Recently VVT Swapped my NA and have been battling this intake whistle at part throttle. It is present no matter the actual intake piping on the car. I've smoked tested and there are no leaks. Is it possible the IAC valve would cause this? It is currently closed all the way and was remote tuned around that set up so I haven't touched it.

Squaretop if that matters, no EGR and block off plates. Idles at 900rpm

Sound clip
https://whyp.it/tracks/203557/miata-...le?token=FnCfa

 

Nothing?

 

broken link. so nothing to go off of.

 

Reuploaded

https://whyp.it/tracks/205096/intake-whistle?token=Aww0j

 

Here is a photo
https://photos.app.goo.gl/Ss6jgRf2HBsSBMqg9

NB Throttle Body
Square Top
Stock PCV
Stock IACV (fully closed via screwdriver)
EGR Block off plates
Goodwin header
Short ram intake (intake length and piping doesn't change it)

 

Haven't responded, because I don't really have any ideas.

However, I am curious why your bypass screw is all the way closed? Maybe that's allowing that cavity to whistle? Have you tried backing it out ~5 turns and retesting? I've never gotten a car to idle with the screw all the way in, so there may be an intake leak you're missing too.

 

I asked my remote tuner and he said to not touch it as it would require a retune, thus I haven't messed with it. I wondered the same thing about a leak but nothing is showing up in a smoke test.

It's on an FM221 (me221) for what it is worth.

 

I still can't get the vid to load up.

 

Load it on youtube and copy link here.

Count the turns on the bypass screw. If it's truly all the way in, just back it off 5-6 turns, and see if it still whistles. When you're done with that test, put it back to where it was. All it'll do is cause a high idle.