Tao Lu

Assisstant Professor
Email: taolu@ece.uvic.ca

Formula SAE cars

Interim Report

Final Report

Project Logbook

Project Introduction

Objective

           The objective of this project is to design a system to monitor and display the exhaust gas temperature (EGT) of an internal combustion engine. The system will be used by the UVic Formula SAE team to monitor the temperature of the exhaust gas with hopes that the data can give insight to the performance of the engine. It is possible that this data can result in better engine tuning and produce more horsepower.

Exhaust Gas Temperature

            The ability to measure the EGT’s of each cylinder in an internal combustion engine can provide useful data when it comes to engine tuning. The EGT can provide insight on the cylinder’s air-fuel ratio (AFR), which is an important characteristic when it comes to performance. If not enough fuel is injected into the cylinders during the combustion process, the exhaust gas will be much hotter. This is known as a “lean” air-fuel ratio. Conversely, if there is too much fuel in the combustion process, the exhaust gas will be cooler. This is known as a “rich” air fuel ratio. An air-fuel ratio that is too lean or too rich can result in loss of performance in the cylinder. Additionally, if the air-fuel ratio varies significantly between each cylinder, then the fuel injection process is not distributing fuel evenly, resulting lower performance of the engine.By monitoring EGT, the engine can be tuned in such a way to optimize engine output.

Engine Tuning

When tuning the engine we monitor the engine using a Dynamometer (dyno). The combination of the dyno and the car’s Engine Control Unit (ECU) allows us to monitor several engine characteristics simultaneously. The ECU used is called Megasquirt3 (MS3) and will be briefly described later in this report. The characteristics observed are gathered from various sensors throughout the vehicle and output to a Software platform offered by Megasquirt3 (MS3). During one engine test we can simultaneously observe the following vs time:

• Manifold Air Temperature (MAT)
• Manifold Air Pressure (MAP)
• Coolant Temperature (CLT)
• Throttle Position (TPS)
• Air to Fuel Ratio (AFR)
• Revolutions Per Minute (RPM)
• Horsepower (HP)
• Torque (TRQ)

Each of these characteristics provides insight into how the engine is performing. With this data we can tune the engine with the MS3. There are 3 things we can adjust:

• Spark Timing,
• Injector Timing
• Volumetric Efficiency (Volumetric efficiency is a ratio of the quantity of fuel and air mixture that enters a cylinder during the intake stroke to the actual capacity of the cylinder in static conditions.)

It is our hope that by adding EGT to the list of measurable characteristics, the engine can be tuned even more effectively then it already is.

 

EGT Monitoring System

In order to achieve effective EGT monitoring, our system will need to consist of:

1. Temperature sensors to be placed in the exhaust manifold.
2. Signal amplifier used to amplify the analog temperature signal
3. Data logging/displaying system to display the data.

There are several factors to consider with each of these components.

 

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