[Antmit]

Hi

I’ve looked on here for similar posts but none seem to be here.

I test drove an m850i in April last year for a couple of days, and I absolutely loved it, especially the gurgle / burble when coming down through the gears.

Fast forward a year and I got one of my own. Although I absolutely love it, and it makes my 6 convertible before it feel like a Mini, there’s one thing that seems to be missing: that burble gurgle. It’s the same engine, with almost the same spec and even a bit higher.

Was this gurgle the result of an extra that I wasn’t aware of, as try as I might I can’t hear it even in Sport Plus. Is it something that comes as the engine ages (I’ve only managed to do 2k since mid May)? Assistance would be appreciated.

[Ozzie8]

In sport plus and engine at least warm, works every time.

[Dex85]

It might have something to do with you being in the UK (EU regulations) and Ozzie in Australia..... :/

[bloozemanAZ]

Originally Posted by Dex85

It might have something to do with you being in the UK (EU regulations) and Ozzie in Australia..... :/

BMW is definitely limiting the exhaust sound in the UK and some of that has unfortunately made its way here to the US. Mostly on my 2020 M850i it has impacted the cold start but I've also noticed that Sport does not burble like it used to. I had always driven the car in Sport Individual with the engine/transmission set to Sport and the suspension to comfort (back when I commuted pre-COVID19 some of the streets were too rough for Sport).

Thankfully Sport Plus still offers all the burbles, etc. but the transmission is too aggressive for normal street driving to the grocery store, etc. However, I found the silver bullet, i.e., I now have the engine set to Sport Plus within my Sport Individual configuration and I'm once again a happy camper.

[Ozzie8]

Yes we sort of need something in between sport and sport plus or a burbles button on the steering wheel.

[Antmit]

I did wonder if it might be due to noise legislation, but the car I test drove was a 68 plate and mine is a 20, so there can't have been so much of a change in that time?

Noted re Sport Plus + Individual config. I'll give that a try the next time I'm out in it.

In between ordering and delivery (which got caught by the lockdown) I used to watch a lot of YT videos (mainly the guy on CarWow) and one was of a couple of Cornish brothers who took it to a CostCo car park and scared people to death. I was looking forward to doing that, just in case the .1% of people who weren't looking at it just hadn't seen it.

This car gets sooooo many looks!

[msm2000uk]

Originally Posted by Antmit

I did wonder if it might be due to noise legislation, but the car I test drove was a 68 plate and mine is a 20, so there can't have been so much of a change in that time?

Noted re Sport Plus + Individual config. I'll give that a try the next time I'm out in it I'll give that combo a try.

In between ordering and delivery (which got caught by the lockdown) I used to watch a lot of YT videos (mainly the guy on CarWow) and one was of a couple of Cornish brothers who took it to a CostCo car park and scared people to death. I was looking forward to doing that, just in case the .1% of people who weren't looking at it just hadn't seen it.

This car gets sooooo many looks!

Hello from another UK owner - there are a few of us on here.

Mine is also a 68, and the exhaust noise changed when I had the car serviced and the iDrive software updated to 03.2020.

I've since had the car remapped by DMS Automotive, and they also did an exhaust software swap for me, so the burbles are back thankfully!

My 191mph, 729bhp monster now has the sound to match the performance!

M

[Antmit]

Originally Posted by msm2000uk

Hello from another UK owner - there are a few of us on here.

Mine is also a 68, and the exhaust noise changed when I had the car serviced and the iDrive software updated to 03.2020.

I've since had the car remapped by DMS Automotive, and they also did an exhaust software swap for me, so the burbles are back thankfully!

My 191mph, 729bhp monster now has the sound to match the performance!

M

Hi indeed.

I’ve not had my first service yet, but I did receive a downloaded OS update. I don’t know the version of the top of my head but will look and check the date.

I’m hopeful that it’s something that either kicks in through natural wear, or is something that is applied intentionally after that first service. It was such a great thing to hear, and it’s bad enough that BMW have had to reduce so much of its external noise. When it revs though, it sounds sweet.

