the place of your stock recirculation valves and release the excess boost pressure when you let off the gas. This keeps the air surge from going back to the turbo putting unwanted pressure on them. These are un-needed since you already have the recircs, they make a cool noise too ;) The boost controller is use to raise your boost levels. You only need to do this if you already have an upgraded ECU which adjusts fuel maps to allow this. You really need to fill out your profile to let people knw just what you have on your car already.
"If everything seems under control, you're just not going fast enough." - Mario Andretti
