Safc And Logger Tuning

[subie22]

Ok i just recently bought a logger to tune my car, But i know theirs a lot of info on these forums, but i cant seem to locate much that applys to my car. I am trying to find what i should be doing with it exactly, i have boost leaks to take care of. But i am just trying to learn on how to tune myself. Any leaks would be nice, i know with my low fuel trims i need to have it at 100% which it is at for 1k and 2k i just have to do 3k, and i was told past 3k that the ecu doesnt do much with the fuel trims. Just any help would be great, pardon my post. Not rele sure were i should of started..

 

[2gGSX]

I'm not really sure what you're asking, but it sounds like you're going in the right direction with fixing boost leaks and getting your fuel trims in line first. Being that you have a 1g, try to get your LTFT Lo and LTFT Hi all fairly in line before going on to WOT tuning.

I think that the 1k 2k 3k thing that you were talking about corresponds to trying to tune each of the LTFTs. An easier way to think of it is that LTFT Lo will only be changed when your raw MAF reading is around 50 hz or below, while LTFT Hi is updated at around 250 hz.

I've never messed with the pocketlogger setup so someone else should step in if they have more experience.

 

[subie22]

i am confused on the whole LTFT Hi what would i have to do exactly to tune those, i guess the it works the same way as the LTFT Lo. But theres no menu on the safc to do that is there.

 

[subie22]

But i did mess with the the low fuel trims, and the car seems to be a lot smoother, just regular driving. And it idles a lot better. But to another issue, my tps sensor when i have the car off and put the pedal to the ground it only reads, maybe 94%. Which either means, mines shot, or i have to tighten the throttle cable, or i guess you can call it setup to read correctly. Excuse my termination.. Also just to double check, you want your fuel trims close to 100% correct, But at my idle which is around 750 to 860 its at 120% or so.

 

[2gGSX]

94% is close enough, you shouldn't have a problem.

Like I said, LTFT Hi is updated at 250 hz which should be where you're at while highway cruising. Basically, it'll only update while you're above 250 hz.

 

[subie22]

So i would have to do a data log, and see where everything is at, then adjust from there?

 

[turboglenn]

^^... Yes, Idealy, that is how it works.. but it's best especially in the beggining to have a passenger to make sure to tell you to let off the gas if things go dangerously lean at any time

There's some great basic info on tuning with SAFC's on RRE's webpage... back when i had an AFC in my car i used that as a guide to learn the workings of the unit.

Go here and get the basics. Then after you're familiar with whats going on and what to change, you'll become comfortable enough to tune your car with confidence and not have to concentrate too much on fuel trims and things that are only part of the equation in the over all scheme of tuning.
http://www.roadraceengineering.com/ecltechtips.htm

the logger allows you to drive nad pay more attention to the road for safety and then go back and see where you need to make changes and what else is going on with the engine and ECU. A logger is a great too for learning as well as a necessity for the advanced tuner looking to get the most out of their combo ( and again, it keeps your eyes on the road and not over at the AFC and whatever you're using to read the other paramerters ) i know a guy who hit a parked car while looking at his AFC trying to tune while driving :

 

[subie22]

Ok well you said theres more then just fuel to tune with, so i am guessing you have to tune for knock and what other stuff.

 

[subie22]

I have noticed at idle my O2 voltage is around 2.5v i beleive that seems a lil to high at idle, shouldnt it be around .98 simething of that nature, unless i am getting that confused with something else.

 

[turboglenn]

Yes, that's weird seeing how anything other than a 5 wire wideband o2 should not read anything above 1 volt. But i od remember seeing that on a local cops car that he brought to me to look at. it turned out the thing was wired in wrong. Sorry to say that was so many years ago i forget what it was that was hooked to the worng wire.

Also, at idle the car should be running in closed loop and constantly cycling between .2 and .8 volts up and donw constantly. That's how it keeps it as close to 14.7:1 (af ratio) as possible.

And what i meant is there's more than just FUEL TRIMS to tune to, Meaning things like A/F ratio, and drivability. Well, i'm tired as hell and probably maing less and less sense as my medication is taking effect. i'll get back on helping out tomorrow. G'night all.

 

[subie22]

well maybe i am looking at something else with those values?

 

[subie22]

i no my buddy was trying to help me, and he wanted to wire my narrow band o2 sensor, maybe thats the cause of it. And to let you know its pinned in the greeen, And from what i know, it should be reading something not rich, since my lo fuel trims seem to be where they need to be. Also i am aiming for 100% for my lo idle fuel trim, correct me if i am wrong, I guess 2g guys aim for 0% and us 1g people aim for 100%:?

 

[turboglenn]

How may things are sharing the otuput from teh narrow band o2? i've seen od readings when people have an AFC, the stock ECU and an FC all reading from teh same sensor. I'm no electrical engineer, but i think it causes some sort of electrical bleeding or signal interference..

I'm stumped and passing out for real this time

Good night and good luck with the car..get some rest and dig into it tomorrow

 

[2gGSX]

i no my buddy was trying to help me, and he wanted to wire my narrow band o2 sensor, maybe thats the cause of it. And to let you know its pinned in the greeen, And from what i know, it should be reading something not rich, since my lo fuel trims seem to be where they need to be. Also i am aiming for 100% for my lo idle fuel trim, correct me if i am wrong, I guess 2g guys aim for 0% and us 1g people aim for 100%:?

What exactly did you guys wire into where? It sounds like you just said you guys re-wired the stock narrowband O2 sensor? Where to/why?

 

[subie22]

No we were just trying to get it to work, but we figured at the time the car was running insanly rich, so we figured that was the case. But now that i have messed with the fuel trims at idle that shouldnt be the case.

 

[subie22]

Now my car idles, kinda high kinda back to the way it was, so i don't know if the car was just cold when it was idling, but i had a good idle going on, around 750-860 but now its up around 1200 or so, what does this mean, could my fuel trims be back to the way they were. When i did the lo idle fuel trims it was a little bit warmer, prob close to 50 or so. So i wonder if thats it. But i know our cars has a mind of their own, also when i went to work it was fine. Maybe it wasnt completely warmed up.