Ok, so I took apart my upper fairing today to work on my custom LED setup, and I came across something strange. About 6 inches inside the Ram Air Duct, there is a hole in the bottom of the duct that leads to small empty container (~3 cu. in.). The container has no sensors and no moving parts, so it is completely passive in whatever it does. It makes no sense to me. I could see it as being an extra air supply for quick throttle response if it were behind the filter, but it is not. If anything the grommet and corresponding hole just simply create air turbulence, slightly hindering would-be performance (though not enough to be noticeable).

 

It's a sound anti-resonation chamber. My F4i had 1 in each side. Also acts as a moisture/ water drain catch tank. There should be a little hole in the bottom. If you remove it, you will hear the intake noise more. Sounds like a slight growling. Some people like it and get rid of a few ounces of weight. You'll need to plug the hole with something. I removed mine.

 

Hmm, yeah, definately going to just not re-install that particular device. I'm installing 2 LEDs inside the ram air duct that are sound sensitive... that way they brighten up as the engine gets louder. Should be interesting. Maybe I will use that hole as the install point.

 

don't forget to post pics whe you are done with the lights!!