need to know how the monroe threads will help a 100% stock E92 SE.

Search harder...the massive Monroe thread states that these work with OEM equipment...pretty easy to find the info.

No, that's not how it works. The firmer rubber gets rid of the bounce/slop that you'll find with the stock foam units. There is no extra NVH because the upgraded pieces are rubber; not, polyurethane, etc. so there is no extra "harshness" introduced at all.

Have you ever seen/handled the lower rubber shock mounts in these cars? They're as stiff as a brick. Just the same, the new upper mounts won't change anything in the comfort department because it's not a radical change in materials. They actually allow the dampers to do their job instead of transferring that undamped energy into the chassis.

Also, yes, you gain shock travel as well.

[bmw_solid]

Originally Posted by FCobra94

Search harder...the massive Monroe thread states that these work with OEM equipment...pretty easy to find the info.

No, that's not how it works. The firmer rubber gets rid of the bounce/slop that you'll find with the stock foam units. There is no extra NVH because the upgraded pieces are rubber; not, polyurethane, etc. so there is no extra "harshness" introduced at all.

Have you ever seen/handled the lower rubber shock mounts in these cars? They're as stiff as a brick. Just the same, the new upper mounts won't change anything in the comfort department because it's not a radical change in materials. They actually allow the dampers to do their job instead of transferring that undamped energy into the chassis.

Also, yes, you gain shock travel as well.

I have been looking at this thread: https://www.e90post.com/forums/showthread.php?t=1145344

Most people report a firmer rear but then again most people in that thread are not on OEM-level shocks and springs so can't determine for sure what these rubber mounts will do in terms of comfort.

I understand the theory about the extra bounce and can see that making the ride more stable and allowing the shocks to react to the bumps rather than undamped energy going into the chassis but why would BMW use foam upper mounts as opposed to rubber then? I'm sure it must be for more comfort? I am not too fussed about the bounce/slop but more concerned about how firm the bump feels....

How much shock travel is gained? Are we talking a couple of mm or something more significant like 10mm? Are the monroe mounts smaller in height compared to OEM?

You're overthinking this way too much. Every concern and detail you've requested has been well documented all across this forum already. Good luck in your search.

[The Nightman]

Originally Posted by bmw_solid

19" rims are big but BMW engineers must and should have thought about this in terms of ride quality - not just offer it and put the onus of a bad ride on the customer! If 19" rims were a problem, either they should have offered upgraded bump stops or shocks or simply don't offer that wheel size at all if they couldn't engineer the car to drive as good on 19".

I know I'm running 10% lower pressure but apparently this is widely accepted on various places on the internet and even Tesla's owner Mr Musk once tweeted "to make your Tesla's ride more comfy and quieter, reduce tyre pressures by 10%"

There is also a thread on here about using lower tyre pressures and let's face it...most cars owners are driving with low pressures anyway!

There is no "widely accepted" practice on tire pressures. It would be negligent to knowingly run pressures lower than the rated GAWR IMO.

Which tires do you have? NVH varies greatly between tire models.

[bmw_solid]

Originally Posted by freedomfries

There is no "widely accepted" practice on tire pressures. It would be negligent to knowingly run pressures lower than the rated GAWR IMO.

Which tires do you have? NVH varies greatly between tire models.

I'm running decent budget brand tyres all round (and non run flats all round). Can't really afford crazy money on premium makes!

10% Lower pressures really help with the ride comfort. At the spec pressures, the car feels like its riding on tyres made out of bricks - each and every single bump is felt and not only felt but felt with a lot of firmness - to a point where I start to get a mild back ache!

10% Lower pressures is like switching from M-Sport suspension to almost-SE-level suspension!

And another thing that's been bugging me is are the factory pressures for cold or warm? I.e. should they be filled to those values when the tyres are cold (sitting for more than 4 hours) or when tyres are warm (driving after 20/30 minutes)?

Ultimately, whether using a budget or premium tyre should not majorly affect the way the car rides... Its a german-built machine and should be over-engineered (to some extent) to allow for variations to the car. Okay, I agree that a premium tyre would put less vibrations and tyre roar into the cabin and improve handling but I don't expect premium tyres to change the way the car handles the bumps! It does not justify having thuds etc with budget tyres and a smooth ride with premium tyres. I have never experienced a radical change in comfort on any of the other cars we have owned in our household so don't really expect premium tyres to offer much change in my E92.

I will try and record a video of the thuds for a better understanding.

[The Nightman]

Originally Posted by bmw_solid

Ultimately, whether using a budget or premium tyre should not majorly affect the way the car rides... Its a german-built machine and should be over-engineered (to some extent) to allow for variations to the car. Okay, I agree that a premium tyre would put less vibrations and tyre roar into the cabin and improve handling but I don't expect premium tyres to change the way the car handles the bumps! It does not justify having thuds etc with budget tyres and a smooth ride with premium tyres. I have never experienced a radical change in comfort on any of the other cars we have owned in our household so don't really expect premium tyres to offer much change in my E92.

Tires make a significant difference! Even with my 235/45R17 balloon tires, there was a noticeable improvement in ride comfort when I switched from Michelin AS3 to Pirelli Pzero AS+. Both are "premium" UHP all season tires too.

And tire pressures are set when cold.

[aphael]

Ok heres the thing, you have mismatched shocks and 19inch wheels. The b4 soaks up bumps very well for a stock setup and handles good. The sachs I do not hear too many good things about. I am not sure where you are getting that they are crashy. It is likely you are running 19 inch wheels with rubber band sidewalls which do ride terribly over any bump to be honest. They also add a lot of unsprung weight which has a huge difference in ride quality.

Switch them to all b4s or sachs, check your bushings/mounts/tierods/alignment. If you are having a lot of issues just get some ohlins, may or may not fix your issue. Also your ride height issue seems a bit off. Different shocks can have different ride heights even with the same spring due to internal valving forces. Mismatched shocks can also disrupt the balance of the car. Lowering tire pressure doesn't mean you are converting levels of suspension, it just doesn't work like that.

You've done a lot to your car but what are you comparing to? Do you know what a msport suspension feels like? Different tires have different sidewall designs which also do affect ride. What tires are you running? I have seen chinese tires that ride like absolute trash. You could also consider getting a set of burners to check if that is the issue, they are cheap at around 100-200$

There is a lot of information in this forum already. At this point you have to eliminate certain factors to find the issue.

[bmw_solid]

Originally Posted by freedomfries

Tires make a significant difference! Even with my 235/45R17 balloon tires, there was a noticeable improvement in ride comfort when I switched from Michelin AS3 to Pirelli Pzero AS+. Both are "premium" UHP all season tires too.

And tire pressures are set when cold.

Of course tyres under a premium make will make a difference but I have never personally experienced this. My brother purchased a 2006 C-Class and it came with Continental Conti-Sport tyres which are recommended for that model. A year later we changed the rear one to budget tyres (Road Star) and they actually were more quieter in terms on road noise as I think the Conti-Sports are designed to give more grip. But the comfort of the car remained the same. The only we noticed a difference in comfort is when we replaced the rear coils! If BMW cars are sensitive to tyres then that really sucks in all honesty!

Thanks for confirming re. tyres pressures.