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      11-12-2021, 02:18 AM   #1
Irielion
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OPF delete difference

A lot of people are talking about deleting their OPF on the EU cars. What will be the difference? Will the car be a lot louder and how about the burbles? Or just another tone?
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      11-12-2021, 03:18 AM   #2
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EU car will sound more like an M2C from non OPF market.

Main benefit is EU OPF delete will liberate more oomph from the stock car, w/o needing to remap. EU car's ECU runs more aggressive fuel/boost/timing thatn non OPF cars. ;-)
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      11-12-2021, 12:24 PM   #3
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I have eliminated OPF and central silencer by installing Actuve Autowerke kit bought from
https://pureturbos.eu/aa-midpipe.html
I am very happy . Car with closed valves stays quiet . With open valves it is exceptional. You gain at least 15 hp.
You have to install LEIB emulator as well.
https://www.leib-engineering.de/en/l...mpetition-f87n or about every 50 km car goes into sleep mode (do not exceed 110 km per hour). You have to turn off the car and then turn it on again.
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      11-13-2021, 03:26 PM   #4
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Quote:
Originally Posted by Bee Pee View Post
EU car will sound more like an M2C from non OPF market.

Main benefit is EU OPF delete will liberate more oomph from the stock car, w/o needing to remap. EU car's ECU runs more aggressive fuel/boost/timing thatn non OPF cars. ;-)
Quote:
Originally Posted by Bee Pee View Post
EU car will sound more like an M2C from non OPF market.

Main benefit is EU OPF delete will liberate more oomph from the stock car, w/o needing to remap. EU car's ECU runs more aggressive fuel/boost/timing thatn non OPF cars. ;-)
So if you remove the OPF on a EU M2C, you will have more Horsepower? And the sound? How does the non OPF sounds if you compare it to the OPF version?
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      11-14-2021, 12:28 PM   #5
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      11-14-2021, 03:22 PM   #6
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Quote:
Originally Posted by Irielion View Post
Quote:
Originally Posted by Bee Pee View Post
EU car will sound more like an M2C from non OPF market.

Main benefit is EU OPF delete will liberate more oomph from the stock car, w/o needing to remap. EU car's ECU runs more aggressive fuel/boost/timing thatn non OPF cars. ;-)
Quote:
Originally Posted by Bee Pee View Post
EU car will sound more like an M2C from non OPF market.

Main benefit is EU OPF delete will liberate more oomph from the stock car, w/o needing to remap. EU car's ECU runs more aggressive fuel/boost/timing thatn non OPF cars. ;-)
So if you remove the OPF on a EU M2C, you will have more Horsepower? And the sound? How does the non OPF sounds if you compare it to the OPF version?
BMW quote the same performances and outputs with and without OPF.

OPF is considerably more of a restriction than secondary cats of non OPF cars.

Remove OPF and the stock ECU will be aiming at higher parameters. Without the restriction the car will be more responsive and will be able to hit and maintain higher targets wo heat issues
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      11-21-2021, 02:58 PM   #7
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Quote:
Originally Posted by Bee Pee View Post
EU car will sound more like an M2C from non OPF market.

Main benefit is EU OPF delete will liberate more oomph from the stock car, w/o needing to remap. EU car's ECU runs more aggressive fuel/boost/timing thatn non OPF cars. ;-)
Incorrect, the OPF cars have no or completely insignificant changes (if any) to the maps that determine power levels from boost, fuel, or timing.

Boost request, fuel, and ignition timing are the same for both models.
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      11-23-2021, 03:32 AM   #8
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Quote:
Originally Posted by Enabled View Post
Incorrect, the OPF cars have no or completely insignificant changes (if any) to the maps that determine power levels from boost, fuel, or timing.

Boost request, fuel, and ignition timing are the same for both models.
OPF cars are designed to run with a higher back pressure than non-OPF/2nd cat equivalents. OPF cars "micro-manage" - requiring additional back pressure sensors - to monitor OPF efficiency.

Modern lean burn turbocharged are very sensitive to back pressure. Removal of any blockage ie decatting is a known path to improve performance w/o remapping.

OPF construction |(pre-cat + baffled honeycomb filter) is designed to create a higher back pressure than a 2nd cat. Like for like, removal of OPF vs removal of 2nd cat - the performance benefits with respective std ECU tunes will be greater for OPF version than that of 2nd cat delete.
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      11-23-2021, 08:54 AM   #9
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But the thing is, both the cars have the same internal torque calculations, and the same parameters, settings, and PID controllers for the turbo to build that torque.

