Ok, I noticed that for some reason my car always runs like high 13 low 14 afr when cruising.... it will maybe peak to 14.8 or 15 now and then... but it likes to stay slightly rich. Is this possibly a bad oem O2 sensor? or maybe my wideband is just off?
Is there a way to tweak closed loop fueling to compensate for this?
That's called fuel economy dude. It's exactly how the car is designed to run in closed loop.
You don't know that and your trying to do a tune? OMG....this should be interesting to watch
I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
fuel economy? running rich somehow saves gas? hmmm interesting thought....
Perhaps if i was running lean i could see where this might be for "fuel economy" but care to explain how a rich mixture is for fuel economy?
ken soggs wrote:fuel economy? running rich somehow saves gas? hmmm interesting thought....
Perhaps if i was running lean i could see where this might be for "fuel economy" but care to explain how a rich mixture is for fuel economy?
Since when is high 13's low 14's rich??
FU Tuning
ken soggs wrote:fuel economy? running rich somehow saves gas? hmmm interesting thought....
Perhaps if i was running lean i could see where this might be for "fuel economy" but care to explain how a rich mixture is for fuel economy?
Do you even know what stoichiometric is? Do you even know what the terms rich and lean signify? I think your just using terms that you've heard before. 14 is LEAN, not RICH. Get a clue before you go any further and break your car. Sheesh.
I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
The above responses from two supposedly highly informed car enthusiasts scare me.
Rich: < 14.6
Stoich: 14.6
Lean: > 14.6
Air to fuel ratio is just that. 14.6 parts air per 1 part fuel. If there is more air, thus raising the number to 15-16 or so, that is considered lean. If there is less air, and thus more fuel than stoichiometric, that would be rich.
Ken Soggs's concern is that he is staying on the rich side of stoichiometric at cruise, rather than an even fluctuation +/- a certain amount from 14.6.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Hypsy (TRU TurboSport Cav) wrote:Do you even know what stoichiometric is? Do you even know what the terms rich and lean signify? I think your just using terms that you've heard before. 14 is LEAN, not RICH. Get a clue before you go any further and break your car. Sheesh.
I just have to laugh once more that this.
I'm sure once more people read this thread there'll be plenty of LOLs at you two.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
[ion wrote: C2]Hypsy (TRU TurboSport Cav) wrote:Do you even know what stoichiometric is? Do you even know what the terms rich and lean signify? I think your just using terms that you've heard before. 14 is LEAN, not RICH. Get a clue before you go any further and break your car. Sheesh.
I just have to laugh once more that this.
I'm sure once more people read this thread there'll be plenty of LOLs at you two.
And what exactly is wrong with it?
He is complaining that 14s and 15s are rich. They are not. That is most definitely on the lean side. Yes I know that 14.6 is stoich but that is lean for his purposes. High 13s might be "rich" but it is definitely just part of the normal swing from a O2 sensor.
Just trying to not have to post a long detailed explanation. Looks like I might have to for you though....
Your O2 sensor reads one thing, oxygen content of the exhaust. That's it. To make corrections takes a small amount of time. This is why you will see swings from mid to high 13s all the way to 15s and 16s. That is NORMAL. To be technical mid 13s could be called rich, but since your using a AFR of around 11 or 12:1 for power making, for your cruising purposes it is lean. As long as it is not sitting there for a long period you are fine.
Is that better for you ion?
I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
Hypsy (TRU TurboSport Cav) wrote:
And what exactly is wrong with it?
You try to make him out to be a fool when he says high 13s-low 14s at cruise are richer than normal, and then you tell him 14 is LEAN.
Hypsy (TRU TurboSport Cav) wrote:
He is complaining that 14s and 15s are rich. They are not. That is most definitely on the lean side. Yes I know that 14.6 is stoich but that is lean for his purposes. High 13s might be "rich" but it is definitely just part of the normal swing from a O2 sensor.
No, he is complaining that high 13s to low 14s are rich for cruising conditions. That is definitely on the RICH side of stoichiometric. Mathematically, automotive-ly; you can't sit there and tell me it's lean.
Hypsy (TRU TurboSport Cav) wrote:Just trying to not have to post a long detailed explanation. Looks like I might have to for you though....
Your O2 sensor reads one thing, oxygen content of the exhaust. That's it. To make corrections takes a small amount of time. This is why you will see swings from mid to high 13s all the way to 15s and 16s. That is NORMAL. To be technical mid 13s could be called rich, but since your using a AFR of around 11 or 12:1 for power making, for your cruising purposes it is lean. As long as it is not sitting there for a long period you are fine.
