BMW M2 Anti-Lag braaap sound after lifting the throttle

meppadua · 03-14-2021, 06:51 PM

I got a notification saying BM3 needs an update. After updating the app, i jump on to their website to see what the new features are. They say Anti Lag, Map switching, and a couple of other things, but all this stuff says it ONLY works on S55 engines... BUMMER

Thomas590 · 03-15-2021, 02:21 AM

Then you probably have to wait for N55 support. Those features you mentioned will not add the thing which we are here talking about

meppadua · 03-23-2021, 12:38 PM

Quote:

Originally Posted by Thomas590

Then you probably have to wait for N55 support. Those features you mentioned will not add the thing which we are here talking about

Looks like M2 i go!

Thomas590 · 03-24-2021, 04:25 AM

Quote:

Originally Posted by meppadua

Looks like M2 i go!

Some people know how to save money and some people don't.

meppadua · 06-04-2021, 10:50 PM

BM3 did an update for N55 platform, the Anti Lag is different from what ive seen on videos compared to tha M2 DME. Still on tha hunt for that Braap sensation when you lift off tha throttle..

Thomas590 · 06-21-2021, 03:25 PM

Quote:

Originally Posted by meppadua

BM3 did an update for N55 platform, the Anti Lag is different from what ive seen on videos compared to tha M2 DME. Still on tha hunt for that Braap sensation when you lift off tha throttle..

I might be wrong but nobody yet make it as ready to resell product.

Thomas590 · 07-10-2021, 11:54 AM

Quote:

Originally Posted by LA1Z24

On the new RK Tunes video, he has his new M3 on the dyno, and on lift, it makes a noticeably different noise than the standard burble.

At the 4 minute mark

Quote:

Originally Posted by Phantom10R

that's the Rev limiter

Yea, that's a common sense.. That's not even nearly close to the sound we are here talking about. I'm surprised that there is lack of interest to get this done. I would probably do it by myself but I don't need a third car atm.

To be clear, we are looking for that sounds when he lifts off the throttle

Thomas590 · 11-22-2021, 09:48 AM

Hey, anyone yet figure it out?

rtl32 · 11-28-2021, 09:46 PM

I've noticed this is common on all the actual M cars - I think it has something to do with the DCT's relationship with the ECU (causing ignition to retard timing to slow the RPM faster to shift faster) and thus creates a anti lag effect similar to that of the new flash tune antilags.

If I were to guess- they both retard timing heavily to create boost, one (flashed M235i) does it to limit RPM climb during boost build up and the other (M2 that makes this sound) does it to actively lower RPM between shifts but with the same mechanism (deep negative timing - essentially running gas through the cylinder and out while engine braking hard off the compression phase). N55 M2 w/ 6MT models probably share the same ECU as the DCT M2 and and have a similar ignition retard function on shifts because it has auto rev match, which does the same quick reduction of RPM mid shift.

My 2 cents. Programming this in would likely go hand in hand with auto rev match features. It also may not be possible to tune in this condition to our ECUS. Could someone from protuning freaks mhd or other tuning company with an understanding of both platforms pitch in?

Thomas590 · 12-01-2021, 02:59 PM

Quote:

Originally Posted by rtl32

I've noticed this is common on all the actual M cars - I think it has something to do with the DCT's relationship with the ECU (causing ignition to retard timing to slow the RPM faster to shift faster) and thus creates a anti lag effect similar to that of the new flash tune antilags.

Check the M2 or M3/M4 without DCT but with manual transmission.
It still does exact same sound, so it's proven that it doesn't matter if it's manual or DCT.

Quote:

Originally Posted by rtl32

My 2 cents. Programming this in would likely go hand in hand with auto rev match features. It also may not be possible to tune in this condition to our ECUS. Could someone from protuning freaks mhd or other tuning company with an understanding of both platforms pitch in?

Some people say that they are working on it, but I don't think it's true.

Quote:

Originally Posted by lucasborka

Mhd is currently working on this for our n55 Cars 🤙🏻

No news since then.

Quote:

Originally Posted by LA1Z24

They've been 'working on it' for over a year now.

Yea I agree, I really would like to have it. N55 sounds so good with it.

Thomas590 · 01-16-2022, 07:51 AM

Quote:

Originally Posted by Phantom10R

Cary Jordan has it as one of his options when custom tuning. it's an additional charge over the tune cost. it's called aggressive overrun. nobody in their right mind is paying additional for it.

