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Nicky92 Nicky92 is offline
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Default DVs stay open and dump boost for a split second when I floor it - 05-12-2016, 09:08 PM

I have the MMP inlets. So my Diverter valves do not recirculate, they are left open. I'm doing the bov thing soon but for now I'd like to try to fix this. Some other people I have spoken to do not have this issue with my same set up.

If I'm just coasting and floor it the DVs go pshhhh for a split second, then close and I take off.

What could be causing this? I took the DVs apart and cleaned them up. Same thing.

I think it may have to do with Jb4 settings? Terry? Anyone?


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bradsm87 bradsm87 is offline
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Default 05-12-2016, 10:28 PM

You can't pull OEM DVs apart. What type are they?
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Jameshawk101 Jameshawk101 is offline
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Default 05-13-2016, 04:49 AM

You might have a broken vacuum line.
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Default 05-13-2016, 07:40 AM

They are Forge DVs


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darkrider darkrider is offline
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Default 05-13-2016, 10:13 AM

The beauty of DVs or BOVs for that matter is that they are purely mechanical, so the JB4 settings shouldn't be impacting it, unless they're also impacting your negative boost or vaccuum readings as well, which is unlikely. Are the DVs mounted the same as the stock orientation?

I'm not sure of the push/pull config with the Forge DVs (someone else may be more familiar), but you could try playing with the spring tension. Basically, your vacuum line is always seeing suction (negative pressure) and your charge pipe and inlets sees positive pressure under boost and negative pressure when no boost is applied.

If I had to venture a guess without knowing exactly what the Forge internals look like, I'm guessing that the positive pressure (under boost) needs to overcome the spring tension and vaccuum pressure a little faster, so I'd start with a lighter spring and see if it goes away.
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Default 05-13-2016, 12:16 PM

Quote:
Originally Posted by darkrider
The beauty of DVs or BOVs for that matter is that they are purely mechanical, so the JB4 settings shouldn't be impacting it, unless they're also impacting your negative boost or vaccuum readings as well, which is unlikely. Are the DVs mounted the same as the stock orientation?

I'm not sure of the push/pull config with the Forge DVs (someone else may be more familiar), but you could try playing with the spring tension. Basically, your vacuum line is always seeing suction (negative pressure) and your charge pipe and inlets sees positive pressure under boost and negative pressure when no boost is applied.

If I had to venture a guess without knowing exactly what the Forge internals look like, I'm guessing that the positive pressure (under boost) needs to overcome the spring tension and vaccuum pressure a little faster, so I'd start with a lighter spring and see if it goes away.
They are mounted the way Forge has directed. I will try a lighter spring, as I agree that would fix the issue, hopefully

Thank you


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psychosinmylobby psychosinmylobby is offline
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Default 05-13-2016, 01:51 PM

Quote:
Originally Posted by darkrider
The beauty of DVs or BOVs for that matter is that they are purely mechanical, so the JB4 settings shouldn't be impacting it, unless they're also impacting your negative boost or vaccuum readings as well, which is unlikely. Are the DVs mounted the same as the stock orientation?

I'm not sure of the push/pull config with the Forge DVs (someone else may be more familiar), but you could try playing with the spring tension. Basically, your vacuum line is always seeing suction (negative pressure) and your charge pipe and inlets sees positive pressure under boost and negative pressure when no boost is applied.

If I had to venture a guess without knowing exactly what the Forge internals look like, I'm guessing that the positive pressure (under boost) needs to overcome the spring tension and vaccuum pressure a little faster, so I'd start with a lighter spring and see if it goes away.
You mean a stiffer / heavier spring. DVs don't operate by boost pressure overcoming spring tension. DVs operate by the pressure difference before and after your throttle plate. See:

http://image.superstreetonline.com/f...%2Bdiagram.jpg

When the pressure difference is low I.E. your throttle plate is closed (slowing down / off throttle) and your intake manifold is in vacuum, CP is in boost, the DV will open to vent boost because the pressure difference opens the DV. When you are on throttle, the throttle plate opens minimizing the pressure difference between the intake manifold and the charge pipe. The spring is there to close the DV in this event. If you want the DV to close faster, you will need a heavier spring.
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