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Discussion Starter · #1 ·
Well from my profile I am sure all you folks out there can see that I am a noob. So please excuse my ignorance if it is so. I recently put a Blitz FMIC on my car. For now I am still running the stock turbo, that will change soon though. Now for the reason that I am posting about this again. I disconnected the FMIC and put my stocker back on because I was looking at about a month and a half before I could get in for a dyno tune at Turbo XS. Well they called me yesterday to tell me that they had an opening for Saturday. So of course I took it. So today I put the FMIC back on in preparation for my Sat tune. The first time that the FMIC was installed the car ran like crap afterwards, it had no power, and really not a lot of pull and it had a rough idle. I posted about that and was told to get the dyno tune, so when I put it on this evening the car is running completely different, no rough idle...it has a lot of pull again, it is running nothing like it did last time, however something is unusual now. From the intake when ever I let off the gas, the intake makes a noise like it is spitting out air?? This is really hard for me to describe, if I give it a little throttle, it is subtle, if I give it a lot, you really hear it, it sounds like the BOV except it make's a slightly different sound of purging air about 5 or 6 different spurts one after another. Please excuse the long winded story, I felt as though I needed to fully explain everything. If you have any ideas please let know. If this is normal then you can call me a jackass, and tell that it is supposed to do that. Thanks a lot.
 

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My Blitz SUS only makes a sucking sound when the boost gauge reads about zero (when the turbo is spooling up). I don't see why it would be making a sound when you are letting off the throttle.

I don't have a FMIC, but could the sound you are hearing be the BOV, as it has been moved to the front of the car near the intake?
 

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Discussion Starter · #3 ·
The BOV is about 2 inches or so from the throtltle body. I am positive that it is not the BOV, because the BOV will purge when the boost gets high enough, and you still will hear the intake noise seperatly. the both make similar noises, however they have different pitches. I am thinking that it is possibly the air in the pipes that I am hearing, but I am not sure, I think that the car will be good till I can get to Turbo XS on Saturday. Hopefully they will be able to better pin point what it is. thanks for the help.
 

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locam said:
The BOV is about 2 inches or so from the throtltle body. I am positive that it is not the BOV, because the BOV will purge when the boost gets high enough, and you still will hear the intake noise seperatly. the both make similar noises, however they have different pitches. I am thinking that it is possibly the air in the pipes that I am hearing, but I am not sure, I think that the car will be good till I can get to Turbo XS on Saturday. Hopefully they will be able to better pin point what it is. thanks for the help.

don't you mean the wastegate? but what you just described about the boost purge is what a wastegate does not a BOV
 

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Sort of. Depending on the BOV, it will begin to leak air at a certain PSI. That is why they make different springs and shims for them...

locam, just to clarify, you are hearing the noise when on the gas, or getting off the gas?

VV

EvilCerealBoX said:
don't you mean the wastegate? but what you just described about the boost purge is what a wastegate does not a BOV
 

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Discussion Starter · #6 ·
I hear the noise when I get off the gas. Depending on how much throttle I give it, sometimes the BOV will prrge the air and the intake will also make the noise. However I always have the intake noise when I get off the gas. If I give it a lot of throttle then the intake noise is much louder, less throttle and the noise is more subtle.
 

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Are you running the stock BOV or a recirc BOV? If so, it sounds to me like you are just hearing the BOV. A recirc (like the stocker) is plumbed back into the intake...so it will push air there.

VV
 

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Discussion Starter · #8 ·
I am running a 100% atmospheric, the plumb back portion is actually blocked off now. The plug for the plumb back portion was actually provided with the FMIC kit. I wish that I had a program so that I could go in and adjust the size of my pics, that way I could post them here to let you all see it. If anyone can tell what program to use maybee I can get some pics posted.

caelin~
 

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Here is an excellent lightweight, FREE program:

http://www.irfanview.com/

VV

locam said:
I am running a 100% atmospheric, the plumb back portion is actually blocked off now. The plug for the plumb back portion was actually provided with the FMIC kit. I wish that I had a program so that I could go in and adjust the size of my pics, that way I could post them here to let you all see it. If anyone can tell what program to use maybee I can get some pics posted.

caelin~
 

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Discussion Starter · #10 ·
ok lets see if this works now. Hopefully I will be able to show you all the location of the BOV. Sorry for the crappy pic, but that is the best that I can do. From this you shoule be able to see the pluged plumb back portion. VV: thanks for the great program, and all the help so far.

caelin~
 

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after I put my FMIC on, I was getting MAJOR wastegate flutter from my turbo. I had a 100% atm bov on, and that thing would blow off only when under boost. so when i was hitting 12-13lbs, i would get BOV noise and major "WA WA WA WA WA" sounds. (like loudly whispering that phrase). put the stock BOV on, no more flutter, now i got the APS FMIC BOV, and it's running great. just a thought for your head.
 

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Discussion Starter · #12 ·
So after putting a plumb back portion on your BOV you were able to get rid of the noise?
 

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I had that same problem when I ran a Blitz BOV. I switched to the combo recirc/atmos vent valve that GFB puts out and that totally solved the problem for me. I think that sound you're hearing is something like kickback that the BOV won't catch b/c it's only venting to the atmosphere. If you get a combo recirc valve, it should take care of the problem by putting that air to better use.
 

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Discussion Starter · #14 ·
ok I will keep that in mind. I will look to see if I can get the same brand and also have ir recirculate.
 

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flutter?

What you seem to be describing is the fluttering of the wategate at low rpm/no boost throttle release which becomes much more prevalent with the SUS .I would bet that is what you're hearing since it comes from the vicinity of the filter and can deceive you into thinking its coming from the intake. Shouldn't hurt a thing.
 

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i never heard my flutter with the SUS until after i put my FM on. my car basically drove like crap until I put a recirc/atm combo BOV on.
 

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hmmm?

I do not have the FMIC but I did put a 100% vta blow off valve on at the same time (Forge) as the SUS,and I too hear the fluttering on such off throttle. It may be the plumbing aspects of the bov or some other phenomenon which occurs once you start changing things around but it only seems to be coming from your intake because of the proximity to it I believe.I know this is of no help to you about why it happens but I hope it eases your mind about it not hurting anything if that is truly what you are hearing.
 
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