got bored today, so i decided to do a lil OEM intake box modification:

1. cut out that baffle piece on the inside
2. cut a hole on the end of the box to put a 3" alum pipe and routed that to the airhole behind the headlight

well...after that, the sound is different...its much more pronounced. the throttle response is better too.

BUT...now there is this humming noise that is coming out of the intake tube. its weird...if you take off the filter and put your ear to that pipe, you can hear a humming noise.

anyone ever experience anything like this before?

 

Every intake has its own distinctive sound and harmonics. You just changed the way the airbox controls this sound. This should come as no surprise to you.

 

its not from the harmonics of the airbox, cause if you take the intake out of the box, it still makes the sound.

it seems to be coming from the two holes that are in the throttle body to keep the car from dying when idiling. i have checked all the hoses to this, and everything looks good. if i put a finger on the bottom hole in the TB, the humming is reduced to normal....

what to do?

 

I didn't say it's from the harmonics of the airbox. When I say "intake", this includes everything from the first instance air goes into the car to the throttle body to the intake manifold. Those holes in the TB, as you say, has to do with the Idle Air Control and is part of what makes an S2000 tick. Those "normal" and naturally occuring sounds are altered, amplified ( or whatever) by the nature of the equipment that is attached to what makes it. You changed that.
I'm not sure what you are trying to get at in your post. Are you concerned that something is wrong? Are you annoyed at the new sound it's making? Are you trying to find ways to "fix" it even though nothing is broken? I'm just a little confused.

 

as soon as the altered box was put it, there was no noise. after about 10 mins of driving...i opened the hood to make sure everything was ok...and about 30 seconds later, the humming started. if i had an unmodifed airbox on the car, the humming will still be there.

guess its not a very common problem.

has anyone had this humming noise? its constant now.

and i am just trying to get a solution for this problem, i guess you've never had this humming noise before.

 

I'm no expert, but I think they all hum if you modify the air box or remove the air box cover. Every Honda I have owned since my Del Sol made this sound when the stock box was fooled with.

I used to own muscle cars a long time ago. If I removed the air cleaner lid, the carburetor would make a LOUD sucking noise. I guess this is simular.

 

I have a CAI and I get the humming. This is normal and not a problem.

 

The humming noise is the idle control valve. Get someone to turn on the high beam and you will hear the hum change as it bleeds more air past the throttle body.

Speedracer

 

when i had the AEM V1 CAI it did that humming noise, perfectly normal..
As for the reason x-viper nailed it..
sounds really cool if you ask me!!

 

but....if i put the stock airbox on, it still makes the humming noise....is there just no way to get the sound to go away?