[terrywang]

Need to get some input from OG F87 owners who has flashed back to stock.

Long story short

Put bm3 stage 1 (MultiMap) on the stock care (Oct 2016 build, never updated iSTEP or so).

I didn't quite like the sound with OTS stage 1, I've been busy and don't have time to trial and error - change the OTS map config and test (don't know how I can get close to stock sound), so I decided to flash back to stock for now.

However, flashing back to stock, the car feels different, especially the sound, in SPORT+ the burble and backfire completely disappeared.

I thought the stock tune was the stock map + any configuration on the car but didn't work that way. It wasn't a backup of the stock tune on the car before flashing bm3...


bm3 support told me to re-lock DME, which is supposed to completely remove bm3 and restore the car to stock, it didn't bring back the burble and backfire, tried toggle ASD ON/OFF, and noticed a slight change, only 10% is back, really confused.

The car is definitely not what it use to be before flashing bm3. Sound is different, I mean the sound burble and backfire (pops and bangs when lifting at around 5k rpm was consistently loud but not too loud), cold start was pretty loud and now it's not.

---

Now, to me, it appears that I'll need to make various config changes to the stock tune, to many options, e.g. Exhaust burble type, etc., to match my car's stock config (which is uknow - not backed-up...) to get back to what it use to be? Am I correct?

Does anyone know?

It use to sound like this - Cold start: https://soundcloud.com/terrywan9/f87-cold-start

TIA


TL;DR

SOLUTION: code ASD to ON before flashing bootmod stage 1 or other OTS maps. If you have already flashed with ASD coded OFF, restore ASD using BimmerCode or tools of your choice. Flash again. The roaring exhaust note should be back! This should apply to other tuning tools like MHD Tuning as well.

Basically ASD coding status messed up the sound.

[ThreeStripes]

Didn’t have this experience fwiw. When I went back to stock and re-locked it was back to the stock behavior. I know that’s not helpful to your situation but some anecdotal feedback nonetheless.

[NSXR]

I figured it would be simple to flash back to stock. I think PTF's make it sound like it's a 30 second affair. Interesting.

[ggggbmw]

I used BM3 flash my car back to stock. Previous owner had MHD stage 2 and a catless downpipe on the car when I bought it. Hated that, so bought BM3 and flashed stage 1 OTS. Car ran better but can't say I heard a difference in burbles/pops. Put the original cat back on, and flashed to stock tune, but didn't lock the DME. Again, aside from the drop in sound from having a cat back on, didn't notice any change in sound behavior.

Where I hear a major change is when I put the car in DTC mode. Tons of burbles there.

[terrywang]

There are too many missing pieces from "Stock Tune", lots of moving parts

ASD on/off
Exhaust burble type (OEM, Original, OTS etc.)

Tech support pointed me to flash back to stock tune, re-lock DME and change to Original (type exhaust burble), it didn't work to restore the original sound, damn.

Looks like once you flash, you lose what are supposed to be backed up as stock tune + configuration / calibration.


What bootmod3 tech support offers is asking customer to tweak, trial and test until it sounds close to OG F87 stock tune...

[Ronayke]

Originally Posted by terrywang

There are too many missing pieces from "Stock Tune", lots of moving parts

ASD on/off
Exhaust burble type (OEM, Original, OTS etc.)

Tech support pointed me to flash back to stock tune, re-lock DME and change to Original (type exhaust burble), it didn't work to restore the original sound, damn.

Looks like once you flash, you lose what are supposed to be backed up as stock tune + configuration / calibration.


What bootmod3 tech support offers is asking customer to tweak, trial and test until it sounds close to OG F87 stock tune...

I have the same problem. However, MHD was previously used to tune the car. Now fully back to stock and all the burbles are gone.
I also had some things coded via Bimmercode, also put the original backup, but still, burbles are not present...

Did you find a solution to this?

[terrywang]

Too busy recently, I've been working with bootmod3 tech support on this.

It may be related to coding ASD ON/OFF before flashing bootmod3 (and flash back to stock tune).

I was under the wrong impression that in BimmerLink toggling ASD ON/OFF was coding ASD but it's not (more like a diagnostic function to turn on/off). I need to code it (using BimmerCode backup) to the original state - which should be UNASSIGNED in BimmerCode (standard - non expert UI). And then try again, I haven't got the time to test it out yet but according to Halim that may be the cause...

[Ronayke]

Originally Posted by terrywang

Too busy recently, I've been working with bootmod3 tech support on this.

It may be related to coding ASD ON/OFF before flashing bootmod3 (and flash back to stock tune).

I was under the wrong impression that in BimmerLink toggling ASD ON/OFF was coding ASD but it's not (more like a diagnostic function to turn on/off). I need to code it (using BimmerCode backup) to the original state - which should be UNASSIGNED in BimmerCode (standard - non expert UI). And then try again, I haven't got the time to test it out yet but according to Halim that may be the cause...

I did code back ASD to "UNASSIGNED" with Bimmercode, but to no avail... It still doesn't burble.

