Like the title says, what is the difference between the different stages? I have been looking into different air intake's, SE heavy breather/K&N, and am now kinda unsure what the differences are between the different stages.

Also why is K&N more expensive then the SE heavy breather?

 

Size and how much air they will flow. Stage 1 is generaly good for pipes and a mild cam on otherwise pretty much stock motors. Stage 2 is generaly for more involved builds that are really capable of flowing and useing more air.

 

about $200 bucks