OK, I give up.... what the jeck is up with the wierd, funky design of the air intake on my 2500HD air intake duct?! It's got a big bladder that hangs down and ducts that go nowhere and vent nothing. Even if I let my imagination run wild I can't come up with a reason that makes sense. Condesation? Heat generation? Engineers on rittalin? Does anybody know?

 

i think i heard it stores air. Someone else can further explain but if you get an aftermarket air intake for example Volant. It'll come with the same thing.

 

The bladder is an acoustic chamber that works like a resonator on a muffler. The idea is that certain "objectionable" sounds resonate and dissipate there rather than being heard by the occupants in the vehicle. It has been speculated that this chamber might improve throttle response, but I doubt it.

 

Its just a silencer.....it hinders performance if you sk me. Scrap it for a UPD or something else.

 

1BADHD is correct, I just put a MAC air induction kit on my 03' HD
they claim 18.7 rear wheel. How true it is I don't know, I plan to dyno and compair soon!

 

or there is true flow
www.trueflow.com