What I found out, is that you can actually see when the burbles are shutdown.
Open Bimmerlink > Dashboard > Add 'Overrun shutdown condition'. Then you see a 0 when the car is idling, but when it should burble when you let off the throttle, it shows a 1 (so it shuts down the overrun = burbles)...

Super weird issue. Everything is coded back to stock on my car (hardware also), but it refuses to burble...

[terrywang]

Originally Posted by Ronayke

I did code back ASD to "UNASSIGNED" with Bimmercode, but to no avail... It still doesn't burble.

What I found out, is that you can actually see when the burbles are shutdown.
Open Bimmerlink > Dashboard > Add 'Overrun shutdown condition'. Then you see a 0 when the car is idling, but when it should burble when you let off the throttle, it shows a 1 (so it shuts down the overrun = burbles)...

Super weird issue. Everything is coded back to stock on my car (hardware also), but it refuses to burble...

Uh-oh, I haven't got time to test it yet. I am with hope that restore from a backup - code it back may work. But I am skeptical.

Have you eventually solve the problem? I was told ISTA+ flash and recalibration may be the last resort - really? I bit disappointed that flashing back to stock tune doesn't work "AS expected".

Do we have proper (adjustable burble and backfire if flashed to bm3 stage 1 or stage 2)?

[terrywang]

Originally Posted by Ronayke

I did code back ASD to "UNASSIGNED" with Bimmercode, but to no avail... It still doesn't burble.

What I found out, is that you can actually see when the burbles are shutdown.
Open Bimmerlink > Dashboard > Add 'Overrun shutdown condition'. Then you see a 0 when the car is idling, but when it should burble when you let off the throttle, it shows a 1 (so it shuts down the overrun = burbles)...

Super weird issue. Everything is coded back to stock on my car (hardware also), but it refuses to burble...

I did "trial and error" over the weekend and it is exactly as you said.

It appears that when it should produce burbles / backfire, the behaviour is "SHUTDOWN" - "overrun shutdown condition" vaue set to 1.






Explanation - see blow, it makes sense. Just don't know what to change to revert back. Need to dig deeper, I am working with bm3 support on this still..

I'll flash to bm3 stage 1 and flash back to stock tune (this time I won't change anything on the stock tune - currently set exhaust burble to original as a part of tech support troubleshooting) and see how it goes.

I feel we are pretty close to the cause, fingers crossed.

----------

ChatGPT provided the following info I think it makes sense but as a bootmod3 user, I would expect the car would simply return to stock including overrun behaviour after flashing back to stock tune and re-lock DME. But it's NOT.

When you flash BM3 Stage 1 the ECU “learns” new fuel‐and‐timing strategies—and sometimes one of the side effects is that a parameter controlling overrun shutdown is modified. In factory‐calibrated software, the overrun shutdown (or “fuel cut‐off on deceleration”) is tuned so that while fuel is cut to save fuel and reduce emissions, there’s still enough residual fuel (or timing variation) to produce the characteristic burble/backfire sounds when you let off the throttle or during downshifts.

In many BM3 tunes, however, that overrun shutdown condition is set too aggressively (or “left on”), so during coasting or downshift events the fuel is cut entirely, resulting in muted or absent burbles and pops.

To restore the original behavior you’ll need to adjust the parameter that controls the overrun shutdown threshold in your fuel map. In BM3’s Advanced Map Editor (or via Bimmerlink if you’re reading and editing live data) there is a setting—often labeled “Overrun Shutdown Condition” or “Deceleration Fuel Cut” threshold—that tells the ECU when to completely cut off fuel injection during overrun.

The solution is to revert that setting to the OEM calibration value. In practice, this means either:

• Using BM3’s built‐in “Stock Tune” parameters (or a custom version that mimics OEM behavior) so that the overrun shutdown condition is relaxed (or “disabled” in the sense that fuel isn’t abruptly cut off) during deceleration; or
• Using a tool like Bimmerlink (or even dealer-level software such as ISTA+) to read and then adjust the fuel/injection tables so that the deceleration cut‐off is set to the factory value—allowing a little bit of fuel (and the proper ignition timing) during overrun, which in turn produces the burble, autoblip, and backfire sounds you expect.

In short, check your BM3 (or Bimmerlink) settings for the “Overrun Shutdown Condition” parameter. It is likely set to “ON” or to a threshold that’s too low, meaning the ECU cuts fuel too early. Reset that parameter to the OEM default (or the value from a known-good stock calibration) so that fuel remains present during overrun events. That should restore the natural burble/backfire behavior that you remember from your original stock tune.

This parameter is sometimes hidden in the advanced fuel mapping tables in BM3 or Bimmerlink, so you may need to consult the detailed documentation or ask your tuner for the OEM calibration values if you’re not sure what the factory setting should be.

By ensuring that the overrun shutdown condition is adjusted (i.e. not set to aggressively cut fuel), your car should then produce the characteristic crackles and pops during deceleration and downshift events as originally intended.

