The fuel or VE table is the primary method of controlling the amount of fuel that will be injected at each speed/load point.
The fuel map is a 3D, interpolated table that uses RPM and fuel load to lookup the desired VE value. The fuel load axis is determined by whether you are using Speed Density (MAP kPa) or Alpha-N (TPS) for your fuel load (See Engine_Constants)
The values in this table represent a percentage of the
Required Fuel amount that will be injected when the engine is at a given speed/load point.
Warning: Changing this value will require retuning of the fuel map!
Nofor most setups. It allows basic close loop feedback by adjust the base fuel amount according to how far away from the target AFR the engine is currently running.
Speeduino also has the ability to use a secondary fuel table which allows for blended and switched mode fueling. There are 2 blended modes and 2 switched modes available.
Blended fuel modes work in conjunction with the primary fuel table to come up with a single, combined VE. Switched fuel modes are where either the primary or secondary fuel table is used, but not both at the same time. Which table is being used at any given time can be configured based on either an external input (Eg dash switch) or set via certain conditions.
This is a blended fuel mode (ie it uses both the primary and secondary fuel tables together) that allows for different load and RPM axis to be combined. Commonly this is used for having primary and secondary fuel tables with different load sources (Eg: Primary map using TPS and secondary map using manifold pressure).
This mode is often used on engines with Individual Throttle Bodies (ITBs) to allow TPS and MAP based tables to be combined.
The final fuel value is derived from treating both values (Primary and Secondary) as percentages and multiplying them together.
This is a blended fuel mode that is very similar to the above
Multipled % mode. The only difference between the two is that instead of multiplying the values from the primary and secondary tables, the 2 are added together.
This is a less commonly used mode, but is an alternative in the same setups that you would use
Conditional switched mode will allow use of the 2nd fuel table when a certain value goes above a defined level. The available switching values are:
Dpending on the desired outcome, this can be used to expand the resolution of the main fuel table, automatically handle alternate fuels or as an alternative ITB mode (Particularly if running boosted ITBs).
Input based switch mode let's you change the fuel table that is in use via an external input to the ECU. The options required are: