Minus Fuel Comp PW Table

[TOL]

I have an M800 with version 3 software.

Ideally I would like to create a negative/minus fuel comp table which would remove a fixed PW amount from the commanded fuel PW rather than removing a % of the commanded fuel PW.

In the nitrous section there are for example comp tables which will "add" a defined PW to a commanded pulse width.

Is it possible to create something like this but in reverse (ie: remove a fixed pulse width value from the commanded pulse width)?

The goal would be New PW = Old PW - "X" where "X" would be defined in the table. If not the current commanded PW, then at least the next.

Thanks.

[John Reed]

I have done this using one of the fuel comp tables, with one axis being FEPW and the other axis of your choosing (mine was an AUX output for a nitrous strategy). Your then set your trim % numbers so they always equal the same amount of PW. Since I was doing nitrous of course my numbers were still positive, but you can do it just as easily to the negative in the comp table.

[TOL]

Thanks John. I see, adjust the % trim to arrive at the desired net PW change. I guess that would work as long as no further fuel/cal changes were required in the field. It would be really neat to be able to use the current nitrous comp tables, but have them act as enleanment tables rather than enrichment tables for purposes other than handling nitrous chores (ie: introducing a secondary fuel). Maybe when we get to the M190 this may be possible.......

[John Reed]

Yeah I agree, I wanted to use the nitrous tables for supplementary methanol injection but I need to do enleanment and timing addition when the system goes active, neither of which the tables can do.

[Scott@FP]

If you aren't using anti-lag, could you use the anti-lag functions for enleanment/advance when you switch the supplementary inj on?

Enleanment anyways, no advance in the retard tables possible. Sorry. Maybe Z axis for load and switched via User 1 or User 2?

Noticed Mode 17 and -17 for Load Z axis is Effective PW/IJPU%, interesting.