Emtron Custom Air Mass

Emtron Air Mass Model

Overview

The Emtron Air Mass Model provides a flexible framework for constructing a custom air mass calculation strategy using one or two independent air mass calculation methods.

Two independent calculations are available:

• Air Mass Model Calculation 1
• Air Mass Model Calculation 2

Each calculation can be configured to use one of the following air mass calculation methods:

Single Calculation Mode

If only a single air mass model is required, configure Calculation 1 as desired and set Calculation 2 to Off.

In this configuration, the ECU uses the output of Calculation 1 as the final engine air mass value.

Dual Calculation Blend Mode

For applications requiring the advantages of multiple air mass calculation methods, both Calculation 1 and Calculation 2 may be enabled simultaneously.

When both calculations are enabled, the ECU uses the Air Mass Model Blend Table to determine the contribution of each calculation to the final air mass value.

• 0.0% Blend = 100% Calculation 1
• 100.0% Blend = 100% Calculation 2
• 50.0% Blend = Equal contribution from Calculation 1 and Calculation 2

This allows the ECU to transition smoothly between two air mass calculation methods as engine operating conditions change, combining the advantages of each model over different areas of the operating range.

Speed Density + Throttle Mass Flow (TMF) Application

A common application of the Emtron Air Mass Model is blending Speed Density and Throttle Mass Flow (TMF) calculations to take advantage of the strengths of each method.

At low Pressure Ratios (PR) across the throttle body, such as idle, cruise and part-throttle operation, Throttle Mass Flow (TMF) provides superior airflow estimation due to the strong relationship between throttle pressure drop and mass flow.

As the throttle opens and the pressure ratio across the throttle approaches 1.0, the pressure drop across the throttle body becomes very small and the accuracy and sensitivity of TMF reduces. Under these conditions, Speed Density generally provides a more accurate estimation of cylinder air mass.

The Air Mass Model Blend Table can therefore be configured to:

• Use predominantly TMF at low pressure ratios.
• Progressively transition towards Speed Density as the pressure ratio approaches 1.0.
• Operate using predominantly Speed Density during high load and wide open throttle operation.

This approach combines the excellent transient response characteristics of TMF with the steady-state accuracy of Speed Density.

Click here for more information on Air Mass Blend Table

Air Mass Bank Control

Air Mass Bank Control allows the ECU to independently calculate the engine air mass for each cylinder bank.

When enabled, each bank operates as an independent air mass model and requires the appropriate sensors and inputs to support bank-specific airflow calculations.

Typical examples include:

• Independent inlet manifolds.
• Dual throttle body systems.
• Dual plenum engines.
• Engines equipped with bank specific pressure, temperature or airflow sensors.

ℹ️ Notes

1) Engines with inlet manifolds connected by a balance tube or crossover passage may not exhibit true banked airflow behaviour. Any pressure differential between the manifolds will result in airflow transfer through the balance passage, reducing the effectiveness and accuracy of independent bank air mass calculations.

2) Air Mass Bank Control is available for all Air Mass Model types.

2) Ensure the Bank Cylinder Setup table is configured correctly before enabling Bank Mode.

For more information refer to Bank Cylinder Setup.

⚠️ Important

Air Mass Bank Control is not compatible with Staged Injection operation.