reducing engine noise

[E46m3zcp]

Hey,

I installed a set of megan catless headers on my track m3 that already had a magnaflow catback. I'm looking to go to an event at a track that has sound restrictions (92 dB fly by measured from random points) and currently, I'm afraid I would get banned. A friend suggests I replace the box in the Magnaflow system with ar20 resonators.

Anybody has had the same problem, and how did you solve it?

current engine sound (I like it, but its loud)

https://youtube.com/shorts/9qfrfXb4_Co?is=Dpbpp_00C9ESjNOc

[AWE46M3]

I bought the magnaflow catback when my first got my car. That exhaust sounds incredible (and the tips look great out the back) but the drone was unbearable. I truly hated driving the car, especially on the freeway. I'm sure it sounds much louder to you in the car than it actually is outside.

Back to the topic at hand:

I'd install a resonator in the section 2 (the biggest one that will fit - I think Borla makes a great option) similar to how Super Sprint has a resonator after the H pipe (or x pipe in your case).

[01SG]

I've often seen people get those exhaust pipes that point toward the ground to pass sound restrictions. Not sure if they are easily added or an entire muffler that is specially made, but perhaps worth looking into.

[Sharocks]

Get Vibrant Ultra Quiet resonators installed.

Should bring it down a bit.

[E46m3zcp]

Can anyone tell what the "box" on section 1 of the Magnaflow is? Is it a double resonator?

[E46m3zcp]

I bought the magnaflow catback when my first got my car. That exhaust sounds incredible (and the tips look great out the back) but the drone was unbearable. I truly hated driving the car, especially on the freeway. I'm sure it sounds much louder to you in the car than it actually is outside.

Back to the topic at hand:

I'd install a resonator in the section 2 (the biggest one that will fit - I think Borla makes a great option) similar to how Super Sprint has a resonator after the H pipe (or x pipe in your case).

did you actually do that and it got quieter or is this an idea you say I should try? What's that image? It does not look like the magnaflow for the e46 m3 that I have... are you just showing the kind of resonator?

[AWE46M3]

did you actually do that and it got quieter or is this an idea you say I should try? What's that image? It does not look like the magnaflow for the e46 m3 that I have... are you just showing the kind of resonator?

That screenshot is of the twin-tube resonated Supersprint Section 2. I’m currently running this setup on my car. My recommendation is based on my actual experience with it tangentially but primarily to show you where you can add another resonator downstream.

The SS Section 2 can serve as a good point of reference for where you could add a resonator to the Section 2 of your Magnaflow system.

Since your Section 1 already has a fairly beefy resonator, your Section 2 is really the missing piece - it currently has no resonators, just the X-pipe. Adding a resonator there should reduce the overall sound output enough to make a meaningful difference.

From my perspective, the “box” on your Section 1 is probably doing more to muffle the exhaust than two individual AR20s would. That’s why I’d be inclined to add a resonator to Section 2 rather than trying to add more muffling to Section 1.