Whistle sound right before boost

F419sr1 · 06-10-2019, 07:32 PM

I installed a whipple on my Zl1 and had it tune at Jannetty’s. Made quite a few passes with no noise. Got it home put some miles on it with no issues. I got hard on it and right after I have a whistle. The sound isn’t all the time. It isn’t RPM consistent. It’s only right before boost starts and if I give it a little gas and goes into boost it goes away. If I hold the same throttle and boost drops into vaccine it comes back. Very low vacuum it isn’t there either. I checked all my hoses and sprayed around the hose ends and blower with Esther and nothing changed. It runs and idles fine. Performance wise nothing that I can tell has changed. I went as far as to pull the blower back off to see if any of the intake gaskets could have been damaged when I installed it and found nothing. I can’t reproduce it without load on it. Any ideas on the whistle noise.

D3adch1ld · 06-10-2019, 07:35 PM

Enjoy the jet engine noise. I have the factory 1.7L Eaton with a CAI and hear it too.

F419sr1 · 06-10-2019, 07:46 PM

Quote:

Originally Posted by D3adch1ld

Enjoy the jet engine noise. I have the factory 1.7L Eaton with a CAI and hear it too.

That’s not the noise I’m hearing. I know the difference. This is under vacuum right before it goes into boost and is a new sound.

HoldMyBeer · 06-10-2019, 10:47 PM

Quote:

Originally Posted by D3adch1ld

Enjoy the jet engine noise. I have the factory 1.7L Eaton with a CAI and hear it too.

+1

Same here with Roto-fab just coming into boost

BAD MOOOFOOO · 06-11-2019, 12:13 PM

Sounds like you're hearing sounds of the bypass partially closing before a transition from vacuum to boost. Like you're giving it moderate throttle but not enough to close the bypass all the way. You can probably recreate this in your driveway with one person playing with the gas pedal and the other filming with your hood popped.

Chris V · 06-11-2019, 12:50 PM

Quote:

Originally Posted by HoldMyBeer

+1

Same here with Roto-fab just coming into boost

Ditto. I can hold partial throttle and keep it whistling too. Whipple & Roto-fab.

BrotherxSpartan · 06-11-2019, 01:08 PM

What did you do with the OEM s/c?

F419sr1 · 06-11-2019, 03:03 PM

Quote:

Originally Posted by BAD MOOOFOOO

Sounds like you're hearing sounds of the bypass partially closing before a transition from vacuum to boost. Like you're giving it moderate throttle but not enough to close the bypass all the way. You can probably recreate this in your driveway with one person playing with the gas pedal and the other filming with your hood popped.

Here is a vid of the sound. I can’t get it to do it without a load on it.
https://youtu.be/6zy4EpN4Z-A

Boooost · 06-11-2019, 03:11 PM

Yea my whipple doesn't sound like that. Might hook a vacuum gauge up and see what kind of vacuum it's pulling at idle. Maybe a vacuum leak.

Alain · 06-11-2019, 04:06 PM

Quote:

Originally Posted by F419sr1

Here is a vid of the sound. I can’t get it to do it without a load on it.
https://youtu.be/6zy4EpN4Z-A

that sounds like an F350 turbo !

sorry you're having issued dude, hope you get it worked out.

On a brighter note, the exhaust sounds amazing. how big are the kook headers you went with?

F419sr1 · 06-11-2019, 04:35 PM

Quote:

Originally Posted by Alain

that sounds like an F350 turbo !

sorry you're having issued dude, hope you get it worked out.

On a brighter note, the exhaust sounds amazing. how big are the kook headers you went with?

Kooks 1 7/8. Made the video and did a short datalog and sent it to Ted. He says nothing to worry about. Sounds to him like throttle blade whistle. Said its common. I was concerned because i didnt hear it before and it was a new noise to me. Possible i just didnt hear it before.
better to check that find out later that its a problem.

