[BLKZL12021]

I have a 2021 zl1 that I just bought. I recently installed a rotofab cold air intake about 500 miles ago. Started getting this weird whistle sound when I hit the gas in low rpm’s (around 2k) and goes away higher in the band. I have read about this problem along with NPP valve rattle. Was wondering if people who had similar issues could post a clip so I could compare the sound I am experiencing. Going to swap out the rotofab to the stock unit today to see if it’s the intake but any feedback is appreciated

[BLKZL12021]

Quick update… I was browsing other threads and my noise sounds exactly like the one below. Is this the rotofab? If so what did anyone who had this problem do to fix it?

https://youtu.be/6zy4EpN4Z-A

[BlaqWhole]

The 2 sounds are blower whine and the whistle that air makes as it passes thru an air filter. Typically with an open element underhood style intake you'll hear air whistle as it gets pulled thru the filter. You'll hear that even on NA cars. That is normal. Blower whine is likewise normal. On a Hellcat blower whine is extremely loud, like a siren. On the ZL1 it is not as noticeable but still there. Both sounds are normal and again increase when opening up the intake or exhaust side of things.

[BlaqWhole]

Oh and a lot of times whistle diminishes the more you open the throttle (step on the gas). At slight throttle you'll hear it...partial throttle will be less, half or full or higher in the RPMs might be even less or nonexistent. It's all good tho and is a sign of a normal healthy good running engine.

[BLKZL12021]

Originally Posted by BlaqWhole

The 2 sounds are blower whine and the whistle that air makes as it passes thru an air filter. Typically with an open element underhood style intake you'll hear air whistle as it gets pulled thru the filter. You'll hear that even on NA cars. That is normal. Blower whine is likewise normal. On a Hellcat blower whine is extremely loud, like a siren. On the ZL1 it is not as noticeable but still there. Both sounds are normal and again increase when opening up the intake or exhaust side of things.

This makes me rethink the rotofab then. I didn’t have this sound before and it’s pretty annoying. I love the sound of the blower wine but this just makes me think something is wrong with the car. There is nothing that can be done to fix this?

[BlaqWhole]

Originally Posted by BLKZL12021

This makes me rethink the rotofab then. I didn’t have this sound before and it’s pretty annoying. I love the sound of the blower wine but this just makes me think something is wrong with the car. There is nothing that can be done to fix this?

It is normal and there is no way to fix it unless you swap out for a boxed style intake or go back to your original stock intake. I think CAI makes a system for our cars these days and it is boxed. You might still hear it but it won't be as noticeable.

[Camaro1973]

Originally Posted by BLKZL12021

Quick update… I was browsing other threads and my noise sounds exactly like the one below. Is this the rotofab? If so what did anyone who had this problem do to fix it?

https://youtu.be/6zy4EpN4Z-A

No that’s not normal. And I can guarantee the fitting around the throttle body is loose.

Re-check and tighten back down all connections from The Roto fab.

I can duplicate this sound everytime if I loosen the clamp around the throttle body.

What’s happening is your sucking in air through a tiny gap , hence whistling sound. Fix it and it will go away.

[Camaro1973]

Originally Posted by BlaqWhole

It is normal and there is no way to fix it unless you swap out for a boxed style intake or go back to your original stock intake. I think CAI makes a system for our cars these days and it is boxed. You might still hear it but it won't be as noticeable.

Not normal bud. Shouldn’t be any high pitched whistling coming from the intake.

[BlaqWhole]

Originally Posted by Camaro1973

Not normal bud. Shouldn’t be any high pitched whistling coming from the intake.

All of my cars have that whistle at slight throttle. I even manipulate the throttle just to hear it because I like it that much. It sounds completely normal to me.

My ZL1 after all the mods no longer has it. But if I was back home then I could do a video of my Hellcat and GT and manipulate the throttle so you can hear it.

However I could be wrong. So perhaps OP should try reinstalling his intake to see if that solves the issue. I doubt it tho.

[radz28]

That whistle could just be air going past the throttle blade. I've had that happen with a couple cars. If that's the case, it's nothing to worry about. I'd still check all your connections, though, because if you DO have a leak, it's not going to be picked-up by the MAF (unless you're trying to run SD), and you could have issues.

I doubt it's much to worry about if you make the checks, though. Those are the kind of sounds you can expect to find when you start modifying.

[BLKZL12021]

Originally Posted by radz28

That whistle could just be air going past the throttle blade. I've had that happen with a couple cars. If that's the case, it's nothing to worry about. I'd still check all your connections, though, because if you DO have a leak, it's not going to be picked-up by the MAF (unless you're trying to run SD), and you could have issues.

I doubt it's much to worry about if you make the checks, though. Those are the kind of sounds you can expect to find when you start modifying.

I checked all the connections. Everything looks secure and tight. I wasn't concerned about it being an actual issue with the car. More of an annoyance factor.

[radz28]

I can tell you that moving from the OEM-air box increased noise (which I didn't mind at all). I can tell you that moving from that standard RF to the BG increased noise even more. I know that's not what you're posting about (moving from the RF to BG), but it sounds like what you're hearing is normal, in your case.

If you're annoyed, you might see about ported TBs. I haven't really seen many comments regarding what you're talking about, but, as you likely saw, there are many contours within the TB-mouth. I wonder if an aftermarket (ported even) TB might help. I'm, specifically, thinking about a ported OEM 87mm (or even an upgraded ported LT5, if you're thinking about mod'ing) from Soler, for example. Among many other enhancements, they reprofile the blade, which I wonder if it would help in your case. If you're annoyed enough, maybe reach out to them to see if they have any comments/experience with sound enhancements with their ported products. Even if you're worried about your warranty, you could pop an aftermarket/ported TB right off if you need to go to the dealer. I knife-edged my blade (among some other changes) and don't get any whistle that I can hear. I've changed the dynamics of my engine a bit because of the blower, so that might account for some of that, too, though.

Those comments are all within the logic of only your annoyance factor. I wouldn't necessarily recommend spending money on my suggestions if you were planning on mod'ing in the future. The likely fact is, until you increase the exhaust noise from your car (to mask the intake noise), the intake noise is going to be loud, and increase some with mods'. If you're only worried about the intake noise, you might consider just reinstalling the OEM-intake. There are some tests showing your RF increases power, but there are others that show, that, apparently, the ECM relearns and starts pulling the increase in torque from the RF (aftermarket intake) until it's making OEM-type-torque, so you ultimately get no performance benefit.

You might already know about a lot of that, but in case you didn't, you have some of my thoughts and experience.

[Camaro1973]

Originally Posted by BLKZL12021

I checked all the connections. Everything looks secure and tight. I wasn't concerned about it being an actual issue with the car. More of an annoyance factor.

You shouldn't have a high pitched whistle. In that you tube video that is loud. That can easily be reproduced by fittings not connected tight or on all the way. If i loosen my clamp around my TB mine will whistle like that.



You should only really hear a Shhhhhhhhh type of sound.

[est1979]

quick question - is that the dry filter or the wet one?