I recently installed a SRI intake for my 3.0 and i hear a loud UFO noise (while throttle is at idle and under 1.5 K RPM. I can only assume that the pipe itself is vibrating to a harmonic resonance and makes the thing amplify the sound.

Otherwise, the little noise from the intake is resonating in the (resonator) and it is freaking loud.

In the upcoming days i will try to fix this problem and keep you guys posted.

(it also seems to resonate in my garage as well. I pulled it into my friend's garage overnight (after a few too many drinks) and it wasn't nearly as loud...)

I will try
Blocking the resonator (trumpet portion)
Removing the resonator

Modifying the intake.

 

If you cut the tube to remove the bend it should take care of it (from what I've heard). I don't have that problem with mine fortunately.

 

Just take out the resonator man, you don't need it. That is what I did and it's just about oem quiet at idle. No loud hum, no UFO.

 

Take out the whole resonator

 

Yep, take out the resonator. It's just taking up space needlessly.

 

same exact thing happened to me and i took out the resonator and it was gone.

 

welcome ? lol. try the resognator thing.. how bout some

 

With the paper plugging


the plugging helped a bit, quieted the thing down a little but it was still pretty darn loud. So I went on to step two the resonator removal.



(installed with the resonator removed.)
this was just as loud as before any modifications at all.

So i took it over to a friend who owns a speed shop for some advice. He removed the filter and put a towel across the intake. No Hum whatsoever. put the filter back on and there it is again.

i figured making a fin to go around the bend in the pipe would fix the vibrations... it went well and just about halved the decibels but there was still a hummmmmmm.

All I can think of now is to get a K&N with a 30 degree angle and lop off nearly half the bend and continue it with the filter. That would reduce the turbulence going around that corner.

 

is the hum really all that annoying for you to go through all this trouble? I wouldn't have any experience on that since im a 2.3 and never had that issue

 

Now that I think of it, there is a SLIGHT hum but now where near as loud as what I think yours sounds like. Looks like the same intake too. Looks pretty low tho. Sounds pretty good to me.

 

try straightening out the intake pipe itself (where it connects to the throttle body). thats usually the cause of the ufo noise.

 

Mine hums pretty loud. My gf said she can hear it from inside her house when I pick her up.

 

Ytse has the idea... I have been told i can be heard down the block... My UFO going on a probing run.

Update:

It was exactly what i thought. the harmonic resonance because of the length and shape of the tube made it so that it had reacted to the fundamental frequency of the air traveling through the filter.
this made it freaking loud!

i shaved the tube down about a half of an inch from both ends and the sound was reduced drastically.

I removed the bend completely like doubleshot suggested and it worked like a charm.

I am making a cold air box next i made a template as long as my intake was off and submitted it to a friend who will fab it up for free. It should be done today.

Just because im thorough... I borrowed the local college's decibel meter.

Horn (for reference): 108db

Stock intake: 73db

SRI Humming: 91db

Resonator with paper: 85db

No resonator 90db

Straight Pipe 75db


I couldn't get the fin tested before I had to give the meter back but i would guess it helped around 2-5 db


Those of you with 3.0s who haven't had this problem did you have a no-name filter or say a K&N?

Side note: Recommended spark plugs anyone?

 

I use a no name (BOMZ Racing) intake and air filter. I do have a K&N air filter tho. I still gotta try it on. But I have a slight hum (what you would expect with a aftermarket intake which is kinda the point) but nothing you can hear "down the block" as some of you say, or UFO, whatever that sounds like.

 

I cut my intake's elbow off and now there is no hum