well i meant flutter or that booooossstttt noise that u get from no bov or a shitty one at high boast, which i thought was compressor surge. Man that sounds terrible, running too high boost or what causes that?

sounds like my mates R2D2

Surge is the situation when the compressor "spits out" more air than the engine can swallow, which causes a backup of air at the intake and it actually creates reverse-flowing pressure waves that can be very damaging to the turbo. You want to avoid surge at all costs......

This is Garrets Surge explanation:

"The surge region, located on the left-hand side of the compressor map (known as the surge line), is an area of flow instability typically caused by compressor inducer stall. The turbo should be sized so that the engine does not operate in the surge range. When turbochargers operate in surge for long periods of time, bearing failures may occur. When referencing a compressor map, the surge line is the line bordering the islands on their far left side.
Compressor surge is when the air pressure after the compressor is actually higher than what the compressor itself can physically maintain. This condition causes the airflow in the compressor wheel to back up, build pressure, and sometimes stall. In cases of extreme surge, the thrust bearings of the turbo can be destroyed, and will sometimes even lead to mechanical failure of the compressor wheel itself.

Common conditions that result in compressor surge on turbocharger gasoline engines are:
A compressor bypass valve is not integrated into the intake plumbing between the compressor outlet and throttle body
The outlet plumbing for the bypass valve is too small or restrictive
The turbo is too big for the application"

The reverse pressure waves/ inducer stall cause the chirps you can hear in that vid.

It's airflow related not boost pressure related.

It only happens on full noise under certain conditions but it is bad!

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this happens when i dont have my foot down hard enough sometimes when running over a bar, does everyones do that? it goes away with alittle more throttle. but its nothing like the video like a minor version of it?

can I have a gander some time?

Low boost flutter is nothing to worry about.

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i thought any turbo did low boost flutter with the bov tightened right up? my gfb hybrid flutters with my vf37 if i say spool it up to 10psi and get off the gas

is 15 psi concidered low boost? LOL
if i take my foot right off the gas pedal it usually always opens the bov
the low boost flutter happens when u just take ur foot off abit to get off boost.

yeah pretty much.

with a cai or pod the sound gets amplified

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[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

Your getting part throttle surge.

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[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]