[BullShifter]

Dry sump stores oil in an external tank keeping the oil pan pretty much "dry" which reduces internal friction, increasing overall power.

Unlike a wet sump system where oil is stored in the pan, a Dry Sump Oiling System stores oil in a separate tank - leaving the pan essentially "dry." An extemally-mounted pump, generally with three or four stages, is used to "scavenge" or remove oil from the pan, deliver it to the storage tank, and send it back through the engine. In a typical setup, all but one of the stages is used to scavenge oil from the pan. A single pressure stage is normally used to return oil from the tank to the engine.

The primary advantage of a Dry Sump System is its ability to make more power. With very little oil in the pan, the rotating assembly is not burdened with the weight of excess oil (a phenomenon commonly referred to as "windage'). And because there is no internal pump, the windage tray or screen which serves to isolate sump oil from the rotating assembly, is allowed to run the full length of the pan. Keeping the rotating assembly free of windage allows it to spin freely and make more power. In addition, the extra crankcase vacuum created by the dry sump pump helps to improve ring seal for additional power gain.

For more info : http://www.performance-corner.com/ht...tips02-00.html