Torque Management
The Torque Management function is designed for drag racing applications, managing engine torque in order to maintain optimal wheel speed, resulting in optimized grip, acceleration and ultimately race times.
This function allows you to program a desired ‘’Target RPM’’ for either Driveshaft RPM, Engine RPM or both verses a range of different operating conditions. If the controlled variable goes above the ‘’Target RPM’’ user defined value, an extremely fast control system reduces engine torque by retarding the ignition timing and/or cutting individual cylinders until the controlled variable speed falls below the user defined value target.
The amount of ignition retard, as well as when to use cylinder cut is determined from the user-configurable tables in the ESP software. Additional torque reduction can be achieved by reducing boost or delaying a stage of nitrous. It is important to note that Torque Management will never advance the ignition timing past your ignition base table. If there are pre-programmed timed ignition retards active and the controlled variable speed falls below the target, the torque management can override these pre-programmed timed ignition retards.
The Torque Management function is available with the Elite 2500T, Elite VMS T and Race Expansion Module. The Race Expansion Module must be connected to the Elite 2500 ECU through Haltech CAN in order for Torque Management to function.
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Wiring Tab
Options
Arm Method
Select from the following:
Always on
Torque Management will always be on.
Switch
Allows the user to turn Torque Management on or off with a switch.
Race Timer
This function requires a ”Race Timer” to be setup in the software. The Race Timer would typically be triggered from a Transbrake release or Clutch release. The "Driveshaft RPM Target" and/or "Engine RPM Target" would then be mapped verses the "Race Time". This is the most common use for this function.
Armed Output Enable
Ticking this box will add the ”Armed Output” pin assignment to the Connections list.
The purpose of the ”Armed Output” is to provide a visual indication, such as LED light to the driver that the Torque Management function is armed and will function as configured.
Torque Management Knob Enable
Ticking this box will add the ”Torque Management Knob Input” pin assignment to the Connections tab.
By wiring a Trim Knob (Rotary Switch) to an analogue input you can adjust the "RPM Target" to choose up to 8 different curves. This makes adjusting the curve very quick and easy when you are sitting at the start line and notice the racetrack has improved or gone off from the run before you. This is accomplished by using the knob position as one of the input axes of whichever Torque Management tables the tuner desires.
Connections
Torque Management Switch
Select an appropriate input to use for the Torque Management Switch. Typically, an AVI (Analogue Voltage Input) is used.
Armed Output
Select an available output wire, typically a DPO (Digital Pulsed Output) or Stepper Output will be used.
Torque Management Knob Input
Select an appropriate input to use for the Torque Management Knob Input. An AVI (Analogue Voltage Input) or an SPI (Synchronised Pulsed Input) should 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.
Knob Calibration Tab
This allows calibrations for a Torque Management Knob to be loaded or saved. A number of calibrations come pre-installed with the ESP Software package. Where required, a custom calibration can be created.
From the image above:
1 – Selecting the yellow Open icon on the top left will allow the loading of a pre-configured calibration file.
2 – Selecting the blue Disk icon next to the open icon will allow the saving of your custom calibration file.
Settings Tab
Controlled Variable
This determines which RPM source to control.
Vehicle Speed Driveshaft RPM Sensor
Limits engine torque in order to control Driveshaft RPM.
Engine RPM
Limits engine torque in order to control Engine RPM.
Vehicle Speed Driveshaft RPM Sensor and Engine RPM
Limits engine torque in order to control both Driveshaft RPM and Engine RPM.
Note that when controlling both Engine RPM and Driveshaft RPM:
The largest of the two percentage cut values will be applied
The sum of the two ignition corrections will be applied
Cut Method
This determines which type of cylinder cut to implement in order to limit engine torque when the controlled variable exceeds it’s target too much for ignition retarding to control by itself. This will activate a Percentage Cut table in the ECU Navigator.
None
No cut will be applied, only ignition retard.
Ignition
Ignition Outputs will be cut to limit engine torque. This is the more common method.
Injection
Injection Outputs will be cut to limit engine torque. This is not available on a VMS-T
Ignition and Injection
Ignition Outputs and Injection Outputs will be cut to limit torque
Height Ignition Correction Enable
This setting enables Height Ignition Correction table. This table is intended to retard ignition timing if the front wheels are lifting off the ground, based on the input data received from Shock Travel or Ride Height sensors.
Setting up Tables
Timed IgnCorr (Timed Ignition Correction)
Under ECU Navigator>Torque Management select Timed IgnCorr
Axis selection and changing values
This table is intended to be used with the Race Time set as the first/x (left to right) axis and Torque Management Knob as the second/y (bottom to top) axis, though these axes are user configurable to use any ECU channel. Changing the axis values can be accomplished by pressing F3 when the table is selected, then either editing an existing value or adding a new value. Note that if you edit an axis site value, the overall table values will be adjusted so that the shape of the table is unchanged.
