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Pillager's alter ego!
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Discussion Starter · #1 ·
I got the Synapse BOV and installed it this weekend but I think it is causing compressor surge. I've gone through all the threads on that but I'm still not sure. It's installed as directed using the same connection the stock BPV uses. I also have the block off plate on the stock BPV location. I've checked the connections and even swapped the vacuum hoses. Any ideas? I also installed the AEM digital boost gauge and it reads -6hg while powered on with the engine off. It also reads this way with the vacuum/boost connection disconnected. At idle it reads -22 to -24hg. The video below is of the noise I'm getting. I filmed it while backing down the driveway and back up. Only seems to happen when I'm not WOT. At WOT everything seems fine.

 

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hmmm, very interesting indeed.
 

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Sounds like BOV flutter to me, which does no harm IMO. I just have a hard time believing a synchronic does that. Do you have a BOP or are you using the CBV? Or does synapse make an adaptor for the BOV to fit on the compressor? Though if it is happening while not WOT, I am assuming you are using the RCV as well? Which synapse claims their BOV is "fast enough" to use, this shows different.

And it seems your boost gauge has a -6 bias in it if when the enging is off it reads 6inhg and 24. Not realy a problem, if you are aware of this. But I would try to get a new one if I could with a warranty.
 

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Pillager's alter ego!
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Discussion Starter · #4 ·
Sounds like BOV flutter to me, which does no harm IMO. I just have a hard time believing a synchronic does that. Do you have a BOP or are you using the CBV? Or does synapse make an adaptor for the BOV to fit on the compressor? Though if it is happening while not WOT, I am assuming you are using the RCV as well? Which synapse claims their BOV is "fast enough" to use, this shows different.

And it seems your boost gauge has a -6 bias in it if when the enging is off it reads 6inhg and 24. Not realy a problem, if you are aware of this. But I would try to get a new one if I could with a warranty.
It comes with a block off plate to go on the turbo where the stock BPV is. I have that installed. The Synapse is fitted onto the elbow on the cold side just before the throttle body. I'm not sure what the RCV is so let me know and I can hopefully answer that. The video clip below is of me driving. You can hear the noise just as I let off the gas and before the BOV opens. It seems pretty quick, not as long as it was in the driveway. You can hear the turbo spool, then the noise (lower pitch) then the BOV open (higher pitch). Still think it's flutter? I should note the sound is definitely coming from the turbo area. The Synapse BOV is on the cold side of the IC so it's on the other side of the engine.

 

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RCV is the solendoid to the right of the BCS when looking at from the front of the car.

I am running off the IM, as when I was hooked up to the RCV, mine did that.

Though since synapse is easy to see the valve, watch it when you hear the noise. If you see it fluttering/pulsating, then it is BOV flutter. If not, then it is most likely compresor surge, which I am doubting.

When you idle rev, the vac isn't as strong and most likely has issues going through the RCV to the BOV. So when you drive go WOT under load it doesn't flutter as the vacuum is stronger.
 

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that's obviously compressor surge, easy to hear the intake muffle it a bit. my car runs that exact same BOV off ECU signal through the OEM BOV solenoid, no issues.

if you're using a manual boost controller you may be messing with the ECU's feedback data and causing this to happen. if you've tweaked your wastegate arm to amp up boost, that's also a potential cause.
 

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Pillager's alter ego!
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Discussion Starter · #8 ·
are you using a manual boost controller? Dynojet CMD or PA Flash?
No. Stock boost controller. Same port that the stock BPV is hooked up to. No CMD or flash.

RCV is the solendoid to the right of the BCS when looking at from the front of the car.

I am running off the IM, as when I was hooked up to the RCV, mine did that.

Though since synapse is easy to see the valve, watch it when you hear the noise. If you see it fluttering/pulsating, then it is BOV flutter. If not, then it is most likely compresor surge, which I am doubting.

When you idle rev, the vac isn't as strong and most likely has issues going through the RCV to the BOV. So when you drive go WOT under load it doesn't flutter as the vacuum is stronger.
I have it installed the same way ScoobahSteve did his. Same as the install directions. I'm pretty sure it is coming from the compressor side as the BOV is on the other side of the engine.

