On many stock applications (including the 2007 LC9 I am working on) there are one or two molded chambers in the intake, after the mass flow sensor and before the throttle body.

Do these chambers do anything? None of the aftermarket system have them?

 

They are called Helmzhold chambers or something similar. They help keep noise down, is the simplest answer I can give you.

 

Yep, just baffles to reduce noise.