Curious regarding your remapping, does that not void warranty? I presume from your profile that you have an 850 too? 791 bhp really?

[Dex85]

Originally Posted by msm2000uk

Hello from another UK owner - there are a few of us on here.

Mine is also a 68, and the exhaust noise changed when I had the car serviced and the iDrive software updated to 03.2020.

I've since had the car remapped by DMS Automotive, and they also did an exhaust software swap for me, so the burbles are back thankfully!

My 191mph, 729bhp monster now has the sound to match the performance!

M

So you're saying we need to do a remap of the ECU to get the exhaust noise back?

[msm2000uk]

Originally Posted by Antmit

Hi indeed.

I’ve not had my first service yet, but I did receive a downloaded OS update. I don’t know the version of the top of my head but will look and check the date.

I’m hopeful that it’s something that either kicks in through natural wear, or is something that is applied intentionally after that first service. It was such a great thing to hear, and it’s bad enough that BMW have had to reduce so much of its external noise. When it revs though, it sounds sweet.

Curious regarding your remapping, does that not void warranty? I presume from your profile that you have an 850 too? 791 bhp really?

The noise wont just magically return unfortunately, but software can bring it back. Bear in mind also, that the sound you hear in the car is not necessarily what is heard outside (due to the fake noise thing BMW use).

The remap would invalidate the warranty if BMW find it, but I've mapped around 150 cars (BMW, MB, AMG, Audi etc) and never had an issue.

And yes, 729bhp from my M850i - purely from software.

M

[msm2000uk]

Originally Posted by Dex85

So you're saying we need to do a remap of the ECU to get the exhaust noise back?

You don't need to remap the ECU to add the burbles back, but you do need to re-code the exhaust ECU - not a difficult process if you have the necessarily tools.

M

[bloozemanAZ]

Originally Posted by Antmit

In between ordering and delivery (which got caught by the lockdown) I used to watch a lot of YT videos (mainly the guy on CarWow) and one was of a couple of Cornish brothers who took it to a CostCo car park and scared people to death. I was looking forward to doing that, just in case the .1% of people who weren't looking at it just hadn't seen it.

This car gets sooooo many looks!

I've done the car park aspect with my M850i as well as strategic burble eruption when passing by people walking on the sidewalks as I drive by. If they weren't looking in the first place they definitely gawked after the burbles.

Welcome to the rare 8-series which generates nothing but looks. Here in the Phoenix metro area with nearly 5M people there have been roughly only 100 8-series sold so the vast majority of people have never seen one before. I get comments all the time in car parks, etc. but actually had someone follow me on the freeway to my destination so they could see the car up close.

By the way for my edification what is a plate 68 vs 20? That is not a construct I'm familiar with vs the UK vernacular for car park which translates to parking lot here in the US.

[msm2000uk]

Originally Posted by bloozemanAZ

I've done the car park aspect with my M850i as well as strategic burble eruption when passing by people walking on the sidewalks as I drive by. If they weren't looking in the first place they definitely gawked after the burbles.

Welcome to the rare 8-series which generates nothing but looks. Here in the Phoenix metro area with nearly 5M people there have been roughly only 100 8-series sold so the vast majority of people have never seen one before. I get comments all the time in car parks, etc. but actually had someone follow me on the freeway to my destination so they could see the car up close.

By the way for my edification what is a plate 68 vs 20? That is not a construct I'm familiar with vs the UK vernacular for car park which translates to parking lot here in the US.

The 68 vs 20 is a reference to the year the vehicle was registered, based on the numerical value on our standard numberplates:

18 = March 2018
68 = September 2018
19= March 2019
69 = September 2019
20= March 2020
70 = September 2020 etc

M

[limeypride]

Originally Posted by msm2000uk

The noise wont just magically return unfortunately, but software can bring it back. Bear in mind also, that the sound you hear in the car is not necessarily what is heard outside (due to the fake noise thing BMW use).

The remap would invalidate the warranty if BMW find it, but I've mapped around 150 cars (BMW, MB, AMG, Audi etc) and never had an issue.

