Rule out the CAI---put your stock box back on while you're trying to figure out the problem. Could be pulleys or maybe the transmission itself...if there's a leak, even a small one, they can squeal under load.

Either that or someone sold you whistle tips for your exhaust! Ok...I'm severely dating myself there.... that was a fad about 10 years ago...lol

 

Mine does the same thing on my 12. Always has and I'm with stock airbox. I think it may be either intake or a minor belt slip/squeak under heavy throttle

 

http://www.youtube.com/watch?v=9dRWgVo0FHE From :52 on = priceless examples of awesome and @ 1:35

 

Whoooo!!! Whoop!!!!!! Lol!! That's not the noise

 

Wondering if a programmer might fix it if they change the transmission shift points