happy new year all!

have some questions about "flutter"...

when i am at partial throttle, and let OFF the gas.. i get "flutter", consistently.

1. what is flutter? is this BOV flutter? Wastegate flutter?
2. is this common? do i have something wrong? i have stock IX MR BOV.. although i do have the Buschur BR330. (intake, downpipe, exhaust, test pipe, reflash)
3. is this "damaging" in any way?

did a search.. but didnt really come up with any solid explainations or fixes.

thanks in advance.

 

I dont drive an MR, nor consider myself an authority, but it sounds like possibly a stuck BOV. Most likely the flutter you hear is the backpressure on the turbine.

 

Search

 

Did you not read his post, "did a search.. but didnt really come up with any solid explainations or fixes", or did you just choose to ignore it? If you have an answer, post a link to the thread. Thanks and Happy New Year!

 

It is probably the bov fluttering and you can hear it because you have an intake.

 

yeah, BOV flutter it is. you hear it when you have the intake. if you have the stock intake box, you just don't hear but it is there. It is the bit of down side for owning turbo charged cars. you don't want to stay in partial throttle with the turbo. you eithter go fast or go slow. don't do medium.

 

Thats not really a realistic solution is it? I dont drive like its a playstation game where you have two throttle positions - on & off.

I'm going to guess that the BOV is either not seeing enough pressure to force it to pop off or that the spring is sticking the valve closed. Also, the original post asked about the possibility of damage due to turbine backpressure (flutter). While I dont have a link to any studies about this, I cant imagine that "back turbine" is good for the compressor. Can anyone else provide any info that is more conclusive?

 

One solution could be an adjustable BOV like the Forge RS. It has a knob to turn spring pressure up or down which controls when the boost is released (if I am explaining correctly?). So for you, you would set it at it sofest setting and adjust up till you start to hear/feel the flutter. I just set mine and it has almost eliminated the fluttering, but turbos don't like partial throttle I am noticing. BTW, it is louder than your JDM MR BOV. Another benefit is that it holds more boost pressure than the JDM or stock BOV.

 

My MR does the same thing. All I have is a 3" turbo-back. All else is stock. It'll flutter under very light throttle. I'm assuming it's normal. It's done it since I got the car a month ago.

 

It's normal.. The boost has to go somewhere when you let off the throttle, & the BOV does it, but when the pressure isn't enough to just blast through the BOV, it just sort-of flutters. I like it.

 

It's standard, especially with a strong BOV. Having an intake makes it louder. I don't ever hear any flutter with the stock box, but I"m sure it's happening, because I surge in high gears at part throttle whenever I mess up. By "mess up," I am referring to building partial boost then letting off slowly. That causes surge with a strong BOV, but if you just let off completely, it purges fine and doesn't surge. Just don't let off slowly...

 

ditto, normal

 

I get this when in lower rpms in 5th I start to press the throttle, get maybe 3-5psi and let off, this is usually below 3400rpm.
-James

 

there's partial throttle in gt3 and gt4

 

ive tried 4 different bov,s and the only one that ever completely eliminated surge in any gear was the 1g i got from buschur. ihad the upper intercooler pipe kit on my 03 8 and have the same one on my 06 BR350, It came with the upgraded forge and the surging was terrible, talked to dave buschur about it and told him the 1g worked great on my 03 and wanted to try it on the BR so he mailed me one right away and its great, absolutely zero surging idles like a dream and holds 20lbs of boost right to 7800 rpm,s which i did first time today, just past 1,000 miles, all broken in now fun fun fun