Turbo flutter / cavitation / wastegate chatter - Is it bad?

[h100vw]

Looks good to me.
Venting the boost to atmosphere is a personal thing, not for me though. Removing the DV altogether would be pointless and slow down the turbo between changes.

I would be willing to bet that early turbo applications from the 70s didn't have DVs and this would make the lag they experienced much worse.

There was a post on audi-sport.net the other day saying that not having a DV would not harm the turbo.

Gavin

[Jmac]

Yeah Gav correct mate, 930 Porsche turbo with the Kjet had no divertor, and it kicked in around 3800-4000rpm and it was something else, not for the faint hearted and then try and stop it Yeah Scirocco and Mk1 comes very much to mind!!!!!!!!!!!!!!!!!!!!
Jmac

[Petrina Polo]

I think some people on here are confusing the flutter or compressor surge with a bov expression of air..

whether you use a duel port bov (vent in intake and atmosphere) or just vent into the intake, the idea of the upgraded DV is to hold the boost properly in chipped cars. The OEM DV valve may leak under higher boost. Im not sure at what point it will leak. Maybe not at all but its just a cheap way to make sure your not leaking boost.

On my car with a POD filter, the APR DV can be heard expressing air when backing off the throttle in a shhhhh!! type of noise.. This is air being chucked from after the turbo to before the turbo.. This would be more predominant using a duel port bov. This is completely different to compressor surge.

This is confused with the rattlesnake sound heard when the air is not expressed using a DV. It bounces around now that the throttle body is losed, bouncing back on the turbo blades creating that sound. As many have said purely for posers and no benefit to performance, arguably a detriment.

[Blitzen]

I have had the Forge BOV for well over 12 months now, and have never had the flutter sound with the various setting I have tried...Must just be me...

[Tim]

http://www.youtube.com/watch?v=HS4cyOxLtMs&feature=related

[noone]

Thanks Polo GTI Boy, thats diagram is on my level!

I'm not convinced the flutter is as bad as it could potentially be, but really don't want to risk it...

Blitzen, I had the dial wound the full way closed, found that when I backed off after the turbo had spooled (3000 rpm) and back off, the flutter would occur most easily (in 2nd for example).

Well, Think I'll let the diverter do what it was designed for and dial that puppy right back...

Thanks for everyone who chimed in.

[Kai]

http://www.youtube.com/watch?v=HS4cy...eature=related

Good old VL's. hahaha.

[Ben_GTI]

http://www.youtube.com/watch?v=HS4cy...eature=related

fully sick ulea!!

[Chipped]

There is no performance benifit at all. Its purely for "Wank factor"

Well said Blow off Valve is what it says "Blow off"