Exhaust drone (Helmholtz chamber)

[jeff71]

Anyone have any experience with a Helmholtz Chamber?

One of the things I’m super annoyed by is exhaust drone or resonance. I want to be able to have a conversation without yelling when driving & not into loud exhaust in my cars.

I noticed Roadster Shop has been doing these for sometime on their builds, Magnaflow now offers this muffler as a kit.

https://www.magnaflow.com/products/14009-magnaflow-5-x-8in-oval-straight-through-performance-exhaust-muffler-14009




https://www.youtube.com/watch?v=MSMzTT7y_bo

[ScotI]

The problem w/the 'universal' set-up would be dialing the set-up to the frequency of the 'drone'.

Changing the chamber length/size impacts the outcome. A clamped-on tubing extension should be an easy option for helping dial things in though.

[WSSix]

Just watched a video on youtube from Summit displaying the new NDT kit from Magnaflow. Looks somewhat adjustable and might work for you. If you can fab, you may want to consider learning the science behind it to make your own solution. It's not difficult really. There are apps that can provide the frequency info necessary for the calculations. Packaging may be the hardest part.

[RDuke]

I did one with mine. In wiring phase at the moment so I don't know the impact yet.

https://i.postimg.cc/YSSK3gCm/Photo-Sep-30-21-10-54-14-AM.jpg (https://postimg.cc/0zhB5zm8)

I did all the math calcs for mine. With a LS3, tire height, transmission gearing, etc. I basically ended up with the following numbers:

Drone/Cruise RPM: Inches needed for tube:
1,900 : 25.65"
2,000 : 25.32"
2,100 : 24.11"
2,200 : 23.01"
2,300 : 22.01"