What's the chamber for? The one on top of the stock intake box held by 2 screws? Is there an adverse effect if left uncovered?

 

picture of this thing you call the "top chamber?"

 

Check out my threads on "pointless airbox mod" and not-so-pointless airbox mod.

Basically the cover is to a sealed off sound chamber. Removed the lid, and you get induction noise. Actually sounds pretty good.

 

could just be me, but after i removed that lid to get a deeper sound, i also noticed my mpg reduce by a couple mpg

 

It mustve been due to cooler air induction from the removal of the lid. Cold air equals more Power but less mpg and warmer hotter air will increase mpg but so with loss in power.

 

It is more likely that removing it screwed up the carefully engineered intake tuning. I havent studied the Fit intake system yet, but the one on my Tundra is totally dependent upon chamber volume tuning to maximize torque at different rpm's. I suspect the Fit uses this in harmony with i-Vtec.

 

Top chamber is not open to anything if the box is left alone. Its simply an open space to buffer intake resonation. I modded my air box to use this opening as an alternative path of intake air to enter the air box. OP is referring simply to the lid.

 

so the sound chamber isn't open to the filter? It can be cut to let more air in and sound better?