Knock or detonation will destroy your engine in just a few seconds. Knock, quite simply, is the combustion gasses igniting prematurely or burning too fast. The circuit board along with the firmware we developed filters the normal frequency of the engine to display and record only the detonation. Installation is very easy: Remove one starter bolt to mount the sensor with the provided spacer, mount the controller display unit and supply the power. The control unit also has a relay which can be activated upon repetitive knock events at a user preset limit. The relay can be used to lower your boost via an electric boost controller, inject water, or any other knock control technique.