Boost Timing Master For Use With Control Perfect For Roots Blowers Looking For Basic Timing Retard Based On Boost. Includes Dash Mounted Retard Knob MSD IgnitionThe Boost Timing Masters allow you to adjust the amount of ignition retard from 1 Degree per pound of boost to 3 Degree per pound via a control knob that you mount on the dashboard. This way you can make adjustments on the fly to prevent detonation as fuel quality or altitude and air quality changes up to a maximum of 15 Degree retard. You can also set a boost pressure point to start the retard. There is a boost pressure port to connect to your