How Turbocharger Wastegates Work: Understanding Internal and External Methods

Hello everyone and welcome to this video, where we're going to discuss how turbocharger wastegates work and explore the two methods used. You know that wastegates are essentially bypass valves, which allow exhaust gases to bypass the turbine of the turbocharger and exit straight out of the car.

To begin with, let's examine an internal example. We have our exhaust portion here, which includes the exhaust turbine, and then we have the inlet portion with the compressor wheel. As air enters this system, it creates boost that enhances power in your vehicle. When the exhaust spins up to provide more boost at a certain point, the pressure reaches a level where it travels through what I call a vacuum line. Under most conditions, this line is a vacuum, but when under boost, it becomes above atmospheric pressure. For instance, we have a 10 psi wastegate actuator here, which is a pneumatic actuator.

The action of this actuator is as follows: as the pressure in this actuator rises, it pushes up the diaphragm attached to the spring. As the diaphragm pushes up on the spring, it causes the valve to pivot about the point right there, resulting in its rotation and opening. The exhaust gases no longer need to travel through the turbine; instead, they can bypass directly out of the car. This process is entirely dependent on what you set this spring at, so if you set this spring at a stiffer rate, it will have more boost; setting it at a lower rate will open up at lower boost pressures and allow you to bypass the turbocharger sooner.

Now, let's explore the advantages of this setup. One significant benefit is that it's compact, requiring less piping and accommodating the exhaust system as designed to travel through the catalytic converter and muffler. This makes it an excellent solution for OEM vehicles, which inherently need to comply with such requirements. Moving forward, we'll discuss external wastegates.

External Wastegates: An Alternative Method

Moving on to external wastegates, we have our engine and turbocharger positioned side by side. The primary difference between this setup and the internal method is that the waste gate lies outside of the turbocharger housing. When air enters at a certain point, pressure builds up and travels into our pneumatic wastegate.

The role of this actuator is straightforward: it presses in on the spring that opens the valve, allowing exhaust gases to exit directly out of the engine without needing to pass through the turbine. This external method achieves the same goal as its internal counterpart but does so by bypassing the turbocharger's presence entirely.

There are several reasons why you might prefer using an external wastegate over an internal one. For instance, this setup allows for more flexibility in terms of where the exhaust gases can exit. The design of this system enables it to be reconnected with the exhaust further down the line, which enhances turbine efficiency and results in improved performance. This adaptation also makes it suitable for racing applications, where direct venting into the atmosphere could offer an advantage.

Another significant benefit of using external wastegates is that you're not limited by the size of your turbocharger housing to create the desired setup. You have more freedom to choose the appropriate valve and design as needed to suit your specific needs.

Conclusion

In conclusion, we've explored both internal and external methods for implementing wastegate functionality in your vehicle's turbocharger system. Understanding how these systems operate can help you make informed decisions about upgrading or maintaining your engine's performance capabilities. If you have any questions or comments regarding the material discussed in this video, please feel free to share them below.