ScoobahSteve's pics:
http://www.gencoupe.com/2-0t/45507-review-synapse-synchronic-bov-kit.html
 

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Pillager's alter ego!
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Discussion Starter · #9 ·
that's obviously compressor surge, easy to hear the intake muffle it a bit. my car runs that exact same BOV off ECU signal through the OEM BOV solenoid, no issues.

if you're using a manual boost controller you may be messing with the ECU's feedback data and causing this to happen. if you've tweaked your wastegate arm to amp up boost, that's also a potential cause.
I have not messed with the wastegate at all either. Would it be a problem with the stock boost controller solenoid?
 

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well no I don't think so. only other possible cause if you have a vacuum leak on your lines, and/or one of the O-rings inside the BOV isn't seated properly after mounting to the flange.

at this point I'm inclined to also think your stock boost control solenoid may be going buggy, which has happened to a couple cars (also with their other solenoid, the BCS) but it's not common by any means.
 

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Pillager's alter ego!
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Discussion Starter · #11 ·
well no I don't think so. only other possible cause if you have a vacuum leak on your lines, and/or one of the O-rings inside the BOV isn't seated properly after mounting to the flange.

at this point I'm inclined to also think your stock boost control solenoid may be going buggy, which has happened to a couple cars (also with their other solenoid, the BCS) but it's not common by any means.
I'll check the o-ring on the flange. If it were loose, wouldn't I get some pressure leak right there that I could hear? Maybe I'll put the camera right on that spot and see if I can hear anything.

I do want to get the Grimmspeed EBCS at some point but I need a flash to utilize that right? Or could I put it on there to test? Maybe I can get one of the other coupes here in the area to let me try their stock boost controller and see what happens.
 

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Well, beign that WM has that bov, I would listen to him over me, but I just don't hear any cmopressor surge. I think is more pnumatic than mechanical sounding though you hear it more from teh intake side in taht vid. Again, a easy way to tell is look at the bov opening. It it oscillates when the noise happens, it is the bov valve fluttering.
 

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Pillager's alter ego!
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Discussion Starter · #14 ·
I took all the Synapse stuff off tonight and put the stock back on. I checked the o-ring in the synapse where it connects to the elbow and that looked ok. Before I did though I got a vid of the Synapse. You can't hear the surge real well because it's coming from the other side of the engine. It almost seems like the Synapse is just a fraction of a second too slow. Once it does open it seems ok but I'm getting that surge before it does.



Below are the vids of the stock setup after I put it back.

stock BOV backing down the driveway and back up:

driving with the stock BOV:

It does not sound like the compressor surge is there so that would mean everything stock is ok, including the stock boost controller right? So my next step I think is going to be to give the guys at Synapse a call and see what they think. Any input is appreciated.
 
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It does not sound like the compressor surge is there so that would mean everything stock is ok, including the stock boost controller right? So my next step I think is going to be to give the guys at Synapse a call and see what they think. Any input is appreciated.
Stock setup is perfectly fine and your stock boost controller is fine.
I'm sure a call to Synapse wouldn't hurt.
 

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I got a chance to watch your vids. It is hard without being there, but the vid that shows your BOV opening, I don't hear any surge or flutter. But it looks like it is responding quickly, and if it is open, it can't be surging. So I don't think you were able to dupilcate those conditions to get the surge/flutter in that video.
 

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Pillager's alter ego!
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Discussion Starter · #17 ·
I got a chance to watch your vids. It is hard without being there, but the vid that shows your BOV opening, I don't hear any surge or flutter. But it looks like it is responding quickly, and if it is open, it can't be surging. So I don't think you were able to dupilcate those conditions to get the surge/flutter in that video.
It does open, just when not under WOT it is a bit slow. The surge happens before it opens in those conditions. You can't hear it in that last video because my camera is on the other side of the engine and it is not the greatest camera. I troubleshot it with the guys at Synapse yesterday and it does not seem to be operating correctly. It does not open like it should with the car in the run condition. We tried with it just connected to the B port and it won't even open then, even under throttle. The BOV is on it's way back to Synapse so they can check it out.
 

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I mean in the left video, you hear the flutter for 1-3 secs after you let off the throttle. In the right video you see the bov open the second the throttle is let off. So those can't be the same conditions as if the bov is opening like in the right video when the throttle is lifted, it can't flutter. But that is good synapse is taking care of you, it is hard to troubleshoot long distance.
 

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Weird.

I got compressor surge when I installed it at first because when I talked to Synapse about the BOV they said letting one of the chambers vent to the atmoshere was the most responsive. But since that created surge I connected both and it was fine.
 
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