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Re: BLM cell boundaries, Was: EPROM Programming



rr wrote:

> You have to watch out when changing the blm boundries. The
> '747 in particular will stop learning once outside of the blm cell
> rpm/map bounds, but will continue to do fuel corrections based
> on those cells, when outside of the boundries.


I think I see the confusion.  You don't normally go "outside" 
of the boundaries.

Say the Rpm and MAP boundaries are set at:

MAP   25, 60, 80 kPa   

RPM  1000, 1450, 2200 

These values were taken from a 747 PROM I have.



Use a non-proportional font here, to get the spacing right.


                       BLM Cell Matrix

MAP boundary   

     100 kPa---------------------------------------------
               |        |          |          |         |
               |   12   |    13    |    14    |    15   | 
               |        |          |          |         |
      80 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
               |    8   |     9    |    10    |    11   |
               |        |          |          |         |
      60 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
               |    4   |     5    |     6    |     7   |
               |        |          |          |         |
      25 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
               |    0   |     1    |     2    |     3   |
               |        |          |          |         |
       0 kPa---|--------|----------|----------|---------|
               |        |          |          |         |
RPM boundary   0       1000       1450      2200       6375



Pick a cell.  Say cell 15 for example.  To get in cell 15, 
RPM has to be over 2200, and the MAP has to be over 80 kPa.

Cell 4, has to be between 0 and 1000 RPM, and 25 to 60
kPa.

Cell 9 is between 1000 and 1450 RPM, and 60 and 80 kPa.
And so on.


If you set the last MAP boundary at 90 kPa, and then set
the "max MAP to learn" limit at 89 kPa, cells 12,13,14,15 
will always stay at 128, the neutral value.

This will you to keep from using a learned value at WOT,
if this is what you need.

This is what I was driving at.

Scot Sealander

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