To tune a CanFly® system you will need a laptop with a USB port. The data rate used on the CanFly® system is very high and a USB port connected to a USB hub will not be fast enough. Always connect the CanFly® adapter to a USB port on the Laptop. This should then run at the full USB speed and data loss should not be an issue.

Tunning is done using the CanFly® Commander which is a Microsoft® Windows application. This can be downloaded from Here.

There are two applications in the installation package:

CanFly® Commander

This is a graphical interface that allows access to the devices on a CanFly® system including the ECU's and EDU.

CanFly® Update

This application allows you to install a firmware update onto the CanFly® devices connected to the bus.

To use the utility please refer to Updating Firmware

Tuning prerequisites

This document assumes you have installed a CanFly® system as described in Installing CanFly® and the system is configured with a basic fuel map for the engine you are configuring. The engine should be running using the basic maps as provided, up to 1200 rpm.

The engine may not idle well and we don't recommend operating the engine past 1200 rpm until the AFR map is tuned.

O2 sensor

The best way to tune the system is to use an O2 sensor. While it is not recommended to use one continually with Leaded AvGas (100LL) it should work well enough while the basic tuning is done.

We recommend using the Spartan Lambda Sensor to tune the engine. These are available from many tuning shops who can also provide the Bosch O2 sesnsor.

The CanFly® Commander supports the CanID of the Spartan controller and will display the AFR on the base tuning page.

Base maps provided

The base maps provided for initial tuning are very rich, and have a fixed timing that matches the standard lycoming timing. These can be used with the mixture control and will emulate a non fuel-injected engine without any ignition advance.

The ECU's will however still retard the ignition for starting.

Safety

When tuning an engine the best mechanism is to make, or borrow a dyno mount for the engine and do all tuning on a Dynomometer. However this can be quite expensive!

Never tune your aircraft in the air. You are quite capable of causing an engine stall, or inoperable condition. While it is an annoyance on the ground it can be fatal at altitude.

Our approach is to recommend a Dyno tune, and then a comprehensive test plan that checks all operating conditions of the engine, and refinement. To do the tune without a Dyno then the best approach is to get a base map running and then use the manual mixture control to check the map while flying.

By returning the mixture to Auto the map set on the ground can be re-activated at any time.

Test Plan

We recommend the development of a comprehensive test plan before any trail flights are made. We have prepared a sample test plan that can be used as the basis for a comprehensive test plan.

Engine Data Display (EDD)

The CanFly® system can be provisioned with the Kotuku Engine Data Display that can provide all information related to the engine operation. This or an equivalent should be available in the aircraft.

Data Logger

The CanFly® Commander can perform real-time inflight data logging. The data logger in the optional EDU can store aggregate data for long flights, however the logger in the Commander will record all data. This can then be exported to analysis tools after a test run. We recommend taking a laptop on all test flights and recording all data to persistent storage for later analysis.

Engine AFR Maps

The kMag system comes with the ability to program 4 fuel injection and ignition maps. We recommend the following usage:

  1. This is map that is used when the mixture control is not between 95% and 100% and is known as the Manual map.
  2. This map can be selected by the Engine Data Unit in response to a input change. Designed for use with Nitro Injection. This is known as the Nitro map.
  3. This is the default or normal operation map and will be the default for starting. It is usually the same as the Manual map but can be tuned for climb performance and managing CHT's during climb. This is known as the Climb map.
  4. This is provided so that a Lean of Peak/Rich of Peak map can be defined. It is known as the Cruise map. This can be selected on the EDD.

Switching AFR Maps

When the ECU is powered on the default map is set to the Climb AFR Map, if the mixture control is < 95% then the Manual map is used.

Moving the Mixture lever to 100% will select the Climb map in all cases.

The Engine Data Display is used to select the Cruise map from the menu. If the EDD fails, or goes-offline the kMAG's will revert to the Climb profile as is described in the next section.

Installation where there is no EDD/EDU

In this case only the Manual and Climb maps are functional. This operates the kMAG system exactly like a manual fuel injection system and the operator of the aircraft should use the mixture control to choose the best performance at any time.

Cylinder Injector and VE Map

Each cylinder in a CanFly® installation can be individually tuned for Fuel Flow. This is the hardest part of the installation, and generally the best mechanism is to use a stock map until the aircraft has been flying for a while and sufficient EGT data is available to determine how well the cylinder(s) perform.

Injector Flow Map

A key part of the tuning is the performance of the injector under varying fuel pressures. The provided tables will give good results, based on experience. We don't recommend changing these unless a calibrated flow bench is used.

The Mechanical and electrical fuel pumps deliver fuel at around 28psi however it can change. This table allows for each injector flow rate to be set in CC/Min.

Volumetric Efficiency

All internal combustion engines function as an air-pump. Volumetric Efficiency (VE) is the measure of the actual performance of the engine against a theoretical ideal pump. CanFly® supports a different VE for each cylinder and at a variety of manifold pressures and engine RPM.

This can be tuned to add more or less fuel depending on the performance of the engine.

A typical engine will have a VE of less than 65% at idle and approaching 85% or more at full rpm. The intake, and exhaust system will directly affect the actual VE values.

In general the following is a guide:

  1. Cold air induction systems with 4 balanced intake runners will improve the VE.
  2. Larger intake throttle bodies will help, up to a limit. Larger bodies also tend to have more intake drag, so it is a diminishing return.
  3. 4 into 1 exhausts with balanced exhaust lengths will generally perform better. However this will tend to be only at a relatively narrow RPM/MAP band.
  4. A constant speed propellor will do more for the engine performance than any tuning will ever achieve.

For initial tuning we recommend using the standard tuning map and then trimming for Cruise (LOP) and Climb power settings.

Basic MAPS

Kotuku provides a set of MAPS for the following engines

They are basically the same maps and should get the engine running, and will perform similarly to a legacy fuel and ignition system.

Note that all 4 Fuel and VE maps are set identically and this discussion outlines a suggested tunning regime for the Climb and Cruise maps.