The boost return tube that passes the diverted air back to the g-lader supercharger when at partial or minimal throttle position also carries oil vented from the valve cover breather into the supercharger. This oil lubricates the wear strips or apex strips inside of the supercharger and it is an engineered in feature of the system. If you eliminate the boost return tube and block off the return side of the g-lader it is recommended that you also run an oil breather tube back into the block off plate from the valve cover breather. This will maintain the lubrication in the g-lader. It is our opinion that eliminating the boost return generates minimal to no gains in performance. Dumping the bypassed air to atmosphere can cause an air rushing sound when driving out of boost or when driving at partial throttle cruising conditions. The BBM screw type compressor does not require this oil mist for internal lubrication therefore you can run it in either configuration. For additional information or questions on this topic please search or ask thewww.vwvortex.com forums.
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