The slight upward cant of the GVW50 wastegate valve housing on the left was the direct result of CFD optimization.
Here is the flow data on the GVW wastegates versus other top wastegates in benchmark testing. Garrett flows right up there with the best of them.
The GVW wastegates are designed to take the heat without being fazed. In fact, in testing the GVW wastegate outperformed the competition in maximum temperature resistance, heat cyclic durability, and heat-affected hysteresis or response time lag. You can see how this generous stainless steel heat shield helps protect the actuator body from the heat radiating from the valve housing.
The valve seat is subjected to erosion from hot corrosive gasses. We have had this issue in many race cars ourselves. To combat this Garrett has made the valve seat from high heat, wear, and corrosion resistant stainless.
The valve seat is also a separate piece and is easily removable. It is available separately as a service part. With other wastegates, we have had to lap the valve seat periodically to maintain sealing or have had to cut off and reweld a flange with a built-in seat. We have also had seats warp due to welding heat when installing them. With Garrett, it’s just a few minutes to replace the seat.
The GVW wastegates use state-of-the-art materials in their construction to insure temperature resistance and reliable cycling. The valve body is cast of high-temperature stainless steel, the valve is also high temp stainless steel with an anti-galling plated stem. The valve guide bushing is made of Nitronic 60, a high temp alloy known for its corrosion resistance and anti-galling capability. These materials allow the GVW wastegates to be rated up to an amazing 1922 degrees! We have stuck open wastegates and lost boost before on cars running pure ethanol and corrosive scale-producing fuel like LSR racing spec fuel so we can appreciate these steps to reduce the chances of valve stem sticking.