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Old Apr 20, 2011 | 11:38 AM
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Strange Air Sound At High RPM

I was driving home yesterday and decided to push it a bit seeing that there was an open road ahead of a few cars.

I down shifted to 4th and was revving at about 5k-5200 rpm and staying there waiting to take off.

While I was in that rpm range, it sound like the strangest air sound to do with the boost.

I still have the stock BPV on...with a GST 93 + boost pill tune.

I'm guessing it must be the BPV. Are they really THAT leaky that it sounds kind of messed up when being pushed.
Old Apr 20, 2011 | 11:42 AM
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I don't get it. When you say "and staying there waiting to take off" were you brake boosting? If not then you were not in boost so................................................ .................................................. .................................................. ..........................
Old Apr 20, 2011 | 11:56 AM
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Sorry...what I meant, I was driving on the highway. I was behind a few cars waiting for them to move over. Ahead of them was open road.

So while waiting for them to move over, I downshifted from 6th down to 4th and the revs were at about 5k-5200k and I held the throttle there for a bit.

It was a weird sound. Like an air noise. I assume it was the stock BPV...
Old Apr 20, 2011 | 01:48 PM
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I doubt the stock BPV would leak at 5000, but it very well could be. Did it sound like air being sucked in or blowing out?
Old Apr 21, 2011 | 06:14 AM
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Originally Posted by Jasoob
Sorry...what I meant, I was driving on the highway. I was behind a few cars waiting for them to move over. Ahead of them was open road.

So while waiting for them to move over, I downshifted from 6th down to 4th and the revs were at about 5k-5200k and I held the throttle there for a bit.

It was a weird sound. Like an air noise. I assume it was the stock BPV...
It's not going to "leak" if you not under boost plain and simple since there is no pressure to leak. I think you were just hearing the lack of insulation and the noisy little 4 banger under the hood. For what it's worth, the pitch of the engine changes dramatically at 3,500 rpm.... one of the thing I love about the RA is the tall 6th geat so I can cruise at 80mph and stay under the 3,500 rpm cross over.
Old Apr 22, 2011 | 05:55 AM
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I kind of like the sound when it gets to higher RPM..haha!

Well, it sounded just like air being sucked in randomly or something. Sort of hard to explain. It was definitely the BPV though.

Next week I'll have the Synapse Enginnering one on so I'll do a test, no more weird air sound, then I guess the stock BPV was the culprit.
Old Apr 22, 2011 | 05:56 AM
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I know that a lot of people have said the stock plastic BPV isn't very good so it's probably safe to say it's related to it somehow. And it was definitely boosting...
Old Apr 22, 2011 | 12:53 PM
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I did it again today. The best way I can describe it, it sounds like a bird chirping that's dying. Like an inconsistent high pitched whistle/ait chirp sound.
Old Apr 22, 2011 | 02:05 PM
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I have the ams/evo x bpv on mine, when i get on the gas above 3000rpm specially in manual mode i can hear air wistlin... i assume it air being drawn in thru the intake,least i hope it is... better not be a leak lol
Old Apr 22, 2011 | 08:25 PM
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Mine was doing the same...check your licp...that was leaking for me..use a flashlight rather than poul the bumper though at first...check all couplers etc...one may have split or something and making a noise?

Last edited by hixlancer; Apr 22, 2011 at 08:26 PM. Reason: Spelling correction damn phone
Old Apr 22, 2011 | 09:01 PM
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Thankd for the heads upp give me something to do tomorrow
Old Apr 22, 2011 | 09:04 PM
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hey no prob! You'll need a flashlight...look down below the battery area...its a tight fit and you can see with a flashlight if that clamp is gone etc...mine has blown off twice now..switching to T-clamps to solve that issue shortly.
Old Apr 22, 2011 | 09:15 PM
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mine is the same... AMS/EVO BPV but its just like an high air suckin in or soemthing idk...
i also installed my Boost Gauge today and my idle is at -10. so i am guessing fosure i have a leak somewhere.. =[
Old Apr 23, 2011 | 06:51 AM
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Originally Posted by Cesarn2928
i also installed my Boost Gauge today and my idle is at -10. so i am guessing fosure i have a leak somewhere.. =[
Not necessarily. I think it's normal for a boost gauge to show negative pressure on our cars when simply idleing.
Old Apr 23, 2011 | 09:44 AM
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+1 at idle the turbo isn't developing any positive pressure, so -10 should be fine. I just checked my recent datalogs, and at idle the OEM sensors are showing similar readings -8 at idle for my car...


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