CFar Posted August 12, 2005 Share Posted August 12, 2005 I did it, so far no ill effects but Im hearing something similar to wastegate flutter through the intake but since I dont have any other modification to the motor I cant hear it out of the exhaust. The noise can be best described as the sucking noise from the turbo, between 2-3000 rpm is pretty loud, and come 3500 the volume starts dwindling down to that fluttering noise, where at 4000 rpm the fluttering, and sucking noise from the turbo is completely gone. Though, when coming off throttle really hard, you still get the whoosh sound from the BPV. Those with aftermarket intakes, do you hear the flutter of the wastegate? Chris Link to comment Share on other sites More sharing options...
MDTURBO Posted August 12, 2005 Share Posted August 12, 2005 hard to tell since I have a DP, but I would imagine you would. 2012 Forester XT. Stage 2+ Retired from Racing. I used to build FMIC and more. Link to comment Share on other sites More sharing options...
Xenonk Posted August 12, 2005 Share Posted August 12, 2005 you'll hear more of the stock BOV than anything. The stock turbo uses an internal wastegate, and it gets muffled by the stock downpipe's cat. Keefe Keefe Link to comment Share on other sites More sharing options...
CFar Posted August 12, 2005 Author Share Posted August 12, 2005 I understand, but while on boost towards peak pressure (may be peak pressure as I dont have a boost guage) you can hear it almost fluttering. The sucking noise from the turbo that is. I am thinking/hoping thats what it is. The sound is very vague. It has a similar timing between "flaps" as the sound of wastegate flutter which leads me to believe thata what it is. Im hoping its not turbuelnce in there for what ever reason. Does anyone else have any input? Chris Link to comment Share on other sites More sharing options...
PhilT Posted August 12, 2005 Share Posted August 12, 2005 OK, just so I get this straight can someone explain the set up on the Legacy please. The boost pressure is controlled by 1) The BOV (or whatever it's called) recycling air back to the intake or 2) The exhaust wastegate opening and reducing the speed of the turbo. I've read about both, but know which is fitted, or are both ? TIA Double Award Winning Legacy GT Wagon Link to comment Share on other sites More sharing options...
MDTURBO Posted August 12, 2005 Share Posted August 12, 2005 boost level is controlled by the wastegate. Actually the built in boost controller controls the wastegate which controls max boost. lol. 2012 Forester XT. Stage 2+ Retired from Racing. I used to build FMIC and more. Link to comment Share on other sites More sharing options...
CFar Posted August 12, 2005 Author Share Posted August 12, 2005 Correct, BOV (or actually BPV) is for preventing surge back into the cold side of the turbo when you shut the throttle. It can be a bad thing, BUT, back to my question... What is up with the flutter? Chris Link to comment Share on other sites More sharing options...
rao Posted August 12, 2005 Share Posted August 12, 2005 This is how boost is controlled: http://www.legacygt.com/forums/showpost.php?p=153785&postcount=36 There should be no flutter unless the wastegate is loose (not all that likely although a lot of people seem to think theirs is) or you are at the stasis point so that the wastegate is opeinig and closing rapidly, which it will do given the right conditions. Rob IF YOU CARE ABOUT YOUR CAR YOU SHOULD NEVER DRIVE IT Link to comment Share on other sites More sharing options...
Xenonk Posted August 12, 2005 Share Posted August 12, 2005 Rao is right, there shouldnt be a flutter.. the waste gate controls a steady pace of air that the turbo is suppose to spin to generate a particular boost pressure. CFar, I think you are just trying too hard to listen for something that isnt really there.. typically, only external wastegates could be heard of this fluttering distinctively.. there isnt enough surges of exhuast gases for the stock internal wastegate to open and close at every pulse to create the flutter.. it all gets passed through the down pipe. Keefe Keefe Link to comment Share on other sites More sharing options...
