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Calibrate, Validate, and Optimize SI Engine with Dynamometer Test Harness

The spark-ignition (SI) engine dynamometer reference application represents an SI engine plant and controller connected to an AC dynamometer with a tailpipe emission analyzer. Using the reference application, you can calibrate, validate, and optimize the engine controller and plant model parameters before integrating the engine with the vehicle model. To create and open a working copy of the SI engine dynamometer reference application project, enter

By default, the reference application is configured with a 1.5–L SI dynamic engine.

You can configure the reference application project for different dynamometer control modes. To implement the operating modes, the reference application uses variant subsystems.

This table summarizes the dynamometer tests.

TestObjectiveMethodSI Engine Variant

Execute Engine Mapping Experiment

Assess engine torque, fuel flow, and emission performance results using an existing engine controller calibration.

Dynamometer controller commands a series of engine speeds and torques to the engine controller. At each quasi-steady-state operating point, the experiment records the engine plant model output and the controller commands for the current calibration parameters.

Recalibrate Controller

Match measured engine torque to commanded engine torque across engine operating range.

Dynamometer controller generates a feedforward throttle table by matching the measured engine torque to the commanded engine torque across the engine operating range.


Resize Engine and Recalibrate Controller

Match engine torque to desired engine power and number of cylinders.

Dynamometer resizes the dynamic engine and engine calibration parameters. Also, the dynamometer recalibrates the controller and mapped engine model to match the resized dynamic engine.

For an example, see Resize the SI Engine.

Engine System

The reference application includes variant subsystems for mapped (steady-state) and dynamic turbocharged 1.5–L SI engine. Using the SI engine project template, you can create your own SI engine variants.

ObjectiveEngine Variant

Dynamic analysis, including manifold and turbocharger dynamics


Faster execution



SiEngineCore.slx contains the engine intake system, exhaust system, core engine, and turbocharger subsystems.


SiMappedEngine.slx uses the Mapped SI Engine block to look up power, air mass flow, fuel flow, exhaust temperature, efficiency, and emission performance as functions of engine speed and commanded torque.

Performance Monitor

The reference application contains a Performance Monitor block that you can use to plot steady-state and dynamic results. You can plot:

  • Steady-state results as a function of one or two variables.

  • Dynamic results using the Simulation Data Inspector.

See Also

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