**Citations:**
citeturn4search0 (Bimmerpost thread discussing overrun shutdown conditions)
citeturn3search18 (bootmod3 FAQ on protuningfreaks.com)

[Ronayke]

I got into contact with a professional coder and he put all the settings of ASD back to original as it would come from the factory (in case Bimmercode wouldn't do a good job with the backup).

Unfortunately, this didn't bring back the exhaust burbles...

Therefore, I think it is a problem with the software on the DME...

[John wk]

Originally Posted by terrywang

Need to get some input from OG F87 owners who has flashed back to stock.


Long story short

Put bm3 stage 1 (MultiMap) on the stock care (Oct 2016 build, never updated iSTEP or so).

I didn't quite like the sound with OTS stage 1, I've been busy and don't have time to trial and error - change the OTS map config and test (don't know how I can get close to stock sound), so I decided to flash back to stock for now.

However, flashing back to stock, the car feels different, especially the sound, in SPORT+ the burble and backfire completely disappeared.

I thought the stock tune was the stock map + any configuration on the car but didn't work that way. It wasn't a backup of the stock tune on the car before flashing bm3...


bm3 support told me to re-lock DME, which is supposed to completely remove bm3 and restore the car to stock, it didn't bring back the burble and backfire, tried toggle ASD ON/OFF, and noticed a slight change, only 10% is back, really confused.

The car is definitely not what it use to be before flashing bm3. Sound is different, I mean the sound burble and backfire (pops and bangs when lifting at around 5k rpm was consistently loud but not too loud), cold start was pretty loud and now it's not.

---

Now, to me, it appears that I'll need to make various config changes to the stock tune, to many options, e.g. Exhaust burble type, etc., to match my car's stock config (which is uknow - not backed-up...) to get back to what it use to be? Am I correct?

Does anyone know?

It use to sound like this - Cold start: https://soundcloud.com/terrywan9/f87-cold-start

TIA

I have something similar. I have MHD stage 2, which is equivalent to stage 1 of bm3. I have the multimap and in map 1 I have the OEM sound, which is the one I have been using lately, without bubbling... in traction mode, which is where it should backfire, it doesn't make any noise, so if it wants explosions it has to be in map 2, which bubbles softly, map 3 medium and map 4 loud.

[terrywang]

Originally Posted by John wk

I have something similar. I have MHD stage 2, which is equivalent to stage 1 of bm3. I have the multimap and in map 1 I have the OEM sound, which is the one I have been using lately, without bubbling... in traction mode, which is where it should backfire, it doesn't make any noise, so if it wants explosions it has to be in map 2, which bubbles softly, map 3 medium and map 4 loud.

Thanks for sharing. Interesting, I suspect that the MultiMap (relatively new?) option may have something todo with this.

[terrywang]

Originally Posted by Ronayke

I got into contact with a professional coder and he put all the settings of ASD back to original as it would come from the factory (in case Bimmercode wouldn't do a good job with the backup).

Unfortunately, this didn't bring back the exhaust burbles...

Therefore, I think it is a problem with the software on the DME...

I coded ASD back to its original state when the car was connected to BimmerCode for the first time, same outcome, it didn't bring back the burble.

I'll flash to bm3 stage 1 - MultiMap again and try different maps - I'll use Map 3 - which is the Stage 1 Octane 93, see how it works under this map.


So if you use MHD tune maps, does the car produce burbles?

[John wk]

I imagine that mhd and bm3 are very similar. Mhd has 4 map options, in each map you can set octane 91-93, power from 50% to 100% of stage 1 and then in each map different burbels, soft, medium and strong and different duration of seconds of bubbling.
the power from 50% to 100% I don't think it will vary much, since if we start with 370hp, a stage 1 will give it about 40hp as a maximum... we are talking about 50% being 20hp... in the multimap from 390hp to 410hp I don't think it will be very noticeable... then you can configure how the accelerator, the http, the start-up roar deliver the power, eliminate the start/stop, etc.

[terrywang]

I spent some time this weekend on this weird problem. I believe I am getting closer to the truth / cause of the problem.

I coded ASD OFF using BimmerCode; somehow I thought BimmerLink ASD toggled OFF was the same (it's NOT). Without realizing the difference, I unlocked DME and flashed bootmod3 stage 1 (MultiMap), the car sounds really weird, of course, ASD was coded OFF.

Not happy with the sound, I flashed back, losing the burbles (backfire) completely.

After working with bootmod3 support and intensive research + troubleshooting, eventually I narrowed it down to ASD coded ON vs. OFF.

This weekend I flashed to bm3 stage 1 again. It sounds close to the original (stock tune) good!

I used BimmerCode dashboard - monitoring "overrun shutdown conditions" - when it burbled, backfired, value was 0, value did NOT changed to 1 until the burbles stopped.

Next step, I'll flash back to stock tune (may be 1 month later, no point to use stock now that I've fixed stage 1 sound).