Cartridge GT4288 703072-0004 452109-0008 Scania Truck

What is thrust bearing oil ramping?
Oil ramping is designed to allow the thrust bearing to resist thrust forces put on it. It is essential to understand the importance of oil ramping and the part this plays in reducing wear and prolonging the turbos life. The ramp sizing is barely visible but is an extremely important feature on the thrust bearing. It creates a wedge of oil as the thrust component rotates and helps to force the parts away from the surface, reducing wear and therefore increasing the turbos life.

Do I really need the cool down procedure on my turbo?
The need for a cool down procedure depends on how hard the turbo and engine is used, and whether or not the turbo is water-cooled. All turbochargers must pass a heat soak test and the introduction of water-cooling has virtually eliminated the need for a cool down procedure.

How does a Waste gate work?
A Wastegate is simply a turbine bypass valve. It works by diverting some portion of the exhaust gas around, instead of through, the turbine. This limits the amount of power that the turbine can deliver to the compressor, thereby limiting the turbo speed and boost level that the compressor provides.

What is the Exducer?
Looking at a compressor wheel, the exducer is the "major" diameter. For a turbine wheel, the exducer is the "minor" diameter. The exducer, in either case, is where flow exits the wheel. Compressor wheel exducer diameter is incorporated into GT-series nomenclature: The "60" in the GT2860RS for example, has a 60mm compressor wheel exducer diameter.