Which table should I be editing when trying to adjust air/fuel? Let's say I dyno 13.5 and want to get to 13.0. Haven't dynoed yet, but just for conversation sake.
Which table should I be editing when trying to adjust air/fuel? Let's say I dyno 13.5 and want to get to 13.0. Haven't dynoed yet, but just for conversation sake.
I like to keep PE at one value across the table, then I adjust the rest VIA IFR. Makes all my graphs flat as a board.
Rick
So your PE base values are all the same? What do you have them at?Originally Posted by Synergy
And then you use the injector flow rate to get the air/fuel ratio you want. Do you happen to know how the flow rate affects the air/fuel. I just wanted to know how much to vary it by so I don't grossly overdue it. Thanks.
For whats its worth:
SET NEW FUEL INJ DATA: Measure resistance at the poll. A stock LS6 for example is 17ohms. Noting 0 adj at 18v, the amperage is
18v = 17ohm * amp
amp ~= 1.05 or so.
New Fuel Inj, for example Lucas 30lb/hr = 16.4ohm resistance. Zero adjust for amp flow at
16.4ohm and 1.05mps = 17.36v at no adjustment.
Multiply the entire inj volt offset table by
17.36/18. This is the base setting for the injector.
if 14.682/PEvalue = 13.5(a/f programmed) and your wideband A/F=13.5 (wideband), your IFRs are correct.
several scenerios:
SET IDLE FUEL: decrease or increase IFRS until ~0.8% STFT idle.
SET WOT:
//air fuel is leaner than expected
if (wideband > programmed a/f)
decrease IFRs scaling through 0% change at idle
45kpa??
//air fuel req richer than expected
if (wideband < programmed a/f)
increase IFRS scaling through 0% at idle.
You must scale this evenly through idle to maintain the idle mixture and maintain good low end snap.
//desired tuning achieved when
wideband = programmed a/f.
At this point, you can use the PE table to go richer or
leaner.
ADJUST PART THROTTLE USE THE PE TABLE:
I use the o2 voltages, histogram and wideband for this.
NOTE: At idle, expect around 40-45kpa, this value is close to the center of the IFR table. Therefore, adj seen will be a result of data left of this cell.
You are too smart for me. That just went over my head.
:huh2: Agreed. I love mathematics... My table stock came with a scale in it. small to large over the course. The graph shows it to be flat. When I had mine professionally tuned, they used the same scale and multiplied it by .75
Don't know... just being observant.
Because it must be Brent!&&\'05 FORD F-250 Diesel, baby
:huh2: I didn't think it was that bad. Let me simplify:
Increase the flow rates by 1%, expect a 1% lean condition
Decrease the flow rates by 1%, expect a 1% rich condition.
Gotcha! 8)
I don't understand how decreasing the flow rate of the injectors cause a rich condition and increasing causes a lean condition. Isn't that backwards?
Eric - 01 Silverado 5.3 ECSB
ET: [email protected] 1.77 60' 5200 lbs
Crappy website about my truck
My Myspace page
Usually contains explicit material (language, etc..)
It's Peanut Butter Jelly Time!
If you DECREASE the flow rate of the injectors, the car's computer thinks it has smaller injectors installed and will
command a larger pulsewidth. A good example:
given lb/hr x 454/3600 = gm/sec
stock ls6 28lb/hr : 3.53gm/sec
lucas 30lb/hr inj : 3.78gm/sec
If you install the lucas injector without any changes to tuning, you will get 3.78gm/sec fuel flow, but the car's computer is doing calcs based on 3.53gm/sec. This will
cause an enrichment 30/28.
Ahh, thanks for the clarification.
Eric - 01 Silverado 5.3 ECSB
ET: [email protected] 1.77 60' 5200 lbs
Crappy website about my truck
My Myspace page
Usually contains explicit material (language, etc..)
It's Peanut Butter Jelly Time!