Scottyz · 06-11-2019, 04:56 PM

Earlier when I read this I was going to respond that it could be the throttle blade. My brother had a 2004 GMC Envoy with the 5.3 LS engine. His made the same noise. No supercharger on his Envoy but did the exact same noise and I found it turned to to be the throttle body. I’ve heard a couple other vehicles with the same noise. All of them were drive by wire throttle bodies.

F419sr1 · 06-11-2019, 05:35 PM

Quote:

Originally Posted by Scottyz

Earlier when I read this I was going to respond that it could be the throttle blade. My brother had a 2004 GMC Envoy with the 5.3 LS engine. His made the same noise. No supercharger on his Envoy but did the exact same noise and I found it turned to to be the throttle body. I’ve heard a couple other vehicles with the same noise. All of them were drive by wire throttle bodies.

I was told Magnuson had the same problem and mad a angled spacer to address the problem.

F419sr1 · 06-11-2019, 10:50 PM

Quote:

Originally Posted by BrotherxSpartan

What did you do with the OEM s/c?

It’s on a shelve in the garage.

06-10-2019, 07:32 PM	#1
F419sr1 Drives: 2017 ZL1 Join Date: Jun 2018 Location: Randolph Posts: 317	Whistle sound right before boost I installed a whipple on my Zl1 and had it tune at Jannetty’s. Made quite a few passes with no noise. Got it home put some miles on it with no issues. I got hard on it and right after I have a whistle. The sound isn’t all the time. It isn’t RPM consistent. It’s only right before boost starts and if I give it a little gas and goes into boost it goes away. If I hold the same throttle and boost drops into vaccine it comes back. Very low vacuum it isn’t there either. I checked all my hoses and sprayed around the hose ends and blower with Esther and nothing changed. It runs and idles fine. Performance wise nothing that I can tell has changed. I went as far as to pull the blower back off to see if any of the intake gaskets could have been damaged when I installed it and found nothing. I can’t reproduce it without load on it. Any ideas on the whistle noise. __________________ Kooks full exhaust, Roto Fab, Whipple,Williams 103, Fore innovation, JRE cam and tuning Last edited by F419sr1; 06-13-2019 at 10:45 AM.

06-11-2019, 03:11 PM	#9
Boooost Drives: F1A TA Join Date: Dec 2018 Location: Raleigh, NC Posts: 6	Yea my whipple doesn't sound like that. Might hook a vacuum gauge up and see what kind of vacuum it's pulling at idle. Maybe a vacuum leak. __________________ 2017 ZL1 - Whipple, Cam 1997 WS6 F1a Procharged

06-10-2019, 07:35 PM	#2
D3adch1ld Drives: 2019 Camaro ZL1 1LE Join Date: Apr 2019 Location: New York Posts: 180 View My Garage	Enjoy the jet engine noise. I have the factory 1.7L Eaton with a CAI and hear it too.

06-11-2019, 12:13 PM	#5
BAD MOOOFOOO Drives: between cars Join Date: Apr 2019 Location: KC Posts: 52	Sounds like you're hearing sounds of the bypass partially closing before a transition from vacuum to boost. Like you're giving it moderate throttle but not enough to close the bypass all the way. You can probably recreate this in your driveway with one person playing with the gas pedal and the other filming with your hood popped.

06-11-2019, 01:08 PM	#7
BrotherxSpartan Drives: 2017 Camaro SS Join Date: Apr 2018 Location: St. Louis, MO Posts: 9	What did you do with the OEM s/c?

06-11-2019, 04:56 PM	#12
Scottyz 2019 ZL1 1LE MY GOON Drives: 1980 Z28 Big Red. Join Date: Dec 2018 Location: Stoney Creek Posts: 2,061	Earlier when I read this I was going to respond that it could be the throttle blade. My brother had a 2004 GMC Envoy with the 5.3 LS engine. His made the same noise. No supercharger on his Envoy but did the exact same noise and I found it turned to to be the throttle body. I’ve heard a couple other vehicles with the same noise. All of them were drive by wire throttle bodies.

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