Synapse Hybrid Bov Review

[sleeper3]

it's all about the difference in surface area that is being acted upon by the air pressures (even though you can tell this is the case by the drawing). I am going to go out on a limb and assume that the boundary between chambers a and b has MUCH more surface area than the boundary between c and the atmosphere (or intake if you're in recirc). when you're in boost, A and C are pressurized thus holding the valve shut with boost (the spring is acting on it too, but is a non issue at this point), exactly as patty said. if you look at the diagram, this is obvious. when you let off of the gas, chamber A is in vacuum, which opens the valve (since the surface area being effected is greater than that being effected in chamber C (which is still in boost, not vacuum).

to sum up, the pull comes into play when the valve is opening. boost is PUSHING this valve closed. vacuum is PULLING the valve open.

I'd like to see these diagrams of the forge valve too. I think it would shed some light on how it works (at least for me). then again, I am a physics dork and love analyzing stuff like this and making sense of it in my head.

 

[patty AT forge]

Correct me if I'm wrong but...

Its the pressure differential between A and B that opens the valve not A and C. My guess is there is a bleed-hole in chamber C to allow chamber B to pressurize.

The spring IS an issue as it keeps the main valve shut against pressure variations in chamber A and B. Take a look at the diagrams, the shaft mounted plunger is directly actuated upon by movement of the diaphragm that separates chambers A and B and when it is open boost will escape the valve. So ultimately the valve is subject to the same forces as any other. A deviation in pressure seen on that diaphragm due to pressure loss will be the same as a in a "push" style valve. If it is great enough to overcome spring tension the main plunger will open, pressure will drop in chambers C and B, once pressure in chamber B drops low enough the spring will close the valve. Lather, rinse, repeat.

The only part that will remain closed is the secondary plunger as it is free-floating and pressed shut by boost pressure.

And looking at it its impossible for charge-pipe pressure alone to close the valve, no amount of pressure against the back of the secondary valve will keep the main valve closed if the pressure differential between chambers A and B are greater then the spring pressure. So the claim that "Unlike typical push type blow-off valves, the SSQV will not leak under any level of boost because the boost pressure in chamber "C" keeps the valve closed against its seat" is false. What am I missing? I must not be taking something into account.

I can take the spring out of one of our valves and pressurize it beyond the limits of our gauge and it won't leak. Staying closed against some bogeyman of enormous pressure is nothing but marketing. Staying closed against modest pressure variations and opening during large variations is what makes a valve that works.

it's all about the difference in surface area that is being acted upon by the air pressures (even though you can tell this is the case by the drawing). I am going to go out on a limb and assume that the boundary between chambers a and b has MUCH more surface area than the boundary between c and the atmosphere (or intake if you're in recirc). when you're in boost, A and C are pressurized thus holding the valve shut with boost (the spring is acting on it too, but is a non issue at this point), exactly as patty said. if you look at the diagram, this is obvious. when you let off of the gas, chamber A is in vacuum, which opens the valve (since the surface area being effected is greater than that being effected in chamber C (which is still in boost, not vacuum).

to sum up, the pull comes into play when the valve is opening. boost is PUSHING this valve closed. vacuum is PULLING the valve open.

I'd like to see these diagrams of the forge valve too. I think it would shed some light on how it works (at least for me). then again, I am a physics dork and love analyzing stuff like this and making sense of it in my head.

 

[sleeper3]

Correct me if I'm wrong but...

Its the pressure differential between A and B that opens the valve not A and C. My guess is there is a bleed-hole in chamber C to allow chamber B to pressurize.

The spring IS an issue as it keeps the main valve shut against pressure variations in chamber A and B. Take a look at the diagrams, the shaft mounted plunger is directly actuated upon by movement of the diaphragm that separates chambers A and B and when it is open boost will escape the valve. So ultimately the valve is subject to the same forces as any other. A deviation in pressure seen on that diaphragm due to pressure loss will be the same as a in a "push" style valve. If it is great enough to overcome spring tension the main plunger will open, pressure will drop in chambers C and B, once pressure in chamber B drops low enough the spring will close the valve. Lather, rinse, repeat.

