VERY Concerning noise...

What you're describing really sounds like a vacuum leak. Those are typically louder at certain throttle positions, wherever the engine is drawing the highest vacuum. The fact that you're hearing it more with a less restrictive air filter, and you're hearing it so much at the fender intake, indicates that it's sucking air somewhere within the intake tract, anywhere past the air filter box. Could be a bad gasket between assembled intake parts or poor connections on the boot from the filter box to the throttle body. To eliminate external sources (as opposed to within the intake tract) you can lightly spray carb cleaner on every vacuum hose connection in the engine bay, while the throttle is being held in a position where it makes the noise. If you have a leak anywhere there, it will momentarily go away with the carb cleaner. The you can do the same at all locations where the intake system parts bolt together, like at the throttle body, etc. If it's a bad seal or gasket you'll get the same result.

Well here's a video I took today. While sitting idle, if I get out of the car and put my ear next to the air dam, I can actually hear the constant faint screech up in the engine... and the video actually picks it up!! (if you listen close during the first 10 seconds, and pretty much every time I reach a red light)

And like I said, the sound is the loudest when I'm pressing on the gas, and it goes away when I'm not pressing the gas. In the video I pump the gas to emphasis that.

http://youtu.be/LKFEYhbBsuA

To be honest, it sounds perfectly normal with an aftermarket air filter. When I had my K&N air filter in my car you could clearly hear more "sucking" of air into the air box during acceleration. Sometimes I could even hold the throttle and make it whistle for a while. I always knew it was time to clean the air filter when I couldn't hear that noise.

I know that the video makes it sound like an "air" noise, but in real life it sounds metal.
Like when I'm sitting idle and stick my head next to the air dam, it sounds like metal spinning real fast.

DocL said:

To be honest, it sounds perfectly normal with an aftermarket air filter. When I had my K&N air filter in my car you could clearly hear more "sucking" of air into the air box during acceleration. Sometimes I could even hold the throttle and make it whistle for a while. I always knew it was time to clean the air filter when I couldn't hear that noise.

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^This^ Youtube intake whistle and a bunch videos come up with a similar noise. I've heard it in all my cars with an aftermarket intake or filter.

Lol am I the only one thinking how funny that you are worried about a "very concearning" engine noise but are still driving it around...If I heard a new noise and it bothered me I'd have someone more experienced than myself drive it and inspect it.

Definitely doesn't sound like intake whistle.

PghMiller said:

I know that the video makes it sound like an "air" noise, but in real life it sounds metal.
Like when I'm sitting idle and stick my head next to the air dam, it sounds like metal spinning real fast.

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I take it you mean your head was next to the air intake duct.
Air dam's are at the front of cars.

Is there anything in the engine compartment that is loose enough to vibrate.
What about one of the plenum plates coming loose?

I say normal intake sound. after I put the downforce air scoop inside the vent I noticed that same sound.

I say its normal but the gopro maybe making the sound different and sounding like air intake.

the only thing is vacuum leak.

hard to say.

how about take off the unifilter and put go pro in the engine bay near the intake and drive it again.

kertong said:

anything ever come of this? getting the same sound - in person it does sound higher pitched, and a unifilter made it way louder

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Why not switch back to an oem paper filter? I had a uni filter after I installed the ctsc and I do not care what dynos prove, I hated it. It was loud, obnoxious, and for a handfull of ponies I felt ZERO difference. Just saying, try a paper filter. The nsx is slow and a 50$ filter isnt going to change anything.

I watched the video 3X and can't seem to hear the noise your referring to. It sounds normal to me. Very interesting to see if it's anything.

[MENTION=12400]kertong[/MENTION], I think you worry too much.:smile: You have a downforce scoop right? They make tons of whoosh noises... If you do in fact have one, I have an oem scoop sitting in a box if you would like to have it to compare.