saviour stivala wrote: ↑20 Aug 2018, 12:38
No the waste-gate/s are not positioned to vent exhaust turbine scroll. The waste-gates are positioned to bypass exhaust turbine scroll.
None of the four formula one engines uses a build-into-the-exhaust turbine scroll housing waste-gate/s. build- into-the-exhaust turbine scroll housing waste-gate can only relieve exhaust turbine scroll pressure to control compressor boost and not bypass the exhaust turbine scroll to eliminate back pressure so as the compressor can be operated in electric supercharging mode. A waste-gate positioned on top of the exhaust turbine housing doesn’t mean it is build into said housing.
I think you talk about an internal wastegate and external wastegate. Although it is true, that an internal wastegate is integrated into the turbine housing, That doesn't mean an external wastegate can't vent the exhaust from the turbine scroll. The thing that defines internal vs external is actually where the mechanism to bypass the turbine is located. An internal wastegate has the "valve" basically in the turbine housing. In an external wastegate doesn't. So if i drill a hole into the exhaust turbine scroll and screw the "valve" on it, it's an external wastegate although it vents the exhaust gases from the turbine housing.
The wastegates used in F1 are fully electronically controlled anyway. So i'm not even sure it would be fully appropiate to call them internal or external, because they are different than most wastegates you can buy for automotive use anyway.