[Sledgehammer70]

I have posted in a few forum threads on this topic as that is where this discussion began, but I felt this potential issue is one to merit its own thread. The problem is pretty clear. A whistle type noise is heard when installing some aftermarket cold air intakes.

At first, many members of the forum were quick to blame the aftermarket cold air intake. But after some testing, it is very clear the sound is generated from the throttle body and the intake manifold. The guys at Cold Air Inductions were able to set their car up to highlight this here.

I had not seen other final retail aftermarket cold air intakes until yesterday when I installed my Mishimoto CAI. Knowing my Cold Air Inductions did make the noise (but muffled with my ported throttle body), I wanted to see if the materials within the design of the Mishimoto offering would hide the whistle noise a bit better like the GM stock intake.

Well here are the results:



To boil it down... this isn't a whistle generated by the cold air intakes. This so-called sound is a product of the blade on the throttle body when it is open at roughly 25-28%. The internal suction from the motor creates an odd sound leading to the 'whistle' noise people have mentioned.

Now that I have tested the Mishimoto offering and the Cold Air Inductions offering and found the same results... a 'whistle' at a certain throttle range. Someone is going to have to create a heavier CAI with materials that dampen the sound from the throttle body and intake manifold or craft something that fixes the issue altogether at the heart of the source. Possibly a new throttle body, or thinner blade or adjustments to the intake manifold.

Overall the issue doesn't bother me much, but it seems to bother a lot of other people here.

[SuperSound]

Going to be interesting to see if the GM CAI is the same or if they did something with the design to mitigate it.

[Roto-fab 1]

It’s great to see unbiased reviews on aftermarket intake systems. We hope you will take the time to do the same with our CAI upon it’s release!

To speak to the whistle noise that has been created or enhanced by some aftermarket air intake systems:

I have driven a car equipped with a competing aftermarket CAI. After familiarizing myself with the problem, I was able to reproduce and sustain the sound for a few seconds. I then tested the Roto-fab intake with the sound enhancing tube and with our sound enhancer delete kit. I can confidently say that at any RPM range, in any gear, at any throttle position, the Roto-fab air intake system does not produce or enhance any undesirable noises!

[IMG][/IMG]
Roto-fab air intake system with sound enhancing tube, Please note that the components do not have the texture finish that the production system will feature.


Roto-fab intake with pre-production elbow & sound enhancer delete kit

Thanks again for your valuable reviews!
Michael

[jamminj007]

I thought there was an exhaust issue now when I read the title, but thank God it is the intake still. I have gotten used to mine and now I really don't even notice it.

I am glad to hear that rotofab is apparently the only one that doesn't whistle. Now to decide if it is worth purchasing theirs over CAI.

[Sledgehammer70]

Going to need to buy a Roto Fab intake as well and test it out

My growing List...

- Stock GM Intake
- Cold Air Inductions Intake
- Mishimoto Intake

Need to buy...
- Roto Fab Intake
- AFE Intake
- GM Performance Intake

[asimpleguy]

Originally Posted by Sledgehammer70

Going to need to buy a Roto Fab intake as well and test it out

My growing List...

- Stock GM Intake
- Cold Air Inductions Intake
- Mishimoto Intake

Need to buy...
- Roto Fab Intake
- AFE Intake
- GM Performance Intake

Sledgehammer, have you noticed any sound difference between Mishimoto and CAI when installed on your car? I'm referring to the depth of the growl the intake will enhance when compared to stock. Thanks

[horizon670]

Interesting !

Cold Air Inductions has a Video on YouTube showing that the Whistle is actually coming from inside the factory Intake Manifold !

[D2enigma]

I just installed mine by Cold Air Induction and I did notice this whistle sound. First I thought that it was actually the sound of air sucking in so I thought it was pretty cool, but at the same time, I wanted to make sure that this is not a problem. From what I'm reading, this is not something I should worry about as long as I'm not annoyed by it, right?

[Lakeshow]

I just installed the mishimoto air intake and noticed the "whistling" sound as well. Glad you made this thread as I was thinking maybe something wasn't tighten correctly. It's definitely noticeable but I'm sure I'll learn to live with it.

I hear it around 2500-3000k rpm and 4000-5000k rpm.

[Sledgehammer70]

Originally Posted by asimpleguy

Sledgehammer, have you noticed any sound difference between Mishimoto and CAI when installed on your car? I'm referring to the depth of the growl the intake will enhance when compared to stock. Thanks

The Mishimoto has a deeper tone to it from what my ears are hearing.The Mishimoto also seems like it is taking a deeper breathe (if that makes sense). Both have the same feel across gears and RPM ranges.

[Sales @ CAI Inc]

Originally Posted by Sledgehammer70

I have posted in a few forum threads on this topic as that is where this discussion began, but I felt this potential issue is one to merit its own thread. The problem is pretty clear. A whistle type noise is heard when installing some aftermarket cold air intakes.

At first, many members of the forum were quick to blame the aftermarket cold air intake. But after some testing, it is very clear the sound is generated from the throttle body and the intake manifold. The guys at Cold Air Inductions were able to set their car up to highlight this here.

I had not seen other final retail aftermarket cold air intakes until yesterday when I installed my Mishimoto CAI. Knowing my Cold Air Inductions did make the noise (but muffled with my ported throttle body), I wanted to see if the materials within the design of the Mishimoto offering would hide the whistle noise a bit better like the GM stock intake.

Well here are the results:



To boil it down... this isn't a whistle generated by the cold air intakes. This so-called sound is a product of the blade on the throttle body when it is open at roughly 25-28%. The internal suction from the motor creates an odd sound leading to the 'whistle' noise people have mentioned.

Now that I have tested the Mishimoto offering and the Cold Air Inductions offering and found the same results... a 'whistle' at a certain throttle range. Someone is going to have to create a heavier CAI with materials that dampen the sound from the throttle body and intake manifold or craft something that fixes the issue altogether at the heart of the source. Possibly a new throttle body, or thinner blade or adjustments to the intake manifold.

Overall the issue doesn't bother me much, but it seems to bother a lot of other people here.

Thank You Sledgehammer70 for providing additional validation that the "whistle noise" is NOT caused by our aftermarket air intake system. You do a great job of providing information to other Camaro enthusiasts.

[D2enigma]

So, this is not something that will damage the car in any way, correct?

[SuperSound]

Originally Posted by D2enigma

So, this is not something that will damage the car in any way, correct?

Correct, since it is present in the stock setup, undoubtedly there is something in the TB/manifold design that produces the whistle. The stock airbox was probably specifically designed to mask the whistle.

[enzia35]

Think the ported TB will remove the whistle?