I'm wanting to buy an intake but don't want to make the car too much louder. I'm looking at the Stillen. Is it any louder than the others? Are some quieter than others?

 

All are about the same. Frankencar's is a little different in that it has a midpipe which does indeed make the car considerably louder. The Frankencar is not horribly loud until about 3500 rpm's where the throaty growl pops in. All the others sound the same including the FrankenCar without the midpipe. They are only louder under Wide open throttle, otherwise they are just as quiet as stock.

 

ditto on that, thats very acurate info on the intakes. i have frankencar midpipe, combined with the stillen velocity stack and cone.
it kinda quiets it down in the higher rpm range(5400rpm and above) the roaring intake noise stops and just revs to redline, im guessing its due to the stillen cone, since it smooths out the airflow a little bit. the roar of the intake that u hear is caused by air turbulence. (blow on the top of a beer bottle)

 

my injen sounds stock, unless you open the throttle to 2/3 or more. When i do that, the car scares bird outta the trees as i drive under. I put a decibel meter to my injen, i got 103 out the drivers window.

 

103 db! sweet as long as its quiet under normal driving i dont car how loud it gets, hey it woulndt bother me if it got to over 120+db at WOT.

 

might also depend on whether you have the 3.0 or 3.5 maxima. I know for a fact that the frankencar sounds different on the two cars.. prolly cause the 3.5 is sucking in more air