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Max Sluiter
 
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Join Date: Mar 2006
Location: So Cal
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Everything on a main oil galley or line sees (basically) the same pressure: the same pressure that your cockpit gauge measures. After a restriction or opening such as a bearing, the pressure is low and it spills down to the sump to be sucked up into the tank then re-pressurized.

Because your turbo sees this constant pressure, a restrictor in the line will decrease the flow to the turbo if you maintain the same pressure you had before the restrictor.

The restrictor will speed up flow until the fluid reaces its critical velocity (like the speed of sound) for its particular viscosity. This is because the oil pump is a constant-displacement type so it wants to pump a certain volume and will use as much pressure as needed to do so. Once the critical velocity is reached in the restrictor, it is effectively stalled or plugged and pressure goes way up for no increase in flow. Before this point, your oil pressure limiting bypass piston will have come into effect, just as if you were revving a cold engine. This is why the oil pressure is constant past a certain point and why the restrictor limits oil flow volume. It is the same principle as the cam box oil line restrictors, which I do not use.
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911S
1971 chassis, 2.7RS spec MFI engine, suspension mods, lightened

Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance
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Old 05-08-2010, 12:01 AM
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