The only part that will remain closed is the secondary plunger as it is free-floating and pressed shut by boost pressure.

And looking at it its impossible for charge-pipe pressure alone to close the valve, no amount of pressure against the back of the secondary valve will keep the main valve closed if the pressure differential between chambers A and B are greater then the spring pressure. So the claim that "Unlike typical push type blow-off valves, the SSQV will not leak under any level of boost because the boost pressure in chamber "C" keeps the valve closed against its seat" is false. What am I missing? I must not be taking something into account.

I can take the spring out of one of our valves and pressurize it beyond the limits of our gauge and it won't leak. Staying closed against some bogeyman of enormous pressure is nothing but marketing. Staying closed against modest pressure variations and opening during large variations is what makes a valve that works.

I was assuming that B and C chambers were not connected for 2 reasons. #1 is that they are both named and if they were parts of the same chamber, I don't know why they would do this. #2 is that in drawing number 1, they are not shaded the same color. to me, this indicates a pressure differential. I am assuming that chamber B is either atmospheric pressure, and open, or sealed and at some pressure which makes the valve function as intended.

Also, I never said that boost in chamber C would ever close the valve. I said that it would help HOLD it closed though, since it is added pressure behind a sealed valve which opens AGAINST the force applied to it when C is pressurized.


now that I'm looking at the diagram again, I am also not getting it. it seems to me that figure 1 would be the picture under boost, 2 would be at an idle, and 3 would be when the valve is open and releasing. I don't understand.

 

[patty AT forge]

I'm not saying the you claimed pressure in chamber C would close the valve but that is the implication from their marketing.

Everything you mentioned in the first paragraph I though of but they need to be connected in some way. Sealed with pressure is unlikely for assembly and warranty reasons. Open to atmosphere wouldn't work 'cuz it would make this claim impossible "The SSQV is engineered to initially open the small primary valve at light throttle and load conditions ". If the chamber were open to atmosphere any pressure in chamber A would keep the valve shut, and it would stay shut even with vacuum due to the spring unless the effective diaphragm area in chambers A and B are drastically different.

Picture 1 is high boost, 2 is low boost venting, 3 is high boost venting.

I was assuming that B and C chambers were not connected for 2 reasons. #1 is that they are both named and if they were parts of the same chamber, I don't know why they would do this. #2 is that in drawing number 1, they are not shaded the same color. to me, this indicates a pressure differential. I am assuming that chamber B is either atmospheric pressure, and open, or sealed and at some pressure which makes the valve function as intended.

Also, I never said that boost in chamber C would ever close the valve. I said that it would help HOLD it closed though, since it is added pressure behind a sealed valve which opens AGAINST the force applied to it when C is pressurized.


now that I'm looking at the diagram again, I am also not getting it. it seems to me that figure 1 would be the picture under boost, 2 would be at an idle, and 3 would be when the valve is open and releasing. I don't understand.

 

[sleeper3]

I'm not saying the you claimed pressure in chamber C would close the valve but that is the implication from their marketing.

Everything you mentioned in the first paragraph I though of but they need to be connected in some way. Sealed with pressure is unlikely for assembly and warranty reasons. Open to atmosphere wouldn't work 'cuz it would make this claim impossible "The SSQV is engineered to initially open the small primary valve at light throttle and load conditions ". If the chamber were open to atmosphere any pressure in chamber A would keep the valve shut, and it would stay shut even with vacuum due to the spring unless the effective diaphragm area in chambers A and B are drastically different.

Picture 1 is high boost, 2 is low boost venting, 3 is high boost venting.

I thought the same thing when it came to warranty and the sealed chamber... plus any movement of the diaphragm would DRASTICALLY change pressure in a sealed chamber...

ok looking at it again I think I see what they are doing...

B & C are most likely joined with a small opening... that way, air bleeds from C into B, effecting pressure more slowly rather than all at once. that gives the oportunity for a staged response with the dual valves... it's starting to make sense to me a little, although their claim of not venting at idle still doesn't click.

is that what you're seeing?