Tuning
The purpose of this table is so the traction tuner can tell the ECU how much to retard ignition timing, based on the time since the start of the race. This allows the car to leave the start line with full engine power and get "on-top" of the tire, then retard the ignition timing to prevent wheel-spin. The map would then re-introduce the ignition timing as road speed increased, as long as the tire can handle the extra power. This helps to prevent the wheel spin before it happens. As a general rule, this table should be tuned so that the feedback system only has to make minor corrections. This is accomplished by adjusting this table close to the logged values for the ”Torque Management Combined Ignition Correction” channel, synchronised to Race Time.
The example above shows what this table should roughly look like. (If you wish to remove the coloured columns from the 2D view (second one): Right click on the ”2D” display and select ”Hide Columns”)
RPM Target (Driveshaft or Engine RPM Target)
Under ECU Navigator>Torque Management select DS RPM Target or Eng RPM Target
Axis selection
This table is intended to be used with the Race Time set as the first/x (left to right) axis and Torque Management Knob as the second/y (bottom to top) axis, though these axes are user configurable to use any ECU channel. Changing the axis values can be accomplished by pressing F3 when the table is selected, then either editing an existing value or adding a new value. Note that if you edit an axis site value, the overall table values will be adjusted so that the shape of the table is unchanged.
Tuning
The purpose of this table is to contain the curve of the ideal Driveshaft or Engine RPM over the course of the race. The Driveshaft RPM Target Error channel is the difference between the actual Driveshaft RPM and the Driveshaft RPM Target. The Engine RPM Target Error channel is the difference between the actual Engine RPM and the Engine RPM Target. A positive error means that the controlled variable is spinning too fast. To get a starting point for these tables, copy Driveshaft/Engine RPM data from datalogs of the car’s previous races, or by racing the car with Torque Management disabled and logging the Driveshaft RPM and/or Engine RPM. It is recommended to start by only tuning one row (e.g. Knob at position 5), then, as you get the Torque Management tuned better, you’ll want to tune the different rows for 8 different levels of track condition. E.g. Knob position 8 is best possible conditions and knob position 1 is worst possible conditions. These tables should be tuned with Driveshaft/Engine RPM values which gives the best acceleration at a given point. The example above shows what these tables should roughly look like. (If you wish to remove the coloured columns from the 2D view (second one): Right click on the ”2D” display and select ”Hide Columns”)
RPM Target Error Cut Offset
Under ECU Navigator>Torque Management select Driveshaft RPM Target Error Cut Offset or Engine RPM Target Error Cut Offset
If the Driveshaft and/or Engine RPM exceeds the "RPM Target" by this amount, the ECU will drop the engines next fuel or ignition event (Selected under Main Setup > Functions > Torque Management > Settings > Cut Method). Once the ECU has checked and verified that the Driveshaft and/or Engine RPM is in range of the ”RPM Target” by this amount, it will re-introduce engine power on the first cylinder to fire. A typical value for this table is 250RPM. This table can be a single value (e.g. 250 RPM), or have up to 2 input axes (e.g. Torque Management Knob and Driveshaft RPM or Torque Management Knob and Engine RPM).
The image above is an example what this table might look like.
RPM IgnCorr (Driveshaft or Engine RPM Target Error Ignition Correction)
Under ECU Navigator>Torque Management select DS RPM IgnCorr
This is the ignition timing correction to be applied based on the Driveshaft or Engine RPM. It is highly recommended that at least one axis of these tables is the Controlled Variable RPM. Popular choices for the other axis include: Race Time, Gear and Engine RPM. Alternatively, you can just disable the second axis. It’s important to note that Torque Management can never advance ignition timing overall, even if individual tables indicate that ignition advance is desired. An example of this is, if the timed ignition correction says to retard 4 degrees, but the RPM is below it’s target. In this case, the Target Error Ignition Correction might override the Timed Ignition Correction, but it still can’t cause an overall advance.
The image above is an example what this table might look like.
Height IgnCorr (Height Ignition Correction)
Under ECU Navigator>Torque Management select Height IgnCorr
The purpose of this table is to cause an ignition retard if the front wheels start lifting off the ground. This is partially for safety and partly to optimise grip. It is used in conjunction with Shock Travel or Ride Height sensors. The image above is an example what this table might roughly look like.
Tuning Tips
It's best if the engine is tuned as well as practical before tuning Torque Management.
Bare minimum logged channels for tuning Torque Management:
Race Time (or whatever your Torque Management tables use as their primary axis)
Driveshaft RPM
Driveshaft RPM Target
Engine RPM
Engine RPM Target
Engine Limiter Active
Torque Management Combined Ignition Correction
Recommended channels to log for tuning Torque Management:
Torque Management Knob (or whatever your Torque Management tables use as their secondary axis)
RPM
Torque Management Armed State
Torque Management Driveshaft RPM Limit
Torque Management Timed Ignition Correction
Torque Management Target Error
Torque Management Target Error Ignition Correction
Torque Management Height Ignition Correction
Helpful channels to log for drag racing:
Air Temperature
Coolant Temperature
Driveshaft RPM
Engine limiter active
Fuel Pressure
Ignition Angle
Launch Control Input state
All used Injection stage duty cycles
Manifold pressure
Oil Temperature
Oil pressure
Race Time
Throttle Position
Trigger System Errors
Wideband O2
Datalog Viewer Examples
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