Do you have any quote how much for it?

Quote:

Originally Posted by redbullfan

They are coming out with it. Its in the works.

Any source to confirm this?

Seems like 2022 could be a nice year

dalderks · 02-02-2022, 11:08 AM

MHD released the update yesterday! (For those that don't monitor the F30 forum)
https://www.instagram.com/tv/CZcfbzC...dium=copy_link

MLJR235 · 02-02-2022, 03:26 PM

Quote:

Originally Posted by dalderks

MHD released the update yesterday! (For those that don't monitor the F30 forum)
https://www.instagram.com/tv/CZcfbzC...dium=copy_link

lol you beat me to it . Was gonna post it up.. Gotta try it out later and see how good it sounds.

rtl32 · 02-02-2022, 07:19 PM

Quote:

Originally Posted by dalderks

MHD released the update yesterday! (For those that don't monitor the F30 forum)
https://www.instagram.com/tv/CZcfbzC...dium=copy_link

proTUNING Freaks

Your turn!

dalderks · 02-02-2022, 08:02 PM

Quote:

Originally Posted by MLJR235

lol you beat me to it . Was gonna post it up.. Gotta try it out later and see how good it sounds.

Haha I just got it flashed, but probably won't get to really try it until this weekend. Hoping for some dry weather...

rtl32 · 02-04-2022, 12:53 AM

I'm quoting Cary Jordan from a thread a while back:

https://f80.bimmerpost.com/forums/sh....php?t=1208681
(Post 14)

"I haven't been able to confirm my theory, but I think the DME is re-using charge pipe boost on throttle lift for anti-lag purposes by allowing the throttle plate to stay open on lift-off allowing the engine to ingest the excess boost, which pushes the excess boost through to the turbine section, helping to keep the turbos spooled and the EWGs are helping to facilitate this as well by either bypassing the turbine wheel or allowing the pressure to flow through the turbine wheel depending on what conditions merit. The throttle plate remaining open on throttle lift-off is confirmed by me through datalogs. This would also help explain the brap or "farts" that you hear during a lift-off event with significant boost pressures. I suspect that there might be some valve overlap trickery going on during these events as well. This would also help explain the "swoosh" sound we hear in the intakes from the sound of the excess boost slipping back past the throttle plate.

So, by doing this, BMW has achieved two things. A form of anti-lag as well as keeping the excess boost pressure from backing back up in the turbos without the use of a diverter valve. Brilliant, actually."

Sounds like because the S55 does not have a charge side pressure discharge (BOV or recirculating DV like we have on the N55), it creates situations where the pressure flows out of the engine quickly rather than in a manner that would produce useable torque by retarding the timing heavily while keeping the throttle plate open temporarily following a throttle lift off.

AKA, blow the mixture through with such delayed combustion that as the exhaust valve opens it blows up and out of the cylinder as the piston travels up in the exhaust phase instead of during it's normal combustion/power phase. No power, crazy sound, turbulent gasses still working on the turbine.

As CJ said, this is similar to a traditional rally type antilag that works by moving the combustion of the air/fuel mixture from the cylinder to the actual turbocharger housing pre turbine, to maintain the wheel speed and hence immediate booster throttle response as the driver gets back on the throttle.

Another post in this thread much earlier on suggested that this braap sound might happen because of a change in the exhaust valve matrix, which even in a vanos/timing chain controlled setup is not possible because it is SO far out of the normal operation (would require rotations not degrees of the camshaft to complete). I think that logic was on the right path but instead of physically allowing the normal combustion process to escape with altered exhaust valves, I think it just alters the timing of the combustion instead.

HERE is my proposal:

MHD users with this at their disposal! Log a few vigorous runs with (both settings) and then without this feature enabled with throttle angle, MAP, (both intake manifold and charge pipe) and any fuel injector duty cycle channels open. Let's see if there is any difference in both the throttle plate behavior and the boost trends in the logs of each mode. If we see boost being held longer with less throttle snapback on off throttle, we might be able to suspect this mode is actually just disabling the DV control and forcing everything into the engine with slight updates to make that situation safer for the longevity of the turbos.

Thomas590 · 02-04-2022, 07:26 AM

Quote:

Originally Posted by jyerelek

Some good news finally!

But if somebody complains about the sound not being aggressive like on the other videos, keep in mind that it's on stock exhaust system + high flow cat.

I want to hear it with catless + turbo back exhaust system.

