What Do You Know About Boost Control? | [TECH NUGGET]

When it comes to controlling boost electronically with an external wastegate, a 3 port solenoid is the most common and for most applications, this is going to be fine. What we do find though is there is a limitation to the range of control due to the way a 3 port solenoid plumbed with boost pressure trying to push the wastegate open from the underside of the wastegate. When it comes to controlling boost electronically with an external wastegate, a 3 port solenoid is the most common and for most applications, this is going to be fine. What we do find though is there is a limitation to the range of control due to the way a 3 port solenoid plumbed with boost pressure trying to push the wastegate open from the underside of the wastegate.

So what is the alternative? One option here is to simply swap out a 3 port for a 4 port solenoid which removes boost from the underside of the wastegate and moves the supply to the top. In this situation, we still have exhaust manifold back pressure trying to force the wastegate open, but we also have boost pressure try to force it closed which gives a greater range of control.
So when might you need this sort of boost control? High powered drag cars are one such example where you might need to leave the line with low boost and low power to maintain traction, and then down the track when traction is available the boost is increased to bring the power levels up and hammer down.

Want to learn more about boost control? Start here.