What is that sound?

[CoronaRaptor]

Awesome news!

 

[AnamnesisV]

Hey OP. Did you eliminate the sound completely? I got a 2011 Gen 1 with the stock air box and it’s making the same sound around 1st to 3rd gear.

 

[MurderedOutSVT]

Wow what a find!. I was leaning towards a possible tuning in the shift points as you originally suggested. My truck has a whipple and originally was tuned to shift hard and would make truck hop even. I Just had it returned and it shifts soo much better but now makes a sound as it shifts, it's sorta like a fast woosh! or shooof! sound and it's much more precise and smooth. I don't mind the sound and kinda like it, but the point I was trying to make is this is why I was thinking it might of been something with your shift points.
I have a K&N CAI but only sound I hear from that is an air suction sound when getting on it. Air is being sucked in so fast I can definitely see how a lid that's a bit short would act like a reed and cause vibrations. At least it wasn't causing a loud whistle lol

What kind of tune did you get to fix the hard shift? Mine shifts stupid hard sometimes, like yours, it will hop. I have a Procharger DS-1

 

[Canuck714]

Received and installed the stock airbox with a K&N filter, it resolved the sound issue completely! Can't believe how much better it sounds now, none of the drone and no more hum/vibration. I can still hear the exhaust, just don't have the cab resonating loudness. AFE + Borla = no bueno...at least for my truck!

The best part of this return to stock mod you did was you probably dropped your Intake Air Temp 20 degrees.
I have a HP Tuners gauge on the dash monitoring a few things and IAT is one of them. Going from a "cold air intake" to stock put lower temp into the intake.
CAI only shows good numbers on a Dyno where they control air temp. Under the hood of your truck temps soar...lol

I've said this before, but a Ford engineer told me at Baja, the intake was designed to support north of 500hp so why would you put an oily filter sucking hot air through it on a stock engine..lol