I read the article on turbochargers on howstuffworks.com like a few of you recommended. However, it just talked about the basics of the turbo itself. It mentioned wastegates but that is it. I am pretty familiar with how turbochargers themselves work. But I don't get all the stuff about wastegates, waste gate actuators, boost controllers, etc. Can someone please explain this to me? To my understanding, the waste gate lets hot gases bypass the turbine blades. The WGA controls how much hot gases bypass the turbine blades and i'm guessing the boost controller some how controlls the boost. Can someone please help me out. What is the purpose of buying aftermarket WGAs ang boost controllers? Thanks alot

 

The Waste Gate (WG) controls how much boost the turbo produces.

Inside the Waste Gate Actuator (WGA) is a spring and a rubber diaphram. A Vacuum/Boost line runs from the pressure side of the turbo to the WGA. Once the turbo is producing enough pressure to overcome the spring in the WGA, the boost pushes the WGA open allowing the exhaust to bypass the turbo, effectively slowing the turbo down making it produce less boost.

A boost controller goes in the vacuum/boost line between the WGA and the turbo. Typically Manual Boost Controllers (MBC) are either ball & spring, bleeds or a combination of ball & spring and bleeds. A ball & spring MBC prevents the boost from reaching the WGA until the boost overcomes the spring in the MBC. A bleed type MBC has a needle valve and a hole which will bleed off the boost in the vacuum/boost line to the WGA, lowering the ammount of boost that reaches the WGA.

Electronic Boost Controllers (EBC) use a solenoid to open and close the line to the WGA. The EBC cycles open and closed at a very high rate. By the time the air gets to the WGA it is "averaged out" to a particular level. When the EBC wants more boost it will be closed more than open. When the EBC wants less boost it will be open more than closed.

 

Thank you so much for explaining all that to me. So, with a higher psi WGA the turbo will produce more boost until it overcomes the spring, right? Also, how do you set the boost contoller? Does it have some sort of dial or something? Please forgive the stupid questions. I'm trying to learn everything I can about our turbos. Thanks

 

Yup. My turbo upgrade came with two springs for the WG, one 10# spring and one 15# spring. The 10# spring will provide 10psi of boost and the 15# spring will provide 15psi of boost, without any boost controller.

MBC's have a screw or **** you turn to change the boost.

EBC's you change through it's settings on it's display.