Is that better for you ion?
No. Thank you Captain Obvious. You think I nor Ken Soggs don't know this?
You SAID:
Hypsy (TRU TurboSport Cav wrote:Do you even know what stoichiometric is? Do you even know what the terms rich and lean signify? I think your just using terms that you've heard before. 14 is LEAN, not RICH. Get a clue before you go any further and break your car. Sheesh.
What the @!#$ was that all about? You told him running high 13s and low 14s is for fuel economy. He questioned that, and could understand that under normal lean cruise situations the AFR should be high 14s to high 15s or low 16s. Then you come at him with the above quote as if he were a @!#$ dumbass for thinking that a 13:1 AFR was richer than 14.6!
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
He said it was BOUNCING from mid 13s to 15s. That's what the @!#$ O2 does for
fuel economy. Just because it sits at 13.8 or 14.0 for a little time does not make it rich, per say, it just makes it slightly richer than stoichiometric. 12:1 or 11:1 is rich. 13.8:1 is @!#$ fine and/or lean.
Just because the AFR goes to the rich side of stoich doesn't mean it's running rich. That was what I was driving at. His original post made it seem like he had no clue what was going on with his car, and I replied as such.
NowThenHaveANiceDayPleaseDriveThrough
I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
Hypsy (TRU TurboSport Cav) wrote:He said it was BOUNCING from mid 13s to 15s. That's what the @!#$ O2 does for fuel economy. Just because it sits at 13.8 or 14.0 for a little time does not make it rich, per say, it just makes it slightly richer than stoichiometric. 12:1 or 11:1 is rich. 13.8:1 is @!#$ fine and/or lean.
Just because the AFR goes to the rich side of stoich doesn't mean it's running rich. That was what I was driving at. His original post made it seem like he had no clue what was going on with his car, and I replied as such.
NowThenHaveANiceDayPleaseDriveThrough
Dude, why are you being an ass? I don't see anything wrong with his question. He is concerned about running "rich" at cruise.
Ken I think your problem might be related to injector constant. If it is too far off the computer will have trouble correcting AFR in closed loop.
___________________________________________________________________
Mitsu TD06-20g |3" Turbo-back Exhaust | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | Team Green LSD | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
ken soggs wrote:Ok, I noticed that for some reason my car always runs like high 13 low 14 afr when cruising.... it will maybe peak to 14.8 or 15 now and then... but it likes to stay slightly rich.
I am quite aware that closed loop fluctuates. But it is intended to swing evenly on both sides of 14.6. My point was that it rarely ever goes leaner than 14.6, it bounces around all the time, but spends 90% of the time richer than 14.6.
I ask about this because this is a daily driver, and i spend 99% of my time and gas in closed loop. i just drive 1300 miles this week alone at freeway cruise speeds. So you cant tell me i wouldnt get better gas milage if i was running .5 leaner on average. at one point my car bounced evenly on either side, now it much prefers the richer side. i would rather it be slightly lean at cruise.
Hypsy (TRU TurboSport Cav) wrote:
He is complaining that 14s and 15s are rich. They are not. That is most definitely on the lean side. Yes I know that 14.6 is stoich but that is lean for his purposes. High 13s might be "rich" but it is definitely just part of the normal swing from a O2 sensor.
I never once said anything about 14-15 being rich. I said that at cruise my car runs slightly rich. meaning the swing much favors the rich side. i RARELY even see it hit 15. 14.8 now and then... but the vast majority of the time it is from 13-14.5 Yeah that is LEAN for WOT and PE... but that is rich for cruise.
i ask this for the purpose of fuel economy.
BlackEco wrote:
Ken I think your problem might be related to injector constant. If it is too far off the computer will have trouble correcting AFR in closed loop.
I am currently still running the GMPP SC kit injectors, and have never touched my injector constant. I have some 440cc injectors i may drop in soon, but for now i am still setup with the GM reflash and SC injectors.
I was thinking that maybe my stock O2 sensor was just wearing out... they say you are supposed to replace them like every 60k or so... mine has 100k on it right now. just thought maybe it was getting tired and just begining to skew the readings on the rich side.
they always say that replacing O2 helps MPG... so that makes me think bad O2's must cause MORE gas to be used, which would mean a richer mixture... which is what i am seeing. Thus my original question.. "is one of my O2 sensors off? and can i adjust for this?" or should i just replace my oem and see if it helps.
