Stock Air Intake Resonator....What's It Really There For?

[Rich]

I have wondered about this for awhile. I have two stock intake tubes, one from an 05 without a resonator and one from an 07 with the resonator. From what little I could find online they are used to cancel sound waves reverberating from inside the intake manifold and could potentially add a little power due to smoother airflow? I can buy the sound wave canceling theory, but not the power adder theory.



Anybody got any real information on these things?

 

[Deathstang II]

huh...that's interesting didn't know anything about this. My guess is to just quiet the engine than actually add any real power. And lets be real, no one driving a V8 want's to be quiet.

 

[Rich]

And lets be real, no one driving a V8 want's to be quiet.

Agreed...I did find an article that talked about how these silencers can cause a power loss if removed, but I sincerely doubt that. I'm just wondering why some model years have them and some do not...I mean, what's the point?

Here's a segment of the article that talked about wave reversion:
"Adding an expansion chamber to the intake tube forces air coming back out of the engine to slow down to fill the cavity, thus expending a great deal of its energy and slowing the pressure wave reversion. This slowdown allows fresh air to flow toward the engine without fighting pressure reversion waves the entire way, thus aiding in cylinder filling. Since these pressure waves are essentially sound, giving them a place to expend their energy before exiting the air filter box ends up dampening the intake noise and quieting the engine. Thus, the resonator helps to make the engine paradoxically quieter and more powerful."

 

[Midlife Crises]

The only real thing it does is alter the frequency. Then someone came up with the bright idea of a sound tube to pipe the intake noise into the cockpit. I mean come on, really!

 

[Rich]

Yeah, that sound tube into the firewall seems pointless. The Shelby GT's used the stock intake tube with the Steeda CAI filter and heat shield instead of using Steeda's intake elbow. I'm wondering if there was any power lost, however minimal, by doing that. Looking into the stock intake tube reveals how it "steps down" an inch or so at that ribbed portion. I wonder if that ribbed portion, combined with the air resonator causes any serious air flow problems.

 

[Iceman62]

My wife wishes they'd make a resonator f/ my A$$...so farts aren't so loud.

JK, I believe this is Ford's way of recycling plastic to save it fm being added to landfills.

 

[Juice]

Its called a Helmholtz resonator.

 

[Rich]

My wife wishes they'd make a resonator f/ my A$$...so farts aren't so loud.

Hahaha, ditto on that for me too...especially after eating spicy food.

Its called a Helmholtz resonator.

Yeah, I found that out last night after doing some more research. Appreciate the info though!

 

[LarryJM]

I deleted the sound tube and it makes it much easer to hit the rev limiter in second.

 

[Rich]

Are you talking about the resonator I mentioned earlier or the tube running to the firewall on the 2010+ models?

 

[Deathstang II]

Eh....I'd just put a CAI, plate delete, tune and be done with it if the engine is so worried about power loss. That'd be an easy fix right there.

 

[Juice]

I have tested CAI vs stock airbox and could not tell any difference.

 

[LarryJM]

Never good to use underhood air for intake air.

 

[Forty61]

Agreed...I did find an article that talked about how these silencers can cause a power loss if removed, but I sincerely doubt that. I'm just wondering why some model years have them and some do not...I mean, what's the point?

Here's a segment of the article that talked about wave reversion:
"Adding an expansion chamber to the intake tube forces air coming back out of the engine to slow down to fill the cavity, thus expending a great deal of its energy and slowing the pressure wave reversion. This slowdown allows fresh air to flow toward the engine without fighting pressure reversion waves the entire way, thus aiding in cylinder filling. Since these pressure waves are essentially sound, giving them a place to expend their energy before exiting the air filter box ends up dampening the intake noise and quieting the engine. Thus, the resonator helps to make the engine paradoxically quieter and more powerful."

Weird. I would have guessed if it was to catch air coming back out of the intake tract that the box would be closer to the throttle body.. I’m also surprised though that there’s enough air coming back out of the intake to warrant it. I learned something today!

 

[Juice]

Weird. I would have guessed if it was to catch air coming back out of the intake tract that the box would be closer to the throttle body.. I’m also surprised though that there’s enough air coming back out of the intake to warrant it. I learned something today!

It isnt air coming back, it is soundwaves that cause a little restriction to airflow. It started appearing as OEMs keep looking for smaller and smaller gains to help with fuel economy and performance.
Nothing like the old days of large round air cleaners sucking hot underhood air!

 

[LarryJM]

Never good to use underhood air for intake air.

You do get active intake temps via the temp gauge from the radio. The intake air and outside air should be exactly the same.

 

[Rich]

Has anyone ver had the stock intake tube setup with the FRPP (Steeda) CAI? Anyone with a Shelby GT use anything different than this stock setup?

 

[Hawgman]

The '05 intake had them "built in" instead of external and hanging off the side of the intake tube. Was a thick disc with a honeycomb of paper in it (if I remember correctly). Removed mine about 30 minutes after I drove home from the dealership.

 

[Juice]

The '05 intake had them "built in" instead of external and hanging off the side of the intake tube. Was a thick disc with a honeycomb of paper in it (if I remember correctly). Removed mine about 30 minutes after I drove home from the dealership.

And probably gained nothing at all except some noise.

 

[Forty61]

And probably gained nothing at all except some noise.

I mean, I could name a few mods I’ve done in past that we’re purely for noise. That’s half the fun!