[Gmecm] $58 VE tuning approach

[Rob Handley]

Sanity check required:

Given that:

- total VE = VE1 + VE2, where VE1 comes from either F29 (open throttle) or 
F29E (closed throttle) and VE2 comes from F30
- F29 runs out at 4000 RPM, and at higher RPM than that VE1 = the relevant 
MAP indexed value in the 4000 RPM row of F29
- all the cells in F29, F29E, and F30 can hold any value from 0 to 100% VE 
(i.e. the full range)

...and assuming that:

- the engine VE is no less than 30% at any RPM and MAP
- the engine VE at 6400 RPM is no more than 30% less than the VE at 4000 
RPM:

...can anybody see a problem if I:

1) start my VE tuning by putting 0% in all the F29 cells and 30% in all the 
F30 cells (therefore VE = 0 + 30 for all RPM and MAP to start with);
2) then tune up F29 (considering the open throttle case) for 0 to 4000 RPM - 
so VE = VE1 + 30 (N.B. I was thinking of changing the code so that F29E 
isn't used anyway);
3) then finally tune the 4400 RPM to 6400 RPM (inclusive) values in F30 to 
apply corrections to the 4000 RPM F29 VE for these higher RPM.

I must say it seems a bit naff that GM appear to have constructed the VE 
look ups based on the assumption that the profile of engine VE as a function 
of MAP does not change above 4000, rather than preservng the full 2 axis 
lookup right up to 6400.

Taking the F29E disabling idea further, I'm tempted to change the code so 
that the F29E memory locations are used to extend F29 to provide 4400, 4800, 
5200, 5600, 6000, and 6400 RPM rows - which would give greater flexibility 
to optimise the VE tuning in this band than the standard set up.

Thoughts anyone?

Robin