I have an '04 hemi and was thinking about getting the type of intake deal that has the tube connected to the filter without a box. It seems to me like these filters would get dirty pretty quick since they are not inside the box. Is this true? I drive on dirt roads frequently and don't want to be cleaning my filter out all the time. Also, how much hp and torque increase could I expect? Thanks a lot.

 

Here's the deal with the 04 hemi and intakes. The engine does not recalibrate for increased air flow, but it does respond to air temperature. So the best you can do is to put the intake somewhere it's going to take in the coldest air. if the filter system you're talking about is an underhood intake, no gain, perhaps even a lose depending on where it's located. The stock system can be modified to take in the coolest air possible and use a drop-in performance filter like a K&N.