flutter when boosting

[idt512]

not sure if this is bov flutter or ignition related, but it happens right when i hit 15+ psi on a my 1G bov, im thinking either the bov is nearing the limit of what it can hold (18psi) and therefore it flutters as it cracks open (relieves pressure) then shuts (since the pressure is now lower after cracking open ) causing the flutter, my boost gauge looks steady though. My other suspicion is spark plugs or wires, the reason is about a year ago i steam cleaned my engine and water got down the spark plug holes and it was fluttering exact same way, i checked for water down the plug holes today but this time it was dry... So if someone can describe how BOV flutter feels like under WOT so i can somewhat compare what im experiencing and i can narrow down if its the bov or ignition.

 

[stirpicult]

not sure if this is bov flutter or ignition related, but it happens right when i hit 15+ psi on a my 1G bov, im thinking either the bov is nearing the limit of what it can hold (18psi) and therefore it flutters as it cracks open (relieves pressure) then shuts (since the pressure is now lower after cracking open ) causing the flutter, my boost gauge looks steady though. My other suspicion is spark plugs or wires, the reason is about a year ago i steam cleaned my engine and water got down the spark plug holes and it was fluttering exact same way, i checked for water down the plug holes today but this time it was dry... So if someone can describe how BOV flutter feels like under WOT so i can somewhat compare what im experiencing and i can narrow down if its the bov or ignition.

do you mean fluttering like, your boost gauge kinda bounces a little when you hit 15psi? your description is throwing me off, but my guess would be plugs and wires. my boost didnt like getting near 11psi (or whatever is stock) when i first got it. replacing the plugs and wires fixed that for me.

 

[ddavisaf]

If the car is bogging down (while drilving), it's a spark plug related problem. Regardless, your first step is a boost leak test.

 

[Maverick3169]

do you mean fluttering like, your boost gauge kinda bounces a little when you hit 15psi?QUOTE]
What would cause that?

 

[ddavisaf]

Boost leak usually.

 

[idt512]

my boost gauge looks steady though.

The car drives perfect until you go over 15 psi boost, but at 14 psi it has no flutter

Also i should mention that it flutters in 1st and 2nd gear a lot, 3rd gear has a slight hiccup, and 4th-5th has no flutter even when i boost 17 psi

 

[MyBeatGSX]

The BOV flutter noise that everyone talks about is compressor surge. It has nothing to do with the BOV making any noise, the noise is the air backing up and stalling the compressor and ocylating (sp?) between the intake manifold and compressor wheel.

But based on the fact that its gear dependant and your boost gauge is holding solid, I'd say surge isn't actually what its doing and you're discribing it wrong.

The gear dependant thing would seem to me like the opposite of compressor surge. It should be doing it in the high gears when it can't accelerate out from it, and not in the low gears when it can.

 

[stirpicult]

do you mean fluttering like, your boost gauge kinda bounces a little when you hit 15psi?QUOTE]
What would cause that?

mine did something similar to this, and i changed the plugs and wires and it was fixed.

 

[Maverick3169]

mine did something similar to this, and i changed the plugs and wires and it was fixed.

Are you talking about the actual needle of the gage vibrating or something? How would plugs and wires affect that? I just changed my plugs... my wires are magnacore 8.5's.