[JDM-STI]

Originally Posted by jaygoesfast

Stupid question, but how can I tell when the car switches from closed loop to open loop ? I always assumed that high rpm @ wot was open loop, but never knew how to determine which mode it was in.

Me, myself, I cannot give you a good answer. Scott Siegel said that with your Cobb datalogging software and his Ecutek datalogging software that you can see the switch. Maybe Wolfplayer can give you a heads up on that.

[jays05]

I guess you could watch for when your short term fuel trims go to 0 (+0.39).

I'll look through some old datalogs and see if I can find any correlation.

[JDM-STI]

Originally Posted by nhluhr

I think one thing you always see when it switches to OL is that the A/F Correction (Immediate) goes to 0 and the A/F Correction (Learned) sticks at whatever it was when it switched.

Yep, that is what I gather as well from watching Scott tune my car. If you guys that are having the correction problems would, look at you MAF voltage and see what it is when the car switches to open loop. Thanks!

[jays05]

From looking at some of my datalogs, it looks like my car usually switches from closed loop to open loop at 2.5v, but occasionally it's higher up to around 2.9v.

[JDM-STI]

Man...I wish we could find a way to FORCE the car into open loop at 2.5 volts everytime like its supposed to.

[WolfPlayer]

Originally Posted by crystal_Imprezav

Also did you unmarry your AP/ST before you flashed? I don't want to comprimise losing the license of the AP by trying to change one parameter like IAT timing retard.

Sorry for the late reply. No, I did not unmarry. You can pull down your ST image, modify it, then reflash it. This will give you ProTUNER type access until Cobb releases the Advanced StreetTUNER.

t

[crystal_Imprezav]

Excellent, I just didn't want anything to 'happen' like ecutek and lose my ap license and etc. I def. need to modify my intake temp. retard b/c it is essentially making my alky injection pointless right now in the rediculous VA heat wave.

[jays05]

Interesting - this makes sense although I'm not entirely awake yet. My maps were spot on when I was running a mix of race gas and 93, the problems did seem to start when I switched back to straight 93. Some of the local gas stations say "10% Ethanol" on the pump while others don't... most likely though, they all get their gas from the same place.

My wideband died from all the leaded race gas so I won't be able to confirm this for at least a few days... I'm not touching anything on my tune till it's fixed.

edit: I probably never realized the afr change in OL because I'm spraying so much methanol in

[JDM-STI]

Very, very interesting. Anyone know how much of our fuel in the southeast contains E10? GA particularly in my case. I've been searching on the net without very many answers.

[JDM-STI]

You said in an earlier post that you car was going into open loop at 2.5 volts and sometimes 2.9 volts at the MAF. I would be interested to know if you were switching at 2.5 volts like you are supposed to on the race/93 map and your 2.9 volt occurances are happening on your straight 93 maps...
This might explain your fuel trim problems as well. I run a 93/meth map full time on my car, so it might explain some things on mine as well. I haven't had the chance to get SS's thoughts on this yet. Thanks for the info Nhluhr.

Originally Posted by jaygoesfast

Interesting - this makes sense although I'm not entirely awake yet. My maps were spot on when I was running a mix of race gas and 93, the problems did seem to start when I switched back to straight 93. Some of the local gas stations say "10% Ethanol" on the pump while others don't... most likely though, they all get their gas from the same place.

My wideband died from all the leaded race gas so I won't be able to confirm this for at least a few days... I'm not touching anything on my tune till it's fixed.

edit: I probably never realized the afr change in OL because I'm spraying so much methanol in

[jays05]

It was on straight 93+meth... basically what I did was I took a really big datalog (around 1mb as a .csv file), pulled it into excel, sorted by maf voltage, then watched where the short term fuel trims tapered off to 0. There were a handful of log entries above 2.5v MAF with a short term fuel trim not equal to zero, but the majority were at/below 2.5v. I haven't dug into it much further than that.

[JDM-STI]

What happens now if you have to fill up somewhere that doesn't have E10?

Originally Posted by nhluhr

i think i've made a breakthrough "Ah haaa!" on this topic... at least, I solved MY issue.

It all comes down to the fuel

hint: think E10

I'm guessing most of us had been tuning our cars prior to the switchover from normal gasoline to the 10% ethanol blends. They just made the switch here in Northern Virginia in late april / beginning of may. When TopSpeed was here and did a bunch of protunes, we all still had the good stuff - no ethanol.

However, that really only affects the safety of the maps in Open Loop... Thing is, the E10 fuel has a significantly lower Stoich ratio than the old gasoline. Previously we were targeting 14.7 in closed loop for stoich. E10 has a stoich point of somewhere around 14.1:1. This covers the roughly 8% change in fuel trims that I've seen in my logging.

As far as I can figure at this point (and i'm still looking into it), if you were previously targeting 11.5:1 like I was for most of your WOT mapping, you would now want to target just south of 11:1 for the E10 fuel.

Of course this means those who have severely limited fuel systems will be in a bind...

BTW - my fix for this was to simply adjust the injector scale from the stock setting of 5372 to 5427. My trims are now nearly 0 everywhere and my afr is hitting 11:1 nice and smooth.

edit - oh yeah - you should still be seeing Lambda=1 on your Widebands, but if you don't adjust the multipliers (in Logworks for LC1/LM1 users) it will still display 14.7 at stoichiometric idle, even though it's ACTUALLY richer than that.

edit2 - yes i realize there are holes and contradictions within this post, but it's late, i'm working a double shift, and i haven't had enough sleep so i'm a bit fuzzy... i'll leave it up to you guys to spot the holes for now. . .but suffice to say, don't go making any map changes solely on this information

[JDM-STI]

MAybe my situation is different than you guys. My fuel trims are perfect, at or near 0 while cruising as long as my MAF voltage stays below 2.5 volts. When you get part throttle and the MAF voltage rises my short and long term trims start a negative correction at 2.5 volts and keep making the correction until 3.0 volts when the car finally goes into open loop. No matter what we do, the car absolutly refuses to go into open loop until 3 volts.

[JDM-STI]

I thought some of the tuners would have chimed in a little more here...

[RainMaker]

I think the sad secret is that most tuners have no idea.

I've had this very conversation with tuners after they said "theres no learning in open loop"... and they were unaware of the typical integration of closed loop learning into open loop values in most modern PCMs