What is RPM/MAP MAP Correction used for?

[wazzu70]

What is this map supposed to be used for? Are the values in the table a scalar to fine tune the MAP readings? Does the table allow you to modify VE or ignition by the specified amount when the axis conditions are met?

Always been curious about this but I am sure I don't need it for anything :)

[Erikk]

You use it to adjust the boost compensation when using Alpha-N (TPSvsRPM Ve-table)

[wazzu70]

Thats what I figured. So it only impacts fuel (VE) and not timing?

[gunni]

Yes.

[wazzu70]

Good to know.

Does timing requirements not vary that much by pressure, or do you use kpa on the ignition and lambda y-axis?

Just curious how this all works :)

[Erikk]

The sparktable is mostly MAP vs RPM, you can use TPS vs RPM under atmospheric pressure and automaticly switch to MAP vs RPM when the engine is building boost.

But thats usually not relevant when using Speed-density.

[wazzu70]

Thank you for the explination :)

[fphil]

You use it to adjust the boost compensation when using Alpha-N (TPSvsRPM Ve-table)

This table seems to be active also when runing Speed Density although it does not appear on the Calc Model.
Has anyone used it in this case? Per example as an extra table for fine tuning around the idle points ?

[fphil]

I am not with the genboard presently. I cannot test what I said, but I realize already that I am probably wrong. As said above it should be a way to tune the calculus of the pulse time done from RPM and MAP, thanks to a correction in % of the MAP value used internally for this calculus . This correction being function of RPM and MAP.
However, may be this table can be used to add some low map lines at the VE table about the idle rpm, useful per ex. for the return from overrun?