Weird noise on high boost

[arootbeer]

This morning, I started hearing a "flapping" sound...for lack of a better word. Actually it sounds a lot like a muffled harley engine, "pop pop pop". I noticed I heard it when I pushed the pedal past 70% or so, so I thought I might have a hole in my exhaust somewhere. But then I noticed that I heard it whenever the boost guage shows >14 lbs. I think it's related to my lower IC hose, but I'm posting this to ask for suggestions.

The car still has normal power, no smoke whatsoever on this 50 degree morning, and the boost gauge response hasn't changed noticeably.

 

[jaydhall]

Stock airbox has a flap which opens when the air intake is restricted. My only guess.

 

[arootbeer]

You mean on the snow screen tube? If so, mine doesn't have the door...or the screen. Didn't come with one. Is there a flap in the box itself?

 

[runonbeer]

Pressure shockwave ricocheting off of a valve from one of these massive spikes?

 

[arootbeer]

No, it's not doing that anymore since I changed the air filter. Now I've got the normal 17-10-13/14 spike like everybody else /images/graemlins/tongue.gif

 

[jaydhall]

There is a flap on the box itself, yes.

 

[arootbeer]

I looked all around the box, but didn't see anything. Where is it located?

Anyway, when I got to the car this afternoon, the sound was gone. No amount of, ummm...spirited driving... /images/graemlins/grin.gif could coerce it back. I'll pull the belly pan tomorrow and take a look, though.

I opened the air box and poked around tonight, but couldn't find anything in there except filter oil /images/graemlins/tongue.gif