The Anti-Lag function is used with turbocharged engines to increase turbine speed when the throttle has been closed. This is typically of use during gear changes to prevent the turbo from stalling and needing to build pressure again after the throttle is re-opened.

The amount of pressure developed by the turbo is primarily controlled by the amount of additional air being provided. This additional air can be delivered via the idle control system, or it can be delivered via the throttle body. To provide additional air via the throttle body, the throttle stop is set so that the desired amount of additional air required is delivered and then the TPS (throttle position sensor) re-calibrated to be 0% at closed throttle. To keep the idle speed at a normal level the Rotational Idle function should then be Enabled and configured. DBW throttle application do not require Rotational Idle as the throttle can be controlled during anti-lag operation and does not require changes to the throttle stop.

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Settings shown are for example purposes

Anti-Lag Options

Arming Engine Demand

The amount of Engine Demand (TPS for Cable Throttles or APP for DBW Throttles) that must be exceeded to arm the Anti-Lag function. This is used to initially develop enough air flow to have an effect when the throttle is closed. (Default=50)

Activating Engine Demand

The amount of Engine Demand (TPS for Cable Throttles or APP for DBW Throttles) that must drop below to activate the Anti-Lag function. (Default=1.0)

Min RPM

The Anti-Lag function will disable below this amount of RPM. (Default=3000)

Max Time

The maximum amount of time that the Anti-Lag function will operate until conditions have all been again met. This is to prevent possible engine damage if an excessive amount of time is spent in anti-lag conditions. (Default=5.00)

Max Coolant Temp

The Anti-Lag function will be disabled above this amount of Coolant Temperature. This is to prevent possible engine damage due to an overheated engine. (Default=110C)

Min Coolant Temp

The Anti-Lag function will be disabled below this amount of Coolant Temperature. This is to prevent high levels of engine wear when using Anti-Lag with a cold engine. (Default=60C)

Max EGT

Available when an EGT sensor is configured. The Anti-Lag function will be disabled above this amount of EGT. This is to prevent engine damage due to excessive exhaust temperatures. (Default=1000C)

Max Turbo Speed

Available when a turbocharger RPM sensor is fitted and utilised. Used to prevent overspeed of the turbocharger.

Intake Air Valve Frequency

Controls the duty cycle used to open an intake air bypass valve to provide additional air flow where fitted.

Exhaust Air Valve Frequency

Controls the duty cycle used to open the exhaust anti-lag exhaust valve where fitted.