Anti-Lag
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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Page Contents |
Wiring Tab
Options
Arming Method
Select the method used to activate the Anti-Lag Function.
Engine Demand
Only Engine Demand is used to activate this function.
Switch Only
Only the Switch input is used to activate this function.
Engine Demand & Switch
Engine Demand and Switch condition both need to be met to activate this function.
Connections
Anti-Lag Enable Switch Input
Select an appropriate input to use for the Anti-Lag Enable Switch. An SPI or an AVI (Analogue Voltage Input) can be used.
Connection Type
SPI
An SPI (Synchronised Pulsed Input) requires configuring of the edge and the type of Sensor to be connected.
Edge Select
Falling is used when the input is grounded when the switch is activated. Rising is used when the input is supplied voltage when the switch is activated.
Sensor Type
Set to Hall Effect for all switch inputs
Pullup
Enables a pull up if required to generate a voltage when the switch is off.
AVI
An AVI will require Switch On and Switch Off voltages to be configured so the Elite ECU can know which voltages on the AVI meet the conditions required.
Switch On Voltage
The voltage either above or below where the switch is considered to be ON. When selecting an appropriate value some consideration should be given to allow for voltage fluctuations.
Switch Off Voltage
The voltage either above or below where the switch is considered to be OFF. When selecting an appropriate value some consideration should be given to allow for voltage fluctuations. Eg. if the switch is at 5V when it is Off and is grounded to 0V when the switch is On, you would set the On voltage to 1.0V and the Off Voltage to 4.0V.
Example 1
The switch is at 5V when it is Off and is grounded to 0V when the switch is On. Correct settings with tolerance would be to set On voltage to 0.5V and the Off Voltage to 4.5V. i.e. when the voltage falls below 0.5V it is considered to be ON, and when it rises back above 4.5V it is considered to be OFF.
Example 2
The switch is at 2.5V when it is OFF, and is at 12V when it is ON. Correct settings with tolerance would be to set On Voltage to 4.5V and the Off Voltage to 3.0V. i.e. when the voltage rises above 4.5V it is considered to be ON, and when it falls back below 3.0V it is considered to be OFF.
Anti-Lag Tab
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)
Related Tables
Tables related only to the Anti-Lag function.
Enrichment
This table controls the amount of fuel correction to be applied while anti-lagging. Additional fuel is sometimes required to assist with producing more exhaust energy to keep the turbo spooled. This table is often mapped against Anti-Lag Trigger Time Remaining and will usually have more fuel towards the right hand side and taper away to no additional fuel by 0 seconds.
Ignition Advance/Retard
This table allows for ignition timing to be altered when the Anti-Lag function is active. Typically a large amount of ignition retard is used. This causes the airflow to be maintained but little or no engine torque to be developed. This is turn prevents the engine speed from climbing, but it does allow sufficient exhaust pressure to be produced to maintain a high turbine speed.
Idle Valve Bypass
This table allows the idle valve to provide additional air flow when the Anti-Lag function is active. This table is often mapped against Anti-Lag Trigger Time Remaining and will usually have large amounts of idle output (100%) towards the right hand side and taper away to 0% at 0 seconds.
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