A fixed boost controller is not exactly a 'controller', rather it tricks the wastegate actuator into staying closed until higher boost levels are reached. The wastegate actuator will open when it reaches a pressure of 7.3 psi. By bleeding off pressure before it reaches the wastegate actuator, you can increase the amount of boost the turbo delivers.
For example, if you bleed off 3 psi before it reaches the wastegate actuator, the turbo will spin up to 10.3 psi before the wastegate opens.
A fixed boost controller is a good idea if you want a simple increase in horsepower without having to run extra hoses into the passenger compartment, such as with the Adjustable Boost Controller.
Turbo Hoses
The image below is a view from the intake side of the turbocharger. The solenoid's function involves three hoses:
Boost Solenoid
The boost solenoid is located just below the turbo inlet on the intake side. In the image below, the three hose connections as described above are labeled.
Solenoid is upside down compared
to actual mounting position.
Required
Scissors or knife
18" of ¼" vacuum hose
¼" plastic vacuum hose connector
Procedure
Disconnect hose #1 at the turbo and hose #2 at the wastegate actuator.
Take the 18" of vacuum hose and cut it in half. Less hose can be used, but will make adjustments more difficult. Reconnect the two halves using the hose connector.
Attach the hose in place of the solenoid, connecting one end to the turbo and the other to the wastegate actuator.
Using a small drill bit, drill a hole into the connector at the middle of the hose.
Drive the vehicle and see how high the boost level reaches.
Repeat steps 4 and 5, drilling larger or additional holes into the connector until the boost level is at the desired level.
NOTE: If you decide to remove the solenoid, make sure you plug up the hole in the intake tube where hose #3 connected to.