 

[patty AT forge]

Hmmm. Maybe chambers A and B are tied together by a small orifice. So when A is suddenly in vacuum A is still pressurized to open the valve but then it bleeds down and as they equalize the valve closes. Which would allow it to close at idle...

 

[sleeper3]

Hmmm. Maybe chambers A and B are tied together by a small orifice. So when A is suddenly in vacuum A is still pressurized to open the valve but then it bleeds down and as they equalize the valve closes. Which would allow it to close at idle...

interesting. there definitely (at least to me it seems like it would have to be there) has to be some sort of bleed effect going on to open a dual staged valve. I didn't even think about an opening between A and B. that's interesting.


our model now, if under boost, is held closed by the spring tension though I think. not boost (excepting the small amount of pressure exerted on the valve in chamber C). the diaphragm is not acting to hold it shut. is that how it works? that would mean that pressure is used to open the valve, and the spring is used to shut it. I'm still kind of new at how all of this works.

 

[patty AT forge]

our model now, if under boost, is held closed by the spring tension though I think. not boost (excepting the small amount of pressure exerted on the valve in chamber C). the diaphragm is not acting to hold it shut. is that how it works? that would mean that pressure is used to open the valve, and the spring is used to shut it. I'm still kind of new at how all of this works.

The majority of clamping pressure will come from boost pressure in chamber A. Pressure in C only serves to close the secondary portion of the valve. The spring just shuts it during variation in pressure and at idle. Pressure AND vacuum open the valve.

...that is if I'm deciphering the diagrams correctly.

 

[AutoXRacer]

Here is another diagram that is some what better represented.

From my personal understanding:

-Diagram 1 is showing how boost conditions seal the primary and secondary valve closed; the concept of pull vs. push.

-Diagram 2 illustrates how low boost/light throttle/load is released through the primary valve at quick actuations by pressure delta between chambers A and B; A and B are sealed chambers from each other.

-Diagram 3 demonstrates the max pressure delta between A and B, the primary valve pulling the secondary valve open for max discharge.

Again, just to make sure... I am just trying to understand; I am not trying to say one is ultimately better than the other.
All am want to convey is why I chose one over the other... And why I personally feel preference over the other with the info that is currently available.

 

[sleeper3]

this still doesn't explain what the pressure in chamber B is dependent upon.

also I noticed something interesting: when the valves are fully open, chamber A is sealed in a vacuum state. I wonder why they did this. maybe it's another indicator that A and B are linked with a small bleed hole.

 

[AutoXRacer]

this still doesn't explain what the pressure in chamber B is dependent upon.

also I noticed something interesting: when the valves are fully open, chamber A is sealed in a vacuum state. I wonder why they did this. maybe it's another indicator that A and B are linked with a small bleed hole.

I think B is a sealed chamber since from the diagram it seems like there is a seal (B = a constant pressure???). Would be interesting to see what the pressure is in chamber B; might be ambient during assembly. I did not see any bleed holes or anything like that when I installed mine. The shaft seemed sealed as well.

(huh)

 

[sleeper3]

I think B is a sealed chamber since from the diagram it seems like there is a seal (B = a constant pressure???). Would be interesting to see what the pressure is in chamber B; might be ambient during assembly. I did not see any bleed holes or anything like that when I installed mine. The shaft seemed sealed as well.

(huh)

Chamber B being sealed is kind of hard for me to believe considering what has already been talked about in this thread. I guess it is possible though. it's just that a sealed chamber would apply a LOT of force to the diaphragm when the valve is open. plus if there was ever a leak, it wouldn't be good. I don't know. seems odd.

 

[pidass15]

Installed it yesterday. Pain the ass for BPV install. I don't see anyway to do it without cutting the hose with Cobb SRI but it fits perfectly when the hose is cut some. Sound is little louder than stock and much more pleasing than the Forge. I couldn't tell any power difference but then again I don't have a sensitive butt dyno so there may or may not be power difference.

 

[Crazee D]

I am looking to buy, anyone selling? Also considering the synapse WG