And yes, 729bhp from my M850i - purely from software.

M

Did you record any objective data during your runway passes? 1/4 mile, 60-130, a 60mph dig, etc.?

PS: what dyno was used to determine your numbers? All wheel, rear wheel only?

[Dex85]

Originally Posted by msm2000uk

You don't need to remap the ECU to add the burbles back, but you do need to re-code the exhaust ECU - not a difficult process if you have the necessarily tools.

M

Recode? So it's something that's "coded out" ?

[msm2000uk]

Originally Posted by limeypride

Did you record any objective data during your runway passes? 1/4 mile, 60-130, a 60mph dig, etc.?

PS: what dyno was used to determine your numbers? All wheel, rear wheel only?

0-60mph 3.2s
0-100mph 7.3s
50-70mph 1.1s
1/4 mile 10.3s

All according to the Racelogic device in my car, using an external GPS antenna.

In terms of the dyno, I'd have to ask.

M

[limeypride]

Originally Posted by msm2000uk

0-60mph 3.2s
0-100mph 7.3s
50-70mph 1.1s
1/4 mile 10.3s

All according to the Racelogic device in my car, using an external GPS antenna.

In terms of the dyno, I'd have to ask.

M

Great numbers!

[Antmit]

I'm still keen to know if this somehow invalidates any warranty though? I was toying with the idea of doing this for one of my previous cars (2008 635d and 2014 640i) but was always put off by the prospect of potentially causing myself problems down the line. I went as far as buying the interface cable but didn't pluck up the courage when it was IN warranty, and had moved on past the idea by the time they had come OUT of warranty.

[msm2000uk]

Originally Posted by Antmit

I'm still keen to know if this somehow invalidates any warranty though? I was toying with the idea of doing this for one of my previous cars (2008 635d and 2014 640i) but was always put off by the prospect of potentially causing myself problems down the line. I went as far as buying the interface cable but didn't pluck up the courage when it was IN warranty, and had moved on past the idea by the time they had come OUT of warranty.

Does it invalidate your warranty? Yes. A remap will absolutely invalidate your warranty but that is on the basis BMW can find it - which they wont.

BMW will be able to see the ECU has been touched and they'll ask you questions - but you can simply either plead ignorance, or say you did an over the air update which may have affected it.

A good remapping company will bury the code very well. I use one such company, and they have remapped circa 150 cars from friends/family of mine. Not a single one has ever had an issue with the warranty.

My car was remapped in January, and has had 2 software updates and a service since then. All were done by BMW, and not a single time have they said anything.

You would have to be epically unfortunate to be caught out because BMW usually just wipe the ECU and update the software (without looking to see if the ECU has been touched previously).

Again, a good remap company will put the map back on (for free).

M

[Wolfman64]

Originally Posted by msm2000uk

Does it invalidate your warranty? Yes. A remap will absolutely invalidate your warranty but that is on the basis BMW can find it - which they wont.

BMW will be able to see the ECU has been touched and they'll ask you questions - but you can simply either plead ignorance, or say you did an over the air update which may have affected it.

A good remapping company will bury the code very well. I use one such company, and they have remapped circa 150 cars from friends/family of mine. Not a single one has ever had an issue with the warranty.

My car was remapped in January, and has had 2 software updates and a service since then. All were done by BMW, and not a single time have they said anything.

You would have to be epically unfortunate to be caught out because BMW usually just wipe the ECU and update the software (without looking to see if the ECU has been touched previously).

Again, a good remap company will put the map back on (for free).

M

It's a great power increase on your car. Nice! Best bang for the buck as long as anyone is aware of the potential risk to the warranty, however small.

It's a myth that BMW can't find traces of a tune if they have to (actual damage). They will and have...
If some tech sees mods in the flesh and doesn't like you, your car can be black listed and any service or warranty work will require prior approval which will be a PITA.

[limeypride]

Originally Posted by msm2000uk

Does it invalidate your warranty? Yes. A remap will absolutely invalidate your warranty but that is on the basis BMW can find it - which they wont.

