Anyone wanting to test STFT (short term fuel trim) control?

Looks like the rom at least this evo 8 one i'm looking at uses two tables or a set of static values to adjust fuel trims based on what looks like a voltage offset most likely an offset from 0.51 volts.

There is also a multiplier applied or its scaling the value up to 128 as a norm can't tell just not enough time in this super quick overview.

 

well I have an evo 9, and if this doesnt apply so be it: But I have tried the closed loop control using wbo2, i am currently tuning in open loop(idles A+++++), and whatever the options are my car has cams, i can get the fuel trims perfect, but once I do that, I run out of injector mapping(fuel map botoms out at 7.4) which equates to a mid 12 afr at WOT. I dont know if its related, and Im def not the smartest tuner, but Im looking for something to some how offset my fuel map... pickin up what Im puttin down? Does this apply?

PTE 1000cc injectors, none of the predetermined fuel injector values in the thread are even close.

 

sounds like u either need up to up the latency or lower the voltage.

 

Um.. you dont think I tried that when I scalled the injectors? Regardless, my trims were within tenths of zero, and the car drove extremely well, I just ran out of fuel mapping value. If this mod can help me then I am Down!

 

No that will not apply here this is for big injectors over 1400cc having issues with the trim.

Post your scaling and latencies it sounds to me like you simply have a scaling too high and are compensating with the fuel map.

 

Just because your trims are on, doesnt always mean your injectors are scaled correctly.

 

Either way im tuning in openloop now having excellent results, and as per autocross today, and a 200 mile round trip, the issue seemes extremely benign at this point. I would love to have closed loop to operate correctly, but im also trying to lean it slightly of stoich for cruise, and a little richer at idle seems to idle very smooth. Sorry for the continuous ot folks .

There was two different pte 1000cc suggestions in the supermerge thread , one for 731cc and one for 860 both with differnt latencies.

I have awhole thread dedicated to my studder which boosted posted in, and Im positive its related with the closed loop> open loop fueling differences. I just dont know what exactly Im chasing, i have a feeling that its the closed loop portion of the fuel map needing adjustment so when it goes to open loop in that area. But I only was aaware of the adjustment there beginning the other day after I already switched to full time open loop. Still learning, but making good progress. Ill revert to the closed loop option sooner or later and rethink the strategy.. (sooner if I can ya know!)