CFar Posted August 12, 2005 Author Share Posted August 12, 2005 I recall having it in my WRX especially audible with the downpipe install. Whatever that sound is (what I was led to believe by possible rumor or not), is the same thing, only through the intake. Its at the threshold of boost, every time, very duplicateable. Does anyone who has the intake hear the same noise? If not wastegate flutter, similar/connected to the sound after a downpipe install. Link to comment Share on other sites More sharing options...
Xenonk Posted August 12, 2005 Share Posted August 12, 2005 It should sound more like a steady leak than a flutter.. I use to have a Blitz SUS Power Intake and you can hear EVERYTHING that goes on.. and fluttering was not one of them. It's possible that the the STOCK BOV is just being a pansy and it's opening too soon for the pressure and it gets recirculated into the intake track again and thus creates an additional "slapping" of the two air flows, but even that is not much to pinpoint since it's a complete pressurized system. Keefe Keefe Link to comment Share on other sites More sharing options...
CFar Posted August 12, 2005 Author Share Posted August 12, 2005 Hmm, I wouldnt say Im too worried about it, just confused as to what it may be. It may possibly be turbulence? I dont know, maybe my BPV is being a pansy ninny waste ha. Its vague but detectable so hopefully nothing is wrong and power doesnt seem to be too effected but I need to road test more. please feel free to respond to my questions though if you have any info. Thanks though everyone, Chris Link to comment Share on other sites More sharing options...
CFar Posted August 12, 2005 Author Share Posted August 12, 2005 With a more lengthy test ride power actually is noticeable, but obviously nothing drastic. But back to the noise, it can be best described as the sucking noise from the turbo, between 2-3000 rpm is pretty loud, and come 3500 the volume starts dwindling down to that fluttering noise, where at 4000 rpm the fluttering, and sucking noise from the turbo is completely gone. Any new ideas anyone? Chris Link to comment Share on other sites More sharing options...
Xenonk Posted August 12, 2005 Share Posted August 12, 2005 nope, I still dont get that from my WRX nor my GT as I can recall. Keefe Keefe Link to comment Share on other sites More sharing options...
rossodave Posted August 13, 2005 Share Posted August 13, 2005 I got the same noise when I had the perrin short ram on my car. My best guess is that its the stock BPV. It must be very weak. Dave Link to comment Share on other sites More sharing options...
mattg Posted October 4, 2005 Share Posted October 4, 2005 Now that i have a Perrin drop in filter, i can hear my factory BPV distinctly. It sounds like it leaks a bit from the onset of boost until ~ 4K rpm where it goes silent, until I shift. Is it be normal for the BPV to leak a little bit? Seems like it would be counterproductive to making maximum power. Link to comment Share on other sites More sharing options...
CFar Posted October 4, 2005 Author Share Posted October 4, 2005 exactly same with mine. Very pronounced and its a solid sound up until 3k, where it becomes more of a flutter, then at 4k, it is silent. Sounds the same as a wastegate flutter on a stock WRX, only hearing it through the intake instead. I wonder if anyone will be able to figure it out Link to comment Share on other sites More sharing options...
firedawgs Posted October 4, 2005 Share Posted October 4, 2005 I have the AVO boost actuactor. No waste gate flutter now. Updated my vBGarage: Link to comment Share on other sites More sharing options...
S0CalGT Posted October 5, 2005 Share Posted October 5, 2005 I have the Blitz SUS filter and have been experiencing the same noise since I've installed it. Never thought much of it because I've never felt a drop in performance or heard other "strange" engine noises... by the way, I'm getting my car tuned on Friday at PDX Tuning with the 1.5T package! Off topic, but I'm just too giddy about it! -Fred Link to comment Share on other sites More sharing options...
VXCL Posted October 5, 2005 Share Posted October 5, 2005 angry crickets= wastegate flutter MAYHEM #122/22 STS NNJR SCCA AUTOX4U.COM XENON RETRO GUIDE Link to comment Share on other sites More sharing options...
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