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Posted

Hello All, 

I got my truck back from the shop after having the supercharger put on and when I totally pin the throttle I hear a loud squealing noise from mid cabin.  The supercharger whine is awesome but gets drowned out by the squeal under full throttle. I had a truck before make that noise when the exhaust I put on was not clamped down right. It made me think of the flapper valve in the GM Borla exhaust I have and was wondering if that could be it. Its in the same area I hear the noise? The tune took off the cylinder deactivation so I no longer need the flapper. Any suggestions on the flapper? I was going to tack weld it open but wasn't sure if that would stop the noise and also thought about cutting out that piece of pipe and welding in a new piece. 

Any suggestions?

 

I know [mention=118595]1SLOW1500[/mention] has dealt with several modded trucks. What do you think? 

 

 

 

 

 

 

 

 

  • Like 1
Posted

Yes you need that removed. I would guess the higher exhaust flow is causing the flapper to open and exhaust to escape. I would not recommend pinning it open in any way. As exhaust build up under truck and possibly in to cabin through rear cabin wall vents or rear window. Cant 100% promise that's it but the turbo trucks and one local whipple truck had to do that.

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Posted
5 minutes ago, 1SLOW1500 said:

Yes you need that removed. I would guess the higher exhaust flow is causing the flapper to open and exhaust to escape. I would not recommend pinning it open in any way. As exhaust build up under truck and possibly in to cabin through rear cabin wall vents or rear window. Cant 100% promise that's it but the turbo trucks and one local whipple truck had to do that.

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Ok great. Ill have it cut out and a new piece welded in or buy a new exhaust. Tacking it open would have the same affect as cutting it out wouldn't it? 

Do you hear the squeal in the first video? I know the whine is normal and appreciated but the high squeal doesn't sound right. I've never had a Supercharged vehicle so I don't know.

Posted

What exhaust do you have? I ask because there is a out of the norm option that may be better for you.
The diesel exhaust if I remember right it much larger and it bolts in other then the connection to the y pipes but that's a easy job for any shop.

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Posted
37 minutes ago, 1SLOW1500 said:

What exhaust do you have? I ask because there is a out of the norm option that may be better for you.
The diesel exhaust if I remember right it much larger and it bolts in other then the connection to the y pipes but that's a easy job for any shop.

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I have the GM Borla side exit exhaust. I can get that flapper section cut out and rewelded with a slick piece or tack the spring open. WOuld there be a disadvantage to tacking it open rather than having it cut out? I like the exhaust and how it sounds/looks Id like to keep it if I could. 

Posted
I have the GM Borla side exit exhaust. I can get that flapper section cut out and rewelded with a slick piece or tack the spring open. WOuld there be a disadvantage to tacking it open rather than having it cut out? I like the exhaust and how it sounds/looks Id like to keep it if I could. 
Bang for the buck and if you.like the sound rotate the square counterclockwise then fish a piece of safety wire through the corner cut outs and through the matching corner cut outs and twist wire tight. See how you like it. Turbos are a little quieter so we run the largest exhaust that flows the max. But superchargers aren't much different so more open the better but sound has to match the performance.
Performance wise remove it but again see it noise goes away with it just open first.

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  • Like 1
Posted

Getting it cut out as we speak and a piece of slick pipe welded in.


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  • Like 1
Posted
On 3/22/2019 at 2:50 PM, 1SLOW1500 said:

Bang for the buck and if you.like the sound rotate the square counterclockwise then fish a piece of safety wire through the corner cut outs and through the matching corner cut outs and twist wire tight. See how you like it. Turbos are a little quieter so we run the largest exhaust that flows the max. But superchargers aren't much different so more open the better but sound has to match the performance.
Performance wise remove it but again see it noise goes away with it just open first.

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Had that piece deleted and still makes the noise under full throttle. Took off the tips and closed the hole on the muffler where the condensations drain is and the noise hasn't changed. My only thought is because it has dual tips out the muffler. Ill have to change the whole exhaust to get rid of it most likely. Don't know if it will bother me that much and don't know if that's it 100% or its supposed to be that way. I digress. 

Posted

Is there are muffler and a resonator? And what size is the pipe?
I have to think it is restriction based.
Options are custom and larger catback
Diesel catback. Think that is 3.5 or even 4".
Or electric cut out. Can donut manual or boost actived and set to say 2/3 of the max boost so it's open before rpms aren't to high.
Hard to answer this for you as it is personal option on sound.
But again inhale to think that exhaust was never build with your power and air flow in mind.


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Posted
2 hours ago, 1SLOW1500 said:

Is there are muffler and a resonator? And what size is the pipe?
I have to think it is restriction based.
Options are custom and larger catback
Diesel catback. Think that is 3.5 or even 4".
Or electric cut out. Can donut manual or boost actived and set to say 2/3 of the max boost so it's open before rpms aren't to high.
Hard to answer this for you as it is personal option on sound.
But again inhale to think that exhaust was never build with your power and air flow in mind.


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Its has a 2.5" single pipe into a muffler and then duals out into (2) 2" pipes. I'm thinking it has to be the split making the noise. If I go true dual with 2" all the way back with not that aggressive mufflers that might solve it but it'll be louder than Id want it I bet. Cant have both lol, first world problems I guess :)

Posted

That is really small. I know my limit is right in the over kill. But I would want 3.5-4".
Even on my 3.5 i had so much back pressure i blew out the inserts and the rear pipe off.
I would want 3 at the exhaust headers then that size all the way back and if it merges the new number not smaller so dual 2.5 is still in my option 4". Also for muffler no chambered muffler. These means possibly more mufflers but they do not hurt the flow at all.

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  • Like 1
  • 2 years later...
Posted
On 3/22/2019 at 4:20 AM, Denali34 said:

 

 

 


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did you ever find out what the noise was as this is also present in my set up but with corsa exhaust

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