Guys, I am going to "argue" the opposite point of view
There is no way on earth that a tuner can take a FI bike and tune it correctly without air fuel ratio meters.
with dyno tuning there is only one thing that is important. Air Fuel ratio.
Once you hit the perfect ratio, HP and torque will automatically be at maximum. There is no such thing as tuning for most HP and torque. HP and torque is a direct result form a perfect combustion and that is directly related to the best possible A/F ratio.
Here is the biggest problem with guys in South Africa and maybe elsewhere in the world. The guys use a standalone lambda sensor, attached to a thick pipe that they hang behind the exhaust. The O2 sensor is in direct contact with fresh air, so the A/F reading they get is bogus (showing way leaner than what the motor actually burns). So they refer to manual tuning, and just simply ignore the A/F ratio because if they tune for 13:1, with stray O2 at the sensor, the bike runs very badly, as they normally over-fuel the bike.
If you have the correct equipment, A/F ratio is critical, and once tuned, the ratio is constant for all throttle inputs and RPM ranges. That's what you want.
Another problem guys have in SA is that the Powercommanders are way to complicated for them to tune by hand, especially without an A/F ratio. Their dyno also have no load control, so they also cannot tune partial throttle inputs. They sell TFI units to clients. TFI have no throttle input, so it is only good for full throttle and it has 4 screws to set. Easy to tune if you have 4 screws to turn, and you can do a few runs to see which setting is best, without A/F ratio. 99% of the other throttle settings are ignored and is guaranteed to be out. They give you a full throttle dyno run, riders think they got a great deal and end up with a badly tuned bike for normal riding.
There are only one ways to tune a FI bike correctly and that is:
- Use a powercommander with a dynojet dyno equipped with Tuninglink software.
- 2. Buy a PC or simmelar device with an Auto tuner on it. (note this can also be a problematic device if not installed correctly)