Purchased pre owned m2 with weird exhaust mod- what is it

capeie · 11-23-2022, 10:55 AM

Hey guys.
Glad to join you guys on this forum- just picked up a car I've wanted for a very long time- the 2018 m2 with very low milage. The previous owner old me he's installed a catback exhaust system on the car.

Only issue is, it looks off. It looks like he did a muffler delete(?), and only one exhaust pipe on each side is actually connected to the exhaust tips and the other is welded shut.

Is this exhaust setup a concern? Never seen this before and havent found anything like this online. Seems like it wasn't done properly and might be harmful to the engine- thoughts? I was thinking of getting the M performance exhaust for it anyways, so should i just swap out to be safe?

Driver's side exhaust

Passenger side exhaust

Whole setup

WedgeSalad · 11-23-2022, 11:28 AM

The welded shut portion is a helmholtz resonator. It was probably custom built by a muffler shop and shouldn't hurt the car. Those chambers are used to alter the exhaust sound and reduce drone.

https://www.cjponyparts.com/resource...nator-exhausts

track.n.trail · 11-29-2022, 03:24 PM

As WedgeSalad said those are Hemholtz Resonators. I had them on my Camaro SS 1LE - they work well to reduce drone. It definitely it not going to hurt your car.

How does it sound?

CalAcacian · 11-30-2022, 02:41 PM

Agreed with the posters above. As long as you are happy with the tone of the exhaust and the level or lack thereof of drone, you are fine to keep this system as is.

AmuroRay · 11-30-2022, 03:02 PM

Agree with the agreement, of the agreement of the agreement, they Helmholtz resonators. Please post a sound clip

11-23-2022, 10:55 AM	#1
capeie New Member 13 Rep 14 Posts Drives: 2018 M2 LCI Join Date: Nov 2022 Location: Seattle iTrader: (0)	Purchased pre owned m2 with weird exhaust mod- what is it Hey guys. Glad to join you guys on this forum- just picked up a car I've wanted for a very long time- the 2018 m2 with very low milage. The previous owner old me he's installed a catback exhaust system on the car. Only issue is, it looks off. It looks like he did a muffler delete(?), and only one exhaust pipe on each side is actually connected to the exhaust tips and the other is welded shut. Is this exhaust setup a concern? Never seen this before and havent found anything like this online. Seems like it wasn't done properly and might be harmful to the engine- thoughts? I was thinking of getting the M performance exhaust for it anyways, so should i just swap out to be safe? Driver's side exhaust Passenger side exhaust Whole setup Last edited by capeie; 11-23-2022 at 11:33 AM..
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11-23-2022, 11:28 AM	#2
WedgeSalad First Lieutenant 281 Rep 309 Posts Drives: 2018 F87 M2 Join Date: Aug 2018 Location: SoCal iTrader: (0)	The welded shut portion is a helmholtz resonator. It was probably custom built by a muffler shop and shouldn't hurt the car. Those chambers are used to alter the exhaust sound and reduce drone. https://www.cjponyparts.com/resource...nator-exhausts
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11-29-2022, 03:24 PM	#3
track.n.trail Private First Class 62 Rep 132 Posts Drives: OG M2 Join Date: Jan 2019 Location: San Francisco, CA iTrader: (0) Garage List 2016 BMW 340i [0.00]	As WedgeSalad said those are Hemholtz Resonators. I had them on my Camaro SS 1LE - they work well to reduce drone. It definitely it not going to hurt your car. How does it sound? __________________ M2 - TC Kline DA Coilovers - Apex SM-10s - 265 RS-4s - Dinan Intake - BM3 - CSF Intercooler - VRSF CP Previous: 6th Gen Camaro SS 1LE \| 2020 JLUR Wrangler \| F30 340i \| B7 Audi A4 APR Tuned \| E46 330ci Instagram @track.n.trail
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11-30-2022, 02:41 PM	#4
CalAcacian Lieutenant 550 Rep 570 Posts Drives: 2018 M2 Join Date: Sep 2020 Location: Orange County, California iTrader: (0)	Agreed with the posters above. As long as you are happy with the tone of the exhaust and the level or lack thereof of drone, you are fine to keep this system as is.
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11-30-2022, 03:02 PM	#5
AmuroRay Brigadier General 2283 Rep 4,146 Posts Drives: M235i Join Date: Aug 2019 Location: Florida iTrader: (0)	Agree with the agreement, of the agreement of the agreement, they Helmholtz resonators. Please post a sound clip
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