My car rarely see's 15's either, but still get AWESOME gas mileage. It usually runs from 14.8 to low 14's. This is not something I would be too concerned with it was me.
FU Tuning
ken soggs wrote:But it is intended to swing evenly on both sides of 14.6.
I don't know where you got that information but it is false. The AFR fluctuates way too fast for the computer to be perfectly precise like that. It will go all sorts of random amounts above and below.
Edited 1 time(s). Last edited Sunday, October 26, 2008 6:43 AM
I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
woah woah 14's and 15's? are we talking about wide band readings or m45 1/4 mile times LOL
Edited 1 time(s). Last edited Sunday, October 26, 2008 6:49 AM
Low RPM VE tuning, getting the AFR commanded (14.6) to have as little error as possible, should help this. I'm doing this today for the same reason.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
SweetnessGT wrote:Keep in mind ken your tune is way out now since your engine flows a lot differently than the GMSC tune is meant for.
Also if you care about fuel economy, do what GM screwed up. Fix the DFCO settings and get them working right for you. After getting my DFCO functioning perfectly this summer I went from 18mpg to 26mpg. It's unreal how much fuel you can waste coming to a stop if you don't have that fuel cutoff doing its job.
-Chris-
Don't mean to thread jack - but could you elaborate? It was pretty much chinese to me so in a little more laymans terms would be nice. My car is currently getting terrible gas milage like 12MPG or so - I dont have a air:fuel guage so I don't know what thats running at - but I was thinking maybe injectors, or O2 sensor, then I was thinking maybe it doesn't go into closed loop...but I have no idea how to tell...all just hypotheses.
sweetness what sort of changes did you make to the DCFO?
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Rodimus Prime wrote:sweetness what sort of changes did you make to the DCFO?
also apologize for thread jacking, but i am interested in this as well. i have mine set at these numbers: enable rpm: 1475, disable 1375, enable map: 10, disable map: 12, enable vss: 14mph, disable: 12mph. (fake 2.5 bar tune, so that is why i put 10kpa and 12kpa).
oh btw ken, the injector constant im using for the 36# injectors is 0.27000 and it seems to work.. i might play around with that but thats what im tuning with so far. not sure if the difference in our setups would affect it by a lot or not, but thats what im using
12.33 @ 111.67 mph [Oct 2009]
Dyno'd on 08/02/09 - Mustang Dyno:
327.6 WHP 333.6 WTQ [10.1 AFR]
what does/ how does the fake 2.5bar tune work for the eco exactly?
I think the discussion is good, but advice for the 2.4 generally doesn't apply to the ecotec.. they have speed density whereas we do not.
DaFlyinSkwir(LS61) /PJ/ OEM+ wrote:what does/ how does the fake 2.5bar tune work for the eco exactly?
I think the discussion is good, but advice for the 2.4 generally doesn't apply to the ecotec.. they have speed density whereas we do not.
it gives you timing control under boost. it splits your spark map readings somehow so you go beyond 105+ kpas
unless your running high boost it is a waste of effort.. has no fueling affect making it just more difficult to work with hpt.
and to me it is useless on a blower set up since they are so consistent.
K. Vega..Mr. M62 L61 himself. wrote:DaFlyinSkwir(LS61) /PJ/ OEM+ wrote:what does/ how does the fake 2.5bar tune work for the eco exactly?
I think the discussion is good, but advice for the 2.4 generally doesn't apply to the ecotec.. they have speed density whereas we do not.
it gives you timing control under boost. it splits your spark map readings somehow so you go beyond 105+ kpas
unless your running high boost it is a waste of effort.. has no fueling affect making it just more difficult to work with hpt.
and to me it is useless on a blower set up since they are so consistent.
if the 1bar is maxed out, how would faking a 2.5bar change anything other than reduce your resolution?
why not just use the last two columns (100kpa and 105kpa) to set your ignition advance for boost? In theory, when the sensor is maxed out, it can't tell the computer anything different anyway. It'll only see 105kpa. Can't you just set the curve you want in the last columns and leave it alone? does timing really fluctuate that much? whats the boost curve of the M62 vs rpm look like?
yea you can, thats what I used. I don't know why people insist on using this fake 2 bar. 100 and 105 are enough to control timing.
My timing increased all the way to redline back on the dyno and back when I was running the intercooler it would be making just over 20 degrees of timing near redline.
