I have a custom catback exhaust so it might be what brings the sound out but when I am on half-load in first or second gear and lift off the gas, I hear what sounds the same as this http://www.youtube.com/watch?v=6GQtI...eature=related (the flutter sound right after the BOV vents. My mods are all the Alta Boost Tubes, Alta PnP ECU, Alta CAI, and Alta FMIC. I have read from the video that it could be possible that its a compressor surge. BTW I dont have an aftermarket BOV. Anyone have the same sound or know what can cause it?

 

Is it not just the OEM surge valve? It's audible with an aftermarket CAI which you have.

 

Ahh I was starting to worry because I hear compressor surge sounded just like that but then I realized I started hearing it after the exhaust so I wold guess it brought out the sound of it?

 

That's what I'd imagine, you should have noticed it with just the CAI installed also though?

 

I don't know what that video is supposed to show us?

That's just the sound of your stock bov/recirc valve...audible because of the CAI.

 

No compressor surge heard there on my end.

Wanna hear compressor surge?...Check this Vid out...Was previously posted somewhere on here,

 

Hmm... Mine sounds similar to that, Iv had the CAI for around 9k miles and just started hearing the fluttering sound when the bov vents after pvp ecu/ exhaust. Thanks for the fast replies oh and Jose its Rich from MoM (laser blue 07 ) =)

 

And sorry, that was the wrong video it looked the same, you can hear it in http://www.youtube.com/watch?v=9WYAxbVNTck . That fluttering sound is the same that I have. (Have to listen closely its like a flutter sound right after BOV venting.) Also, my car fluttering sounds similar to the one in the video.

 

Hey Rich, on that second video no Alta PNP right?

I heard something like it on the 2nd and 5th rev. It's not as obvious as the previous video I posted.

I had 2 problems with the PNP....It made the car stutter even after 3 different units...and would flutter with craziness. Ended up messing up the diaphragm of the wastegate/bov/air pressure releaser!!

 

When your call fluttered it happend while letting off on the gas? And whats the stutter problem you had? (wondering if I should take off the ECU and send it back again for reprogamming it to avoid possible damage.) Also what happend with the messing up of the diaphragm of the wastegate/bov/air pressure releaser?

 

Well I was pretty satisfied with the short bursts of power the PNP was giving...but lets say cruising at 40mph...the car would jolt like if I had just gotten rear ended. Would do it every couple of minutes or so. Pretty scary shizzle man.

Got all 3 types of harnesses with different tunes and no solution. (When switched back to stock no problems).

Yea the fluttering was happening when letting of the gas pedal...But would sound way way worse than yours.

 

Ouch does sound pretty scary. I dont have the problem with jolting just the fluttering which was getting my worried. Any opinions since you were a veteran of the problem? =P
A better video of how it sounds
http://www.youtube.com/watch?v=jEUWEsqoWz8
The Flutter part

Ill give Alta a call first thing tomorrow then. Thanks

Forgot to answer your question sorry, in the youtube video I posted I believe he did not have a PnP ECU. (Wasnt my car in the video)