Auto MAF (the begginning)

[kwhiteside]

Applied the AFR over 17 filter and that changed everything

I'm going to undo what I did and put that filter in.

I've had suggestions both ways as to DFCO, so unsure about that.

I'm looking in V8 BBL Pids and the only thing I see that could be clutch related is Transmision State, but I'm betting that is for Automatics anyway. That AFR over 17 did a real good job of getting rid of the clutch lean I think. When I hit the clutch, AFR goes 20+ instantly.

Joe, I saw you recommended 15 for the AFR filter. Isn't that a bit close to Stoich, could really be running a bit leaner than 15 in real world??? Either way, the filter brough all multipliers within 9.9 to 1.1, so now they are just tweaks!

DFCO yes, or DFCO no?

[WeathermanShawn]

Personally, I would disable DFCO when building a new tune. Manuals will hit that lean spike when shifting, with M6 DFCO Engaged. So to disengage, set M6 DFCO & DFCO temperature parameters to max.

You can also log the FTC Fuel Cells PIDS. You can learn a lot about fueling tracking those.

[mr.prick]

DFCO no.
Are'nt you racing, why use it?
DFCO cuts the injectors, and getting back on the throttle can give a slight hesitation.

Clutch operation can be logged with GM.STATE02
DFCO can be logged with GM.STATE05

Filters can be made for DFCO but like I said why use it?
How much fuel does DFCO really save?

[joecar]

DFCO in GM.STATE05 doesn't seem to work.

When tuning you don't really need DFCO ("How much fuel does DFCO really save?").

Yes, AFR 15.00 might be close, try then 16.00... 17.00 is fine too.

[5.7ute]

DFCO has never been a trouble to tune around if your filters are correct. Turning it off will just add a rich condition under hard decel & skew your readings the other way round. You could also add a filter removing MAP under 35kpa which will remove any data when DFCO is active.

[mr.prick]

I guess I should have tried it before suggesting it.

[joecar]

Mick has a good point... it's better to make the filter exclude boundary conditions.

[mr.prick]

You will never get data in the areas that DFCO is active tho.
I have it off and I don't have rich decel issues. (anymore)
IMO tune with it off and turn it back on later, but to each his own
Like I said "How much fuel does DFCO really save?"

[kwhiteside]

Ok guys, back on the road tomorrow.

When Checking DFCO, turns out I had the M6 temp to 286, but the other DFCO temp at 86. Maybe it was off anyways. Both at 286 now.

Settled on 16 AFR and above filter. When looking at my logs when my rpm dropped off the charts, my AFR was only going as high as 16.5 yo 17 most of the time.

Hooked up my Summit mechanical liquid fuel pressure gauge to the end of my fuel rail. Reads about 60 psi instead of the 70 my electronic one was reading, so I've verified I have stock injectors and standard stock pressure, 58 pounds as everyone reported. I guess I'll punch that into the spreadsheet to make sure my default IFR tables were set up right. I'm guessing they were right.

Looks like I've got the process going now. Slower accelleration, for good logs, filter off the high AFR's and the result will no doubt be minimal tweaks to the MAF. I'll get a few logs and flashes in over the rest of the week and move on. I'm guessing it will be time to consider LTFT's as I've heard it come up a bunch.

Ken . . .

[kwhiteside]

Made a log on the way in this morning. Not liking what I see. At low range, my maf is supposedly reporting low, but at high range it is reporting high. Now I can see it being off one way or the other, but at both ends does not compute. I moved the AFR filter in the example data below to 15.8. If I left it at 16 the lower cells pop up requesting even bigger changes. Closer I get to 15 with my afr filter, the lower end cells dissappear. Seems like a lot of cheating going on here and maybe the whole process isn't very scientific at all?

Feel free to flame away guys. I just want to trust what I'm doing a bit more.

I'll attach my log from the way in and my first iteration AutoMaf tune that it ran on.