and then when we use boost
"PCV System (Boost)
Its not really a PCV system, more like a CV (crankcase vent) system under boost conditions. As soon as there is boost in the manifold (anything from 0PSI on up) the PCV is closed. So no more air flow from the PCV. Now you have to imagine the crank case vent hose, and the valve cover vent hoses are flowing air out of them. Since both the valve cover vents and the crank case vent hose are connected to the turbo inlet hose, they will both be putting the blow by back into the engine for re-burning. Because these hoses are before the turbocharger inlet, they will see the vacuum caused by the turbo ingesting air. This helps evacuate the build of blow-by pressure in the crankcase.
The downfall to the blow-by (oil and combustion gases) being sucked into the turbo through from the vents under these conditions is it puts the same oily mess into the turbo, which travels to the intercooler system, then finally back to the manifold. This is much worse than the system under normal conditions as oil in the intercooler cause loss in its cooling ability. So that nice aftermarket intercooler will become less and less efficient over time. Meaning loss in horsepower!! Also this oily mess gets in the boost tubes, and couplers which can deteriorate rubber, and silicone, not to mention cause these connections to come loose!"
"PCV System (Boost)
Its not really a PCV system, more like a CV (crankcase vent) system under boost conditions. As soon as there is boost in the manifold (anything from 0PSI on up) the PCV is closed. So no more air flow from the PCV. Now you have to imagine the crank case vent hose, and the valve cover vent hoses are flowing air out of them. Since both the valve cover vents and the crank case vent hose are connected to the turbo inlet hose, they will both be putting the blow by back into the engine for re-burning. Because these hoses are before the turbocharger inlet, they will see the vacuum caused by the turbo ingesting air. This helps evacuate the build of blow-by pressure in the crankcase.
The downfall to the blow-by (oil and combustion gases) being sucked into the turbo through from the vents under these conditions is it puts the same oily mess into the turbo, which travels to the intercooler system, then finally back to the manifold. This is much worse than the system under normal conditions as oil in the intercooler cause loss in its cooling ability. So that nice aftermarket intercooler will become less and less efficient over time. Meaning loss in horsepower!! Also this oily mess gets in the boost tubes, and couplers which can deteriorate rubber, and silicone, not to mention cause these connections to come loose!"