The ECU control on this is completely different than cars in the past, there are no boost maps, and everything is calculated live. Everything follows the internal torque model, and that is unchanged between the two cars. The OPF car does not aim for higher parameters.
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      12-16-2021, 03:31 AM   #10
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A few days ago the deleted the OPF on my M2C. The car is so much louder!
Be careful if you delete the OPF on European cars.
I got the Miltek Equal Lenght Exhaust and it's almost so loud as my previous M2 OG which was straightpiped. And I still got the original cats.

You also have to like the burbles / pops and bangs. These are so much louder and sometimes too long. My car is running on stock software and went after some hard runs in limp mode. But we solved this with the Leib connectors.
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      12-18-2021, 02:45 AM   #11
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Quote:
Originally Posted by Irielion View Post
A lot of people are talking about deleting their OPF on the EU cars. What will be the difference? Will the car be a lot louder and how about the burbles? Or just another tone?
Deleted OPF on mine. got the resonated AA EL midpipe and its not very loud, so I will be removing the resonators.
The biggest difference for me is the throttle response. Huge difference compared to before.
You are also allowing your motor to breath alot more, so its definitely healthier for the motor.
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      12-18-2021, 02:47 AM   #12
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Quote:
Originally Posted by Betaone View Post



Is this resonated on unresonated?
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      12-19-2021, 01:54 AM   #13
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Quote:
Originally Posted by Bee Pee View Post
OPF cars are designed to run with a higher back pressure than non-OPF/2nd cat equivalents. OPF cars "micro-manage" - requiring additional back pressure sensors - to monitor OPF efficiency.

Modern lean burn turbocharged are very sensitive to back pressure. Removal of any blockage ie decatting is a known path to improve performance w/o remapping.

OPF construction |(pre-cat + baffled honeycomb filter) is designed to create a higher back pressure than a 2nd cat. Like for like, removal of OPF vs removal of 2nd cat - the performance benefits with respective std ECU tunes will be greater for OPF version than that of 2nd cat delete.
From what I know already '3 years ago' the OPF engines run a tad higher boost than the non OPF engine to compensate for that obstruction... Dunno the exact differences but I stated them here somewhere '3 years ago'....

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      12-19-2021, 01:55 AM   #14
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Quote:
Originally Posted by Irielion View Post
A few days ago the deleted the OPF on my M2C. The car is so much louder!
Be careful if you delete the OPF on European cars.
I got the Miltek Equal Lenght Exhaust and it's almost so loud as my previous M2 OG which was straightpiped. And I still got the original cats.

You also have to like the burbles / pops and bangs. These are so much louder and sometimes too long. My car is running on stock software and went after some hard runs in limp mode. But we solved this with the Leib connectors.
Do you have some kind of footage please?

Thanks

Cheers
Robin
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      12-19-2021, 12:02 PM   #15
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Quote:
Originally Posted by Robin_NL View Post
Quote:
Originally Posted by Bee Pee View Post
OPF cars are designed to run with a higher back pressure than non-OPF/2nd cat equivalents. OPF cars "micro-manage" - requiring additional back pressure sensors - to monitor OPF efficiency.

Modern lean burn turbocharged are very sensitive to back pressure. Removal of any blockage ie decatting is a known path to improve performance w/o remapping.

OPF construction |(pre-cat + baffled honeycomb filter) is designed to create a higher back pressure than a 2nd cat. Like for like, removal of OPF vs removal of 2nd cat - the performance benefits with respective std ECU tunes will be greater for OPF version than that of 2nd cat delete.
From what I know already '3 years ago' the OPF engines run a tad higher boost than the non OPF engine to compensate for that obstruction... Dunno the exact differences but I stated them here somewhere '3 years ago'....

Cheers
Robin
I specifically recall someone (during M2C initial production) mentioning that the OPF cars run 0.5 bar higher boost, but there wasn't any evidence supporting it.

I am curious to know if the non-OPF cars still put down much more power to the wheels than OPF cars regardless of the tune, hence the strong stock whp numbers observed here in the US.
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      04-12-2022, 08:14 PM   #16
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Quote:
Originally Posted by Irielion View Post
A few days ago the deleted the OPF on my M2C. The car is so much louder!
Be careful if you delete the OPF on European cars.
I got the Miltek Equal Lenght Exhaust and it's almost so loud as my previous M2 OG which was straightpiped. And I still got the original cats.

You also have to like the burbles / pops and bangs. These are so much louder and sometimes too long. My car is running on stock software and went after some hard runs in limp mode. But we solved this with the Leib connectors.
Hey buddy, mine is a 2018 M2C, same set up as yours (Milltek EL), OPF delete, also installed Leib OPF Deleter, but it doesn't work for me. I still get the CEL and limp mode when I go hard driving. I get even more frustrated when the people at LEIB Engineering does not reply my questions/concerns about it.

I did every software reset/ OPF replacement via ISTA+ (according to their instructions) but to no avail. BM3 tuning is the only solution I guess.


Thanks!
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