Rotational Idle
Rotational Idle is used to maintain a normal low idle speed when a fixed larger amount of air is being used for lift-off Anti-Lag purposes, or you just want to sound like a legend when your engine does not perform. An example is where the throttle body has been opened to provide the additional air to the engine when the accelerator pedal is released. Without Rotational Idle, the engine would idle excessively high. To control the idle the Elite ECU will cycle through cylinders to be cut to keep the engine below a set RPM amount. As RPM approaches this set amount more cylinders are cut.
Rotational Idle is not required for all Anti-Lag configurations, only those configurations where the additional air flow is not switchable.
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Page Contents |
Wiring Tab
Options
Rotational Idle Switch
Select if a switch is to be wired to the Elite ECU to enable or disable the Rotational Idle function.
Connections
Active only when the Rotational Idle Switch has been Enabled.
Switch Input
Select an appropriate input to use for the Rotational Idle 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 pullup 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 the 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 the 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.
Settings Tab
Activating Engine Demand
The amount of TPS opening for cable throttles, or Accelerator Pedal opening for Drive-By-Wire throttles, below which the Rotational Idle function will be active.
Idle Valve Position
The amount of idle valve opening to be used when the Rotational Idle function is active.
End RPM
When Rotational Idle is active, this is the amount of RPM above which all cylinders will be cut. This should be set to give the engine a stable idle and is typically set a little higher than an amount of RPM the engine would normally idle with when there is no Anti-Lag system.
Cut Method
Select which outputs to cut in order to limit engine speed while rotational idle is active.
Ignition
Ignition outputs will be disabled to limit engine speed. This is commonly used in applications where fuel flow is required to cool the engine.
Injection
Injector outputs will be disabled to limit the engine speed. This is the most commonly used cut method for rotational idle.
Conditional Activation
Condition Enable
Select whether to enable a particular condition to enable or disable the Rotational Idle Function. This must be Enabled when a switch has been configured in the Wiring Tab.
When Rotational Idle Switch is On
And/Or
Allows an additional condition to be used to enable the Rotational Idle Function, or just the switch input alone.
Select
Allow selection of the ECU channel to be used.
Maths
A selection of Equal To, Not Equal To, Greater Than, Less Than, Greater Than Or Equal To, Less Than Or Equal To that is to be used.
Value
The value the maths must meet.
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