Thomas590 · 02-07-2022, 04:09 AM

Anyone yet tried with catless?

Thomas590 · 02-10-2022, 06:59 AM

Quote:

Originally Posted by hellyesmorgan

YAYYYYYYYY can't wait to flash this when I get home. I'm catless, resonator-delete with OEM muffler. I'll see if I can record some video soon Thomas590

What setup you are running?

Quote:

Originally Posted by fortythirtyfive

I've found 5-6th gear pulls causes enough boost to create it

Hard to hear on the video as my phone was in the cup holder but I'm starting to hear it now (short brap setting) I'm catless with the exhaust valve open to bypass the resonator and muffler.

Any chance you can try the long brap setting + record it outside please.

Since you are catless + bypassing resonator and muffler it should sound similar to what we could see in the first video.

whoismorggan · 02-10-2022, 09:43 AM

Quote:

Originally Posted by Thomas590

What setup you are running?

Exhaust setup? It's posted above

sl0w_N55 · 02-18-2022, 03:24 AM

Little late but MHD just added the Braap feature for all N55's. You can choose between short and long(M2 vs M2C sound).

Thomas590 · 02-22-2022, 12:04 PM

Quote:

Originally Posted by sl0w_N55

Little late but MHD just added the Braap feature for all N55's. You can choose between short and long(M2 vs M2C sound).

Yup, looking forward to see more catless trubo back exhaust clips

That's what I found so far:

