Well, I'm marginally dissapointed.
Let me tell you what I've noticed so far.
I'm using my maxitrip scan tool to monitor the trucks computer readings while I'm driving. It sits on top of the steering column.
First IA temps. It sucks, at least 10-20 degrees higher than the stock box at idle. I've recorded at least a 73degree IA with ambient temp of 36degree at idle. When driving on the highway the IA temp drops to ambient of 36. In essence even though I avoided cutting out the section facing the hot engine like the heat shielded CAI kits the temps are higher than stock. All temps are in celcius. Again if anyone has the full CAI from K&N I'm curious to know your IA temps at idle vs ambient temps.
Second performance. At first I thought it was good and noticable, but then I realized by monitoring the TPS sensor that I simply had my foot into it a bit harder. When I tried to figure out why, I realized today that it was because I liked the sound that the open box was making. If I drive with my foot at the same level(verified by monitoring TPS levels) as before mod, then I can't tell any difference - Highway cruzing or accelleration.
Third the sound. I like it. I find myself tromping it at every green light, just to hear that sound. It's addictave. Next time when your doing 100kms on the highway, just floor it until you hit the governer at 160kms. That sound is awesome!
Fourth fuel economy. IDK yet. It's too soon for me to tell, and I figure that because I'm addicted to that sound any gains in MPG are offset by my new lead foot. When I calm down next week, I'll look into fuel economy.
This is all with my stock used probably dirty air filter. My new K&N drop in hasn't arrived yet. I'll revisit this after it arrives.
Maybe I'll get one of those ported throttle bodies from Jantzer. IDK, I'll see what foreverfalcon40 says about his.
http://www.tahoeyukonforum.com/forum/showthread.php?t=16255
Anyways thanks for listening to my rants!