i have an 06 qc hemi 4x4, and when I decide to have some fun with it and get it up to rpms over 4500-5000, it starts to make a whistle or whining sound. I'm assuming this is from the engine working harder to suck in more air. Would a CAI and a catback lessen this and free up lots of high end power?

 

i have the same "problem" i dunno if it really is a problem. i think its just normal.

 

The CAI would make the sucking sound a little more noticeable. It may not be the same sound, but you will hear that filter suck more air. The cat-back is going to be loud enought that it may drown out the sound. I don't know what the noise you are hearing is, though and these aren't going to "fix" the problem.

 

My turbo does that all the time.

 

well doyy, diesels got turbos. but damn does that sound cool. Put a big beefy turbo and a blow off valve and it sounds wicked.