C'mon, dude--that last part is codswallup. If BMW want to know, they'll know. Read on before you get mad at me; perhaps I'll convince you... perhaps not.

// tl;dr-->gobs of technical drivel follows

BMW will be able to see the ECU has been touched and they'll ask you questions - but you can simply either plead ignorance, or say you did an over the air update which may have affected it.

I don't agree here but this is my subjective opinion--subjective because *I don't personally* know what BMW does as a a matter of course for every single warranty repair. However, I do know what's technically plausible since that's what I do for a living... albeit for a different operating system.

So that said and to your point on pleading ignorance with BMW: this assumes they accept the burden of proof... because it's a moot point if they don't. For me, I don't think that BMW will accept the burden of proof when they 1) can't explain a given failure and 2) can attribute it to aftermarket mods--they'll say no and push the burden back on the customer. That's purely my opinion, though.

A good remapping company will bury the code very well.

You can't *bury* code--this doesn't mean anything in the realm of technical reality. As an industry, we no longer run arbitrary code--especially in a boot chain--rather, we sign each binary (binary is geek-speak for an executable file) as a unit which results in a cryptographically-unique signature. That signature is then used to identify and prove legitimacy in a larger chain of trust. Each binary within the chain is enlightened with the cryptographic signature of the next binary in the chain. A binary will only hand-off to the next binary once its signature has been validated and the binary deemed trustworthy. Change one BIT of any binary and the signature is radically changed... as a result, the boot path fails (well, it fails if that's the desired outcome as it is with general-purpose operating systems; if it's not a general-purpose OS--as is likely the case with a car's OS--they'll probably log it rather than fail). Intercepting and injecting binaries into this chain for malicious purposes is, to date, thought to be computationally infeasible hence the recent popularity of so-called side channel attacks.

To explain how BMW can preserve and know what we might have done over time, you'd need to understand what a TPM is; what a PCR is; how PCRs are extended; what a chain of trust is; what PKI is; how asymmetric crypto works; how code is signed, etc. Once someone understands these core crypto technologies, they'll understand why claims of "they can't tell" or "they don't know" are unlikely to say the last (I say unlikely because I don't know how much of this BMW has implemented).

I use one such company, and they have remapped circa 150 cars from friends/family of mine. Not a single one has ever had an issue with the warranty. My car was remapped in January, and has had 2 software updates and a service since then. All were done by BMW, and not a single time have they said anything.

2 times is wildly statistically insignificant; even 152 times is. I also suspect most warranty claims aren't downstream of the drivetrain--rather, they're power seat issues or AC issues.

You would have to be epically unfortunate to be caught out because BMW usually just wipe the ECU and update the software (without looking to see if the ECU has been touched previously).

Wrt/ "BMW usually just wipe the ECU": that's not remotely representative of my firsthand experience with any of my Ms nor does it make rational sense to me. It's all software these days--human beings attach the cables and magic happens. I think it's fair to say there's a lot of stuff going on once those cables are attached. However, that's opinion, not fact.

Again, a good remap company will put the map back on (for free).

M

Measuring flash counters into a PCR (or persisting/leveraging it in a variety of other ways) and measurements from the aforementioned boot chains themselves render flashing back to stock utterly futile. If BMW *want* to know, they'll know... and there's nothing (so far) that any of us can do about it.

PS: I'm told (unsubstantiated) that they now use yaw sensors and accelerometers combined to record performance metrics independent of the ECU--that covers ECU tunes, piggys, jetpacks attached to the car's arse and go faster stripes.

[limeypride]

Originally Posted by Wolfman64

It's a great power increase on your car. Nice! Best bang for the buck as long as anyone is aware of the potential risk to the warranty, however small.

It's a myth that BMW can't find traces of a tune if they have to (actual damage). They will and have...
If some tech sees mods in the flesh and doesn't like you, your car can be black listed and any service or warranty work will require prior approval which will be a PITA.

Great point--the *human* part of the equation.