Burkey
Well-Known Member
My point is that slowing the rate of opening/closing won‘t alter the actual open/close maximum points.When a bypass valve doesn’t open or close when it’s supposed to you can lose boost. If it’s not closing all the way at WOT for example you can lose boost which is common. By controlling the vacuum, it frees up boost that would’ve been there if the bypass valve had been working properly from the beginning. The valve still is opening and closing in a delayed manner on start up but it seems to be functioning better overall now. But this isn’t something I just did. My shop did it and revised the tune based on the airflow change.
I‘m going to suggest that they may have played with the cam timing which will most certainly produce more or less boost if you so desire.
Vacuum should be very low at WOT, ergo the spring holds the valve closed, vacuum pulls it open.
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