Helmholtz Resonator

[Edwin Spangler]

Ive always liked making custom exhaust for things. Got bored yesterday and soon enough a pile of scrap metal was at my feet. Needed to do something with it.

This 'idea' is at the very beginning stages, thats why its just scrap. Welding in high winds... Blah blah all them excuses. It holds water so Im happy.

The usual reason to have one of these is to reduce exhaust drone inside a vehicle but depending on a million factors, you can use it to change the sound of the exhaust. It definitely pulls the note away from 'industrial engine sound' and gave it a more unique note. Nearing 'nasty' description.

Not sure anyone is even interested but here it is anyhow. Open ( requesting) to suggestion and comments. Ive done absolutely no research or calculations which one would usually do before doing this.

 

[ezcome-ezgo]

What did you say? I can't hear you.

 

[Hellion]

Never heard of the guy, but make sure you decouple the Heisenberg Compensators.

When you say nasty, is that a good nasty or a bad nasty? No need for going deaf or developing tinnitus before one’s time, but everyone loves a good exhaust rumble. We‘re gonna need a video ‘afore too long.

 

[Sparkwizard]

I used to run VW air cooled things. Without the original mufflers, they were very annoying and noisy. Is this one of those?

 

[Edwin Spangler]

No no, not going for loud. Just different and unlike an industrial engine sound.

Nasty.. Cant think of any other way to describe it. Think; metallic-less raspy. Listen... BERRRRRRRRWAHHH , like that...

Hellion, I actually have "Eagle's syndrome" so I hate loud engines.

Post a vid later for sure.

 

[Edwin Spangler]

Welp... It was such a failure that I didnt even bother to record anything.

Certainly needs to be longer, wider, and a single pipe. For another day I guess.

So I made this monstrosity today... This one, Im happy with the results. Nice and quiet.

Two layers of internal baffling and another on the outside.

I wish I would have got some progress pics cause itd probably have been pretty interesting but you know how it is when you gather a pile of crap and get working. "Cant stop now...."

Lol Ill draw up a diagram in paint to show the 'internals'.

 

[Edwin Spangler]

 

[Edwin Spangler]

A little more explaination because theres even more detail in this POS...

Main pipe and #1 and 2 baffles are capped at the end.

Holes in the main pipe face upwards.

1st baffle holes face downwards.

2nd baffle faces upwards.

Then the exit baffle faces the ground.

I was considering packing it with fiber but I started to worry about restriction. I dont feel there is any right now but packed with fiberglass might have slowed flow. No real need for it anyway, its pretty quiet. You can clearly hear the engine is louder.

 

[Denny]

View attachment 162433

But what is the hair for at the bottom?