Changing the Air/Fuel targets in your tune

Initial TuneBoy Setup

This tutorial assumes that you have completed the Getting Started tutorial and have the TuneBoy and TuneEdit programs installed and communicating with the bike.

The Air/Fuel table in the Sagem ECU tells the ECU the proportions it should use when calculating how much fuel to add to the air that the motor is breating in.

Best power will be achieved with an Air/Fuel ratio of around 12.8/1.

As you can see from the following screen shot the standard maps use Air/Fuel ratios that are much leaner than 12.8/1, this is done for emission reasons and ride by noise tests.

When a tuning shop fits a PowerCommander or other fuel modifier to a bike, they will try and adjust the fueling to 13/1 using an exhaust gas probe. The result is that you have the ECU trying to get one thing and the fuel modifier adjusting to get another. This results in a system that does not adjust very well to altitude changes and air temp changes.

By adjusting the Air/Fuel targets that the ECU uses we can get the 12.8/1 required for best power without spending hours on a dyno, and will have a system that works well under all conditions.

I would suggest using a map like the following, this ranges from 12.8 at high throttle up to 13.5 at low throttle.

Once you have made the changes you should save the tune with a new file name, then download it to the bike.

If you want to go back you can download the original file.