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Turbo flutter

PostPosted: Sun Sep 11, 2011 8:52 pm
by wally09
Is this turbo flutter or bov sound?

I've got hyperflow cai, perrin turbo pipe, perrin tmic, and Perrin bov.

This is neutral reving. Ignore video just listen.
http://www.youtube.com/watch?v=RDAMfXeJzT0&feature=youtube_gdata_player

Re: Turbo flutter

PostPosted: Sun Sep 11, 2011 9:04 pm
by Jim
Yah just a tiny bit of flutter from what i can make out of the clip. Nothing to be worried about at all.

Re: Turbo flutter

PostPosted: Sun Sep 11, 2011 9:29 pm
by wally09
It's alot louder than that.

I went back to the factory bov to see if it helped
And then it threw an engine light :?

I think I just gotta tune the bov right. Trial and error I suppose

I want more wooosh than a, shhh tuu tu tu

Re: Turbo flutter

PostPosted: Sun Sep 11, 2011 10:00 pm
by Jim
A softer BOV will get what you want, but it will circulate air through at idle if its too soft which will make your ECU have to relearn. Like you said, just a matter of fine tuning.

Re: Turbo flutter

PostPosted: Sun Sep 11, 2011 10:15 pm
by Dropz
"woosh" is vented to atmosphere BOV. dont do it. it sounds wanky, and is illegal. But if you dont care for legalities and like the sound, go at it.

You have turbo flutter, which, whilst sounds good (IMO) is not ideal as it can damage the turbo.

Re: Turbo flutter

PostPosted: Sun Sep 11, 2011 10:38 pm
by wally09
Dropz wrote:"woosh" is vented to atmosphere BOV. dont do it. it sounds wanky, and is illegal. But if you dont care for legalities and like the sound, go at it.

You have turbo flutter, which, whilst sounds good (IMO) is not ideal as it can damage the turbo.



no i dont want atmospheric vent,, but when the intake is upgraded you can hear the vented bov blowing back into the intake pipe,,,

the perrin bov has an adjustment to change spring compression,, but im just not quite in the know how to get it right,,

any ideas on why it threw an engine light from putting the stock bov back on??????

note, the stock bov still has turbo flutter, just not as much,,, does this mean that the stock engines have turbo flutter? just putting this CAI on has unmasked the originally muffled and resonated stock sound?

Re: Turbo flutter

PostPosted: Sun Sep 11, 2011 10:58 pm
by Dropz
was it tuned at all with the aftermarket BOV? Factory one may operate out of the parameters if so, otherwise my guess would be something wasn't plumbed up right.

Re: Turbo flutter

PostPosted: Wed Sep 14, 2011 9:55 am
by Robbks
Dropz wrote:"woosh" is vented to atmosphere BOV. dont do it. it sounds wanky, and is illegal. But if you dont care for legalities and like the sound, go at it.

You have turbo flutter, which, whilst sounds good (IMO) is not ideal as it can damage the turbo.


My Auto Legacy made a huge "woosh" when you shut the throttle,
Through a fully-plumbed-back GFB Mach1 BOV,
it does have 35mm inlet/ outlet pipes on it to help move a heap of air.

Turbo damage from flutter is minimal (puts extra load on the bearings from the cavitation), i've seen turbo's run with no BOV's for 10's of 1000's of km's on high boost (24psi) day in and day out with no issues.
and then i've seen completely stock cars blow turbo's after 20-30k km for no apparent reason

Re: Turbo flutter

PostPosted: Wed Sep 14, 2011 7:05 pm
by Jim
Robbks wrote:
Dropz wrote:"woosh" is vented to atmosphere BOV. dont do it. it sounds wanky, and is illegal. But if you dont care for legalities and like the sound, go at it.

You have turbo flutter, which, whilst sounds good (IMO) is not ideal as it can damage the turbo.


My Auto Legacy made a huge "woosh" when you shut the throttle,
Through a fully-plumbed-back GFB Mach1 BOV,
it does have 35mm inlet/ outlet pipes on it to help move a heap of air.

Turbo damage from flutter is minimal (puts extra load on the bearings from the cavitation), i've seen turbo's run with no BOV's for 10's of 1000's of km's on high boost (24psi) day in and day out with no issues.
and then i've seen completely stock cars blow turbo's after 20-30k km for no apparent reason



BenTZ and VF8's comes to mind here :)

Re: Turbo flutter

PostPosted: Thu Sep 15, 2011 11:27 am
by cruisn
If you like flutter, adjust the spring in your BOV (if you can) to open only under higher boost.

Then the air will be circulated back through the turbo netting you flutter with daily driving.

I had a GFB on my Gen2 GT plumb 50/50. Driving to work through the city used to get annoying with the Pssssht every gear change. I preloaded the spring so that it only opened at 5psi and up so at normal driving in city traffic I would just get some flutter as the BOV wasnt opening.

Or you could just buy a VL. :lol:

Re: Turbo flutter

PostPosted: Sun Oct 16, 2011 3:25 pm
by cpitts
Agree on this. My car flutters and "pshhhh"'s as well with it's well opened up intake. Stock ECU, MT6.
Doesn't seem to take much to make it sound a little too ricey with this Subie setup (MY07 GT-B). Very obvious in S# mode of course. ;-)

Turbo flutter

PostPosted: Sun Oct 16, 2011 3:34 pm
by Gambit
For me it's all that plus an external wategate, you can imagine the stares I get in traffic !