There is no exact science to the PVS plugs and there is no exact science to any setup. All can be different due to loads, differences in props, differences in engines, altitudes, and weather conditions. Take out another plug and see what happens. If you have a cavitation ring, take it off. There are many different ways to get where you want to be. If youre in the right rpm range at top end speed, you can get the right hole shot by adjusting the PVS plugs and/or cavitation ring.