blow off valve - vent to atmosphere mod (increase sound)

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diego d

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Can someone please give me a step by step on how to do this mod. I just installed an air aid intake and it wasn't much louder then stock. Although i appreciate the increased air flow, i want to be able to hear the turbos more.


Thank you so much!
 

jman1200

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Mine came with that mod, could not "hear the turbos more", just a "pwewww..." when it vented.
I reversed that mod as I noticed that over time, the area where it was venting was getting all dirty and oily from the fumes.
 

fordfanstan

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After I completed the VTA BoV mod I barely noticed any louder blow off sounds. However, over time I feel like the sounds have increased and I am happy with the temporary mod.
 

SM105K

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I have a boomba bov on my Focus ST and it is fun. Would I want one on my SHO? No. My VTA BOV's on my SHO are good enough.
 

diego d

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any downside to the VTA BOV mod? Has anyone had any issues with it after a long period of time?? Also, what is the trick to getting the one at the back (harder to get to) done.
 

SM105K

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any downside to the VTA BOV mod? Has anyone had any issues with it after a long period of time?? Also, what is the trick to getting the one at the back (harder to get to) done.

No, no, and watch the video. I shows you everything you need and they did it in a parking lot.
 
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skyshadow07

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No downsides? What about possible over spinning of the turbos? Or increased spool up time. As well, you would be running rich (even accounting for open-loop full throttle) because the ECU expects that air to come back into the system.
I was surprised to see this mode on this forum. Evolution guys were divided down the middle about it. That's a younger buyer though. The only pro is sound.
 

15SHOPP

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It will not effect the AFR or ECU due to our cars being MAP not MAF. It will not increase spool time nor over spin the turbos. The turbos already spool super quick due to their tiny size.
 

SM105K

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Both will be louder, one will be quieter. You can do one, both, or none. The choice is up to you.
 

jman1200

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I first reversed the front one and that took care of about 85% of the "pweew" so my guess is that the front one is noisier. Reverted the back one about 6 months later.
As said, downside is getting oil vapor sprayed in the engine bay. Won't see it right away but it will eventually leave a spot.
 

skyshadow07

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It will not effect the AFR or ECU due to our cars being MAP not MAF. It will not increase spool time nor over spin the turbos. The turbos already spool super quick due to their tiny size.

Even MAP systems will go open loop under full throttle.
Aside from you saying so, why would the turbos not have the over spool risk. You stated they spin up quick because they are small. You have a sudden volume or pressure drop on one side (compressor) of a turbo and a constant pressure on the other side (turbine), the turbo will spin faster.
A turbo size is not the only factor in spool up time. turbine and compressor pressure, air volume, flow pulse.. a lot goes into it.

The bottom line is the ONLY advantage is you get an early 2000's type BOV sound. Being that the possible risks are not factually dismissed but more of an opinion or educated guess.. why risk it at all?
This is the same crowd doing annual complete fluids flushes but is onboard with this mod. I'm so confused.
 

diego d

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Even MAP systems will go open loop under full throttle.
Aside from you saying so, why would the turbos not have the over spool risk. You stated they spin up quick because they are small. You have a sudden volume or pressure drop on one side (compressor) of a turbo and a constant pressure on the other side (turbine), the turbo will spin faster.
A turbo size is not the only factor in spool up time. turbine and compressor pressure, air volume, flow pulse.. a lot goes into it.

The bottom line is the ONLY advantage is you get an early 2000's type BOV sound. Being that the possible risks are not factually dismissed but more of an opinion or educated guess.. why risk it at all?
This is the same crowd doing annual complete fluids flushes but is onboard with this mod. I'm so confused.

so would you suggest getting a BOV adaptor instead?
 

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