Technical Partial Throttle Surging/Oscillation Noises from BOV

[cityazndan]

Hello,

Is there a way to tune out or alleviate partial throttle boost oscillation? I have the VS MAP sensor relocate on deck but was wondering it this is a tune issue. Right now, I'm stacked JB4 with MHD BEF.

The sound is exactly like in the video car (0:12 - 0:17 seconds), turn up the speakers to hear the audible oscillation, almost surging. I have logs as well capturing the oscillation between 1.3-1.7psi. Sounds bloody awful cruising around.

 

[Torgus]

Bov line upgraded?

Correct spring in there?

Can you grab a buddies bov and see if it reacts the same way?

 

[dyezak]

Sounds like BOV flutter. Need a full 1/4" line from your intake manifold to the BOV. Tial has made it pretty clear on the tech sheet they require this http://tialsport.com/documents/w3_tial_qqr_sp.pdf

And as much as you might not like him, Tony Vargas has addressed this on many occasions as well explaining why the Tial needs a full 1/4" line.

 

[cityazndan]

Right now I'm using a Synapse BOV, I have my buddies Tial QRJ on hand. installing the VS adapter is similar to tapping the manifold. I have a 1/8 to 3/8 barb from the adapter so it matches the 3/8 (10mm) end from the Tial. Currently using verocious Motorsports platinum cured vacuum hose. Will get 6mm ID hose next. My only concern is why are we using a 1/4 (6mm) dedicated line when the barb end if 10mm....unless the barb end ID is 6mm....

 

[doublespaces]

1/4 line absolutely necessary. I use a very light spring also, there is no reason to use a tight spring, its not going to kill your car to have the bov open at idle.

 

[cityazndan]

The Synapse BOV isn't designed like the Tial (pull valve), but my buddy's Tial has the OE 3lbs spring. I might re-install the preload spring for the Synapse as big boost guys take it out (PO was running 33psi on a Xona).

 

[themillsbros]

I am getting the same exact noise with my synapse. did you find a solution?

 

[cityazndan]

I ended up ditching the synapse and going Turbosmart and never looked back.

 

[themillsbros]

I ended up ditching the synapse and going Turbosmart and never looked back.

Damn. According their FAQ I can try adjusting the screw or going to port b only. Ill give it a try tomorrow...

 

[themillsbros]

Changed to port B seemed to alleviate some of the noise, cranked down the adjustment screw, back to making that noise.... Looks like ill be looking at new bov/pipe =\