"WEBVTTKind: captionsLanguage: enhello everyone and welcome in this video we're going to be talking about how turbocharger wastegates work and the two methods used so we've got internal and external and you know wastegates really are just bypass valves so the exhaust gases can bypass the turbine of the turbocharger and just go straight out of the car so here we have an internal example and so we're going to start with this so we have our exhaust portion here the exhaust turbine and then we have the inlet portion here with the compressor wheel and so your air is going to be coming in here creating boost stuff for your car to make more power so as this exhaust is spinning up and providing more boost at a certain point that boost is going to reach a certain pressure and that pressure is going to travel through this vacuum line i call it a vacuum line because under most conditions it's going to be a vacuum but when you're under boost of course it's going to be above that so let's just say this is a 10 psi wastegate actuator here so this is a pneumatic actuator and so as the pressure in this actuator rises it pushes up this thing here so you've got this diaphragm which is going to push up on a spring and as that diaphragm pushes up as you can see it's going to pivot about this point right here so it's going to push up this is going to rotate and it's going to open up this valve so the exhaust gases no longer have to travel through the turbine and instead they can just bypass that directly and head out the exhaust so it's all dependent on what you set this spring at so if you set this spring at a stiffer rate it'll have more boost if you set sit at a lower rate it'll open up at lower boost pressures and so you can bypass that turbocharger sooner now what are the advantages of doing something like this well it's compact there's less piping and the exhaust by design has to travel through the catalytic converter and through the muffler and so this is a great solution for oem vehicles out there which of course have to do that now let's move on to external wastegates so here we have our example we've got our engine here with our turbocharger the inlet side and the exhaust side so as it pulls in air uh you know you get to a certain point and the only difference really here is that this waste gate is not within the turbo housing and so that pressure then travels through travels into our pneumatic wastegate which we have here the pneumatic actuator and so that presses in the spring that spring opens up this valve and so the exhaust gas is coming out of the engine instead of forcing them to travel through the turbocharger the exhaust portion in the turbine they can travel directly through this valve here and bypass that turbocharger so it's doing the exact same thing but there's another way of doing it which is the external method and you can also you could just dump this directly into the atmosphere you don't have to put it right back into the exhaust piping but the reason you would do something like this with an external wastegate is that you can rejoin the exhaust further down the line it doesn't have to be right at the turbocharger and this improves the turbine efficiency so you're going to get more performance out of it and it also could be routed directly to the atmosphere for example for a racing application so if you didn't want to route it into here you don't have to whereas in this case it's always going to be routed into the exhaust and here you could just have it vent directly to the atmosphere also the benefit of doing a wastegate externally is that you can choose any size you want you're not restricted by the size of the turbocharger housing in order to make it work you can do any size you want and so that gives you a little bit more free play in the design of it so if you guys have any questions or comments feel free to leave them below thanks for watchinghello everyone and welcome in this video we're going to be talking about how turbocharger wastegates work and the two methods used so we've got internal and external and you know wastegates really are just bypass valves so the exhaust gases can bypass the turbine of the turbocharger and just go straight out of the car so here we have an internal example and so we're going to start with this so we have our exhaust portion here the exhaust turbine and then we have the inlet portion here with the compressor wheel and so your air is going to be coming in here creating boost stuff for your car to make more power so as this exhaust is spinning up and providing more boost at a certain point that boost is going to reach a certain pressure and that pressure is going to travel through this vacuum line i call it a vacuum line because under most conditions it's going to be a vacuum but when you're under boost of course it's going to be above that so let's just say this is a 10 psi wastegate actuator here so this is a pneumatic actuator and so as the pressure in this actuator rises it pushes up this thing here so you've got this diaphragm which is going to push up on a spring and as that diaphragm pushes up as you can see it's going to pivot about this point right here so it's going to push up this is going to rotate and it's going to open up this valve so the exhaust gases no longer have to travel through the turbine and instead they can just bypass that directly and head out the exhaust so it's all dependent on what you set this spring at so if you set this spring at a stiffer rate it'll have more boost if you set sit at a lower rate it'll open up at lower boost pressures and so you can bypass that turbocharger sooner now what are the advantages of doing something like this well it's compact there's less piping and the exhaust by design has to travel through the catalytic converter and through the muffler and so this is a great solution for oem vehicles out there which of course have to do that now let's move on to external wastegates so here we have our example we've got our engine here with our turbocharger the inlet side and the exhaust side so as it pulls in air uh you know you get to a certain point and the only difference really here is that this waste gate is not within the turbo housing and so that pressure then travels through travels into our pneumatic wastegate which we have here the pneumatic actuator and so that presses in the spring that spring opens up this valve and so the exhaust gas is coming out of the engine instead of forcing them to travel through the turbocharger the exhaust portion in the turbine they can travel directly through this valve here and bypass that turbocharger so it's doing the exact same thing but there's another way of doing it which is the external method and you can also you could just dump this directly into the atmosphere you don't have to put it right back into the exhaust piping but the reason you would do something like this with an external wastegate is that you can rejoin the exhaust further down the line it doesn't have to be right at the turbocharger and this improves the turbine efficiency so you're going to get more performance out of it and it also could be routed directly to the atmosphere for example for a racing application so if you didn't want to route it into here you don't have to whereas in this case it's always going to be routed into the exhaust and here you could just have it vent directly to the atmosphere also the benefit of doing a wastegate externally is that you can choose any size you want you're not restricted by the size of the turbocharger housing in order to make it work you can do any size you want and so that gives you a little bit more free play in the design of it so if you guys have any questions or comments feel free to leave them below thanks for watching\n"