https://www.youtube.com/shorts/q0YJ7W9SOe4

https://www.youtube.com/shorts/xddbNMbjQ3E

03-14-2021, 06:51 PM	#89
meppadua Private 17 Rep 72 Posts Drives: F22 Join Date: Jan 2017 Location: San Antonio/San Jose iTrader: (0)	I got a notification saying BM3 needs an update. After updating the app, i jump on to their website to see what the new features are. They say Anti Lag, Map switching, and a couple of other things, but all this stuff says it ONLY works on S55 engines... BUMMER
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03-15-2021, 02:21 AM	#90
Thomas590 Private 27 Rep 86 Posts Drives: A3 2.0T Join Date: Sep 2019 Location: EU iTrader: (0)	Then you probably have to wait for N55 support. Those features you mentioned will not add the thing which we are here talking about
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06-04-2021, 10:50 PM	#93
meppadua Private 17 Rep 72 Posts Drives: F22 Join Date: Jan 2017 Location: San Antonio/San Jose iTrader: (0)	BM3 did an update for N55 platform, the Anti Lag is different from what ive seen on videos compared to tha M2 DME. Still on tha hunt for that Braap sensation when you lift off tha throttle..
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11-22-2021, 09:48 AM	#96
Thomas590 Private 27 Rep 86 Posts Drives: A3 2.0T Join Date: Sep 2019 Location: EU iTrader: (0)	Hey, anyone yet figure it out?
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11-28-2021, 09:46 PM	#97
rtl32 Private First Class 73 Rep 196 Posts Drives: M235i 6MT Join Date: Nov 2020 Location: NJ iTrader: (0)	I've noticed this is common on all the actual M cars - I think it has something to do with the DCT's relationship with the ECU (causing ignition to retard timing to slow the RPM faster to shift faster) and thus creates a anti lag effect similar to that of the new flash tune antilags. If I were to guess- they both retard timing heavily to create boost, one (flashed M235i) does it to limit RPM climb during boost build up and the other (M2 that makes this sound) does it to actively lower RPM between shifts but with the same mechanism (deep negative timing - essentially running gas through the cylinder and out while engine braking hard off the compression phase). N55 M2 w/ 6MT models probably share the same ECU as the DCT M2 and and have a similar ignition retard function on shifts because it has auto rev match, which does the same quick reduction of RPM mid shift. My 2 cents. Programming this in would likely go hand in hand with auto rev match features. It also may not be possible to tune in this condition to our ECUS. Could someone from protuning freaks mhd or other tuning company with an understanding of both platforms pitch in? __________________ 14' Alpine White M235i 6MT, BM3 Stg2+, VRSF DP-CP-FMIC, Dinan Muffler, GFB DV+, 3.5 bar MAP, Dorch Stg1 HPFP, NGK 97506, BM3 Flexfuel Kit, CDV delete, KW V3, EDC delete, Powerflex Camber LCA bushings, VMR 801 18x8.5/9.5 et45, Conti Extremecontact 235/265 Next step: M2 Competition or Manual Supra MKV build Summer 2022
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02-02-2022, 11:08 AM	#100
dalderks Enlisted Member 14 Rep 38 Posts Drives: BMW M235i Join Date: Feb 2020 Location: Washington iTrader: (0)	MHD released the update yesterday! (For those that don't monitor the F30 forum) https://www.instagram.com/tv/CZcfbzC...dium=copy_link
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02-04-2022, 12:53 AM	#104
rtl32 Private First Class 73 Rep 196 Posts Drives: M235i 6MT Join Date: Nov 2020 Location: NJ iTrader: (0)	I'm quoting Cary Jordan from a thread a while back: https://f80.bimmerpost.com/forums/sh....php?t=1208681 (Post 14) "I haven't been able to confirm my theory, but I think the DME is re-using charge pipe boost on throttle lift for anti-lag purposes by allowing the throttle plate to stay open on lift-off allowing the engine to ingest the excess boost, which pushes the excess boost through to the turbine section, helping to keep the turbos spooled and the EWGs are helping to facilitate this as well by either bypassing the turbine wheel or allowing the pressure to flow through the turbine wheel depending on what conditions merit. The throttle plate remaining open on throttle lift-off is confirmed by me through datalogs. This would also help explain the brap or "farts" that you hear during a lift-off event with significant boost pressures. I suspect that there might be some valve overlap trickery going on during these events as well. This would also help explain the "swoosh" sound we hear in the intakes from the sound of the excess boost slipping back past the throttle plate. So, by doing this, BMW has achieved two things. A form of anti-lag as well as keeping the excess boost pressure from backing back up in the turbos without the use of a diverter valve. Brilliant, actually." Sounds like because the S55 does not have a charge side pressure discharge (BOV or recirculating DV like we have on the N55), it creates situations where the pressure flows out of the engine quickly rather than in a manner that would produce useable torque by retarding the timing heavily while keeping the throttle plate open temporarily following a throttle lift off. AKA, blow the mixture through with such delayed combustion that as the exhaust valve opens it blows up and out of the cylinder as the piston travels up in the exhaust phase instead of during it's normal combustion/power phase. No power, crazy sound, turbulent gasses still working on the turbine. As CJ said, this is similar to a traditional rally type antilag that works by moving the combustion of the air/fuel mixture from the cylinder to the actual turbocharger housing pre turbine, to maintain the wheel speed and hence immediate booster throttle response as the driver gets back on the throttle. Another post in this thread much earlier on suggested that this braap sound might happen because of a change in the exhaust valve matrix, which even in a vanos/timing chain controlled setup is not possible because it is SO far out of the normal operation (would require rotations not degrees of the camshaft to complete). I think that logic was on the right path but instead of physically allowing the normal combustion process to escape with altered exhaust valves, I think it just alters the timing of the combustion instead. HERE is my proposal: MHD users with this at their disposal! Log a few vigorous runs with (both settings) and then without this feature enabled with throttle angle, MAP, (both intake manifold and charge pipe) and any fuel injector duty cycle channels open. Let's see if there is any difference in both the throttle plate behavior and the boost trends in the logs of each mode. If we see boost being held longer with less throttle snapback on off throttle, we might be able to suspect this mode is actually just disabling the DV control and forcing everything into the engine with slight updates to make that situation safer for the longevity of the turbos. __________________ 14' Alpine White M235i 6MT, BM3 Stg2+, VRSF DP-CP-FMIC, Dinan Muffler, GFB DV+, 3.5 bar MAP, Dorch Stg1 HPFP, NGK 97506, BM3 Flexfuel Kit, CDV delete, KW V3, EDC delete, Powerflex Camber LCA bushings, VMR 801 18x8.5/9.5 et45, Conti Extremecontact 235/265 Next step: M2 Competition or Manual Supra MKV build Summer 2022
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02-07-2022, 04:09 AM	#106
Thomas590 Private 27 Rep 86 Posts Drives: A3 2.0T Join Date: Sep 2019 Location: EU iTrader: (0)	Anyone yet tried with catless?
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02-18-2022, 03:24 AM	#109
sl0w_N55 Enlisted Member 2 Rep 36 Posts Drives: 2015 Bmw M235i x-drive Join Date: Jan 2022 Location: IL iTrader: (0)	Little late but MHD just added the Braap feature for all N55's. You can choose between short and long(M2 vs M2C sound). __________________ sl0w_N55 -MHD stage 2 -Jordan Carry custom e85 tuned
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