Turbocharger oil scavenging has always been an issue. You might have 50 psi feeding the turbo but the slightest restriction in the "drain" will immediately send oil past the exhaust seals, burning up oil and ruining your turbo. In the case of remote mounted turbo systems, rear mounted systems, or in systems mounted below the engine oil level, some form of positive scavenging has to be engineered. That is where this pump comes into play.