Questions regarding compressor surge

[hugador]

Also, like stated before you will not get rid of that flutter noise completely. You shall hear it at low rpms when you let go of the throttle and when you gun it at high rpms there should be that whatever your bov should sound like after letting go of the throttle.

 

[hugador]

Thanks, I was watching my LTFTs today and I get a postive 14 while just cruising or going WOT. That was with my stock bov and cobb intake.

14 is a bit high but I hear you get high numbers from other members with a Cobb intake. So I don't know if 14 is okay.

 

[AZMS3]

Today I talked with the previous owner of the bov and he said it is normal for it to make the flutter sound when it releases boost. He said that it did the same on his Speed6.
While having the greddy bov my car seemed to run good. No issues at idle, or stumbling, or cel. It was only the flutter sound it releases that had me worried. I have turned the screw 4 full turns soft and got the flutter still. I went back to normal and did 4 full turns hard and got the same flutter. I don't know if Im not adjusting correctly or if greddy bov at rec. makes the flutter.
Thanks for everyones input.

 

[AZMS3]

14 is a bit high but I hear you get high numbers from other members with a Cobb intake. So I don't know if 14 is okay.

Thats weird Cobbs intake causes such high LTFTs, since it has air straightner. Do any over intakes such as a cold air run with lower LTFTs?

 

[hugador]

Today I talked with the previous owner of the bov and he said it is normal for it to make the flutter sound when it releases boost. He said that it did the same on his Speed6.
While having the greddy bov my car seemed to run good. No issues at idle, or stumbling, or cel. It was only the flutter sound it releases that had me worried. I have turned the screw 4 full turns soft and got the flutter still. I went back to normal and did 4 full turns hard and got the same flutter. I don't know if Im not adjusting correctly or if greddy bov at rec. makes the flutter.
Thanks for everyones input.

So you're all set then haha. The flutter noise gets people nervous as I did but after some research it's normal. Other turbo cars get them too like Subaru and srt4.

 

[hugador]

Thats weird Cobbs intake causes such high LTFTs, since it has air straightner. Do any over intakes such as a cold air run with lower LTFTs?

Other reason I say Cobb intake gives high numbers is becuse you're stock tune. And stock numbers are 3.6 to 5.5 at idle and 8 under acceleration. Don't know about CAI but on a stock tune with my CPE intake LTFT numbers did not change from stock. Thats why a maf tune is required becuse every intake is a bit different.

 

[Little Beavis]

In my sig is a recording I did long ago, one channel is a mic on the back bumper, the other channel is under the hood. No compressor surge, but obviously a different car. I would recommend that you loosen it up as much as possible without causing any driveability issues or fuel trim issues.

I have a BOV on my 2010 speed 3 and that one is all the way out too. . .no flutter or turkey, just venting noise. . .and no driveability issues. If your car stumbles or such, then bring it back in, but the purpose is obviously to vent the air and prevent fluttering aka surge.

 

[Saskatchewan17]

Simply put... the type S shouldn't cause any flutter... at least at our boost pressure. The valve isn't opening correctly. In my pic is where the threads were stipped and the bolt was super soft and loose... I had to re-tap it. There really shouldn't be any flutter with any valve that you have. Some will flutter a little in low boost and vac... but after 5psi or so there really shouldn't be any. Flutter is where the turbo is being spun backwards. And that is hell on a turbo.

 

[AZMS3]

Simply put... the type S shouldn't cause any flutter... at least at our boost pressure. The valve isn't opening correctly. In my pic is where the threads were stipped and the bolt was super soft and loose... I had to re-tap it. There really shouldn't be any flutter with any valve that you have. Some will flutter a little in low boost and vac... but after 5psi or so there really shouldn't be any. Flutter is where the turbo is being spun backwards. And that is hell on a turbo.

Tonight i finally took apart the type S and found what the problem had been.
The previous owner had put an extra nut inside the bovs screw to keep it at a tighter setting. Also the screw was stripped inside the bov, and it would not loosen. Once I fixed the screw and took the extra nut out, everything was ok. Now my car pulls great, huge difference over the plastic stock piece. No more flutter. Its a little louder than stock and will chirp at times under WOT.

Thanks for all the help

 

[rmgedon69]

Tonight i finally took apart the type S and found what the problem had been.
The previous owner had put an extra nut inside the bovs screw to keep it at a tighter setting. Also the screw was stripped inside the bov, and it would not loosen. Once I fixed the screw and took the extra nut out, everything was ok. Now my car pulls great, huge difference over the plastic stock piece. No more flutter. Its a little louder than stock and will chirp at times under WOT.

Thanks for all the help

usually when it flutters, the bov or bpv adjustment is too tight. not familiar w/ greddy bov but it usually is the culprit (fluttering).

glad you got that figured out.