[ng20_]

Goal: I wanna make my car louder but not kill it and make it sound like a straightpiped gti

MPE is not good for the price, can't do dp or muffler bc i live in mass, aftermarket exhausts are meh, so thinking about the $ to sound ratio and the last real option, seems like I should concider a res delete.

So... below are my questions and concerns.

1. Seems like there is the opf on the US cars as some say there arnt. (I looked under my car… it’s there) I assume it is maybe less effective than the Euro one. This would explain its efficacy as a second cat, ie euro has harsher standards, and their version has less burlbes, sound, and performance. I assume removing the US OPF wouldn’t give any noticeable performance boost, but will affect back pressure and sound noticbly. But I bet the US would have less of a delta (change) in backpreasure than if you were to compair it to the EU, so it may not throw a code. Some call the opf a res some call it the second cat but i guess it’s both.

2. If I were to remove the res and the OPF, what are the ups and downs? Some say drone, some say no drone. The major point is exactly what they deleted. The OPF and the Res? Just the res? Just the OPF?

3. Is there a reason to remove one and not the other? I cant seem to find any videos or posts that would promote doing one over the other.

4. Smell. As it does provide some cat like properties/characterisitcs, will it have much noticeable smell in the cabin or out. Removing the cat def will… but will there be any serious smell increase… asking more to people who have done this.

5. Emmsions… will it screw me (ie will i pass mass inspection and no CEL ETC)

6. Drone? I drive for fun in sport so don’t care all too much as long as it’s not conversation breaking. I sit in eco on highways when I'm just trying to drive chill, so that's most important.

7. Any good clips of a before and after would be nice too. I have seen the ones on youtube, but you dont always have the story behind them/ ask the person questions on what they did exactly. Comments on vids dont always do justice either.

all opnions and thoughts welcome!

[murderedg20]

Why can't you do muffler delete in mass? It doesn't impact your emissions (as far as I'm aware). I will try to remember to take a video of my muffler delete sometime this week. I have a 2019 330i with muffler delete and am very happy with it. Only get drone when RPMs are hovering between 2 and 3 but other than that no. Silent on the highway when I'm going ~75, sounds great when I floor it.

[BmwDriverStockholm]

You made so many assumptions in your post =)
If you want decent sound and your want to be able to pass emissions there are several good ways to get decent sound and performance:
- Get 300-cell downpipe from a premium part manufacturer AKA "no CEL guarantee" and get a catback exhaust
- Get 200-cell downpipe and catback exhaust and Stage 2 tune
- Get 200-cell downpipe and axleback exhaust and Stage 2 tune

Replacing standard exhaust (OPF or secondary cat) will significantly boost torque/power in higher RPM. It has almost no difference in the RPM range of 2000-4000.

Because you have 2019 330i I recommend you the second option. You will not be disappointed with the power gains!

BTW I think a "resonator" is there for a reason. If you delete just the res - I bet you will get weird tones in your exhaust which will not be nice for the ears

[ng20_]

Originally Posted by murderedg20

Why can't you do muffler delete in mass? It doesn't impact your emissions (as far as I'm aware). I will try to remember to take a video of my muffler delete sometime this week. I have a 2019 330i with muffler delete and am very happy with it. Only get drone when RPMs are hovering between 2 and 3 but other than that no. Silent on the highway when I'm going ~75, sounds great when I floor it.

MASSACHUSETTS
Laws of Massachusetts: General Laws

Chapter 90 § 7. Brakes, Lights and Other Equipment; Standards.

Every motor vehicle so operated shall be provided with a muffler or other suitable device to prevent unnecessary noise and with a suitable bell, horn or other means of signaling, with suitable lamps, and with a lock, key or other device to prevent such vehicle from being set in motion by unauthorized persons, or otherwise contrary to the will of the owner or person in charge thereof.

Chapter 90 § 16. Offensive or illegal operation of motor vehicles

No person shall use a muffler cut-out or by-pass. No person shall operate a motor vehicle on any way which motor vehicle is equipped (1) with a muffler from which the baffle plates, screens or other original internal parts have been removed and not replaced; or (2) with an exhaust system which has been modified in a manner which will amplify or increase the noise emitted by the exhaust.

ty for your input! Its much easier to get away with the OPF delete than the muffler del. Some places don't care. Some do, simulat legality of tint, if u get a shitty cop ur done, if you get one where they are nice, ur fine. If I go for the res, its less obvious and hopefully then much easier to avoid any possible ticket.

[ng20_]

Originally Posted by BmwDriverStockholm

You made so many assumptions in your post =)
If you want decent sound and your want to be able to pass emissions there are several good ways to get decent sound and performance:
- Get 300-cell downpipe from a premium part manufacturer AKA "no CEL guarantee" and get a catback exhaust
- Get 200-cell downpipe and catback exhaust and Stage 2 tune
- Get 200-cell downpipe and axleback exhaust and Stage 2 tune

Replacing standard exhaust (OPF or secondary cat) will significantly boost torque/power in higher RPM. It has almost no difference in the RPM range of 2000-4000.

Because you have 2019 330i I recommend you the second option. You will not be disappointed with the power gains!

BTW I think a "resonator" is there for a reason. If you delete just the res - I bet you will get weird tones in your exhaust which will not be nice for the ears

Can't touch cat, on warrenty

So remove the opf but not the res? I could delete the opf, see how it sounds, if I am uphappy, take the res off after technically. If I hate both I could pay to have it put back on again. Still probably cheaper than a catback. But on that note do you reccomend any catbacks?

[BmwDriverStockholm]

Originally Posted by ng20_

Can't touch cat, on warrenty

So remove the opf but not the res? I could delete the opf, see how it sounds, if I am uphappy, take the res off after technically. If I hate both I could pay to have it put back on again. Still probably cheaper than a catback. But on that note do you reccomend any catbacks?

Given that your car is 2019 I assume your warranty is expiring pretty soon. I'd recommend you to wait until it expires and install the aftermarket downpipe. Without the downpipe, the exhaust will not sound great. The downpipe is the #1 impediment for power and sound.

[ng20_]

Originally Posted by BmwDriverStockholm

Given that your car is 2019 I assume your warranty is expiring pretty soon. I'd recommend you to wait until it expires and install the aftermarket downpipe. Without the downpipe, the exhaust will not sound great. The downpipe is the #1 impediment for power and sound.

Got an extended warranty on it :|

[jacky43211]

Im currently stage 2+ running a 200 catted downpipe pairing it with res delete. If you want a clip of the exhaust pm me on insta @g20.3er