Has anyone tried to remove the Hemholtz resonator (part #13-195A) from the stock intake accordian tube? I'd like to give this a try, but it leaves a big hole that must be capped. With the resonator gone the intake should be quite a bit louder, but I'm only speculating here. If you've done this before, please share your experience here.

Here's one of the few threads I've found on the part in question:
https://www.rx8club.com/series-i-tech-garage-22/stock-intake-resonance-chamber-plugging-hole-40799/

 

^agreed.

 

What is it there for?

 

Basically used to reduce noise by canceling certain sound waves.
You would need a way to cap the intake if you do remove the chamber, but I wouldn't bother removing the chamber unless you're curious.

 

If you're looking for a little more sound, remove the 2 plates and 1 screen inside the airbox. Hell, it might even add 0.005 hp

 

could always remove it and just tape the hole shut good and start it up to see if it sounds different..then decide if you want to buy a cap...

 

if you are looking for a cap, go to a drug store and look around for bottoms of canes. canes as in walking sticks for old or disabled people, that kind of cane. they are black round and come in a few different sizes in 4 packs for about $2. i found out that some of them were perfect for covering my fittings on the exposed adapters of my on-board-air setup i had on my tacoma. silly little things like this look pro and are dirt cheap. BTW i have to give credit to the find to my father, had a package in his truck ( he used a cane ) and noticed it would cover perfectly.