PVS size question

[Surge489]

So I understand the purpose of PVS plugs in that the solid plugs will cause exhaust to bypass the prop and bite more but spin up less. My question is with the open style plugs. I assumed that each size allows for more and more exhaust bypass (from small to large). But thinking in terms of pressure, maybe the opposite is true? Does the open style plug act more like a pressure nozzle? For instance a small plug increases exhaust pressure, where a completely open plug would be less pressure/aerated water? Maybe I’m over thinking it, but the reason I even ask is that I tried 4 large size open plugs on a bravo 1, and had increased holeshot rpm vs removing the plugs completely…by around 400-500 rpm.

[21XDC]

[Surge489]

“Letting a little a more exhaust gas into prop”, so that would be accomplished with a large opening, or as I was saying in the original post, would using a smaller plug opening (say, vs fully open) actually in increase the pressure of the stream of exhaust and increase the aeration? I’ve watched those videos in the past but not sure they’ve ever answered that question.

again, probably over thinking but just envisioning putting your thumb over a water hose. Would love to see a video of varying size holes, the only videos I see are with solid plugs.

[bware]

In my application I’m running large opening plugs. I removed them to see if holeshot could improve but the prop blew-out and I had to feather the throttle to get up on plane.

[21XDC]

There is no exhaust "Pressure" because the prop is wide open in the rear and it takes the path of least resistance...