Auxiliary RPM Limiter

Auxiliary RPM Limiter

The Auxiliary (Aux) RPM Limiter function is used where a temporary lower RPM Limit is required. This is sometimes used for basic launch control or valet purposes. The Aux RPM Limiter requires an input to the Elite ECU to activate this function.

Page Contents

Wiring Tab

Connections

AUX RPM Limiter Switch Input

Select an appropriate input to use for the Aux RPM Limiter 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.

Aux Rev Limit Tab

Cut Type

Select how the RPM Limiter is to be applied.

Hard Cut

All cylinders are cut at the end RPM and resume operation when the RPM has fallen below the RPM Limit value by the Hysterisis amount.

Soft Cut

The Elite ECU will use an algorithm to randomly cut individual injection or ignition outputs to maintain engine speed at or below the End RPM. This is calculated on a per-firing-event basis, and results in a faster and smooth engine limiter.

Cut Off

Select Cut Off in order to limit engine RPM by applying a user definable percentage cut, with user definable cut pattern, resulting in smoother or rougher cuts as requested. This can change the sound of the RPM limiter.

Cut Method

The method used by the function to limit the engine RPM.

Ignition

Ignition Outputs will be cut. This is the more common method.

Fuel

Injection Outputs will be cut.

Fuel & Ignition

Both Injection Outputs and Ignition Outputs will be cut.

Related Tables

RPM Limit

Under ECU Navigator>RPM Limits>Aux RPM Limiter>select RPM Limit

When above or at this engine RPM, the Auxiliary RPM limiter will activate to reduce the engine speed, and the Cut Method and Type will be applied. This can be mapped in 2D.

Cut Hysteresis

Under ECU Navigator>RPM Limits>Aux RPM Limiter>select Cut Hysteresis

Available only when the Cut Type is set to Hard Cut. The engine speed must fall this amount below the RPM Limit before injection or ignition is re-enabled.

Cut Percentage

Under ECU Navigator>RPM Limits>Aux RPM Limiter>select Cut Percentage

Available only when the Cut Type is set to Cut Off. Allows the user to apply a user definable percentage cut to the engine, over a range of conditions. This can be mapped in 3D (8x8).

Adder

Under ECU Navigator>RPM Limits>Aux RPM Limiter>select Adder

Available only when the Cut Type is set to Cut Off. The Adder value changes the pattern in which cylinders are cut. Recommended values for the Adder value setting which will ensure the most even pattern and the smoothest cut are shown below. Generally, using adder values that are further away from these values will produce less even cut patterns and rougher cuts. The recommended values are dependent on the number of cylinders. This can be mapped in 3D (8x8).

Number of Cylinders

1

2

3

4

5

6

7

8

9

10

11

12

Recommended Adder Value

151

151

187

147

198

197

193

179

191

197

201

207

    • Related Articles

    • RPM Limiter

      The RPM Limiter is used to prevent engine damage by shutting down injection or ignition outputs at a set engine speed. Page Contents RPM Limiter Tab Cut Method Injection Ignition Cut Type Hard Cut Soft Cut Hysteresis Related Tables RPM Limiter End ...

    • RPM Limiter Correction

      This table controls the fuel correction applied as the engine RPM approaches the Main RPM Limiter End RPM.  Generally, a small correction is made just before the engine reaches the RPM limiter to help soften the effects of the limiter. 

    • RPM Limiter Ignition Correction

      RPM Limiter Ignition Correction This table controls how many of degrees of ignition timing correction will be applied as the engine approaches the rev limiter

    • Torque Converter Control Function

      The Torque Converter Control function allows the electronic control of the torque converter lockup, as well as the ability to "dump" torque converter line pressure in order to control engine power in a drag racing application, as well as assisting ...

    • LPG Function

      LPG function is used when a vehicle has a LPG system fitted to the engine.Wiring a switch input for LPG select enables the ECU to disable the injectors and fuel pump when the LPG switch is active. Page Contents Wiring Tab Connections Switch Input ...