A/F ratio question....Help me out guys

Red5.0

Founding Member
Nov 12, 2000
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Brookings Oregon
Ok trying out the new chip today and I go for a WOT pass and it reads 11.9-12:1, So I think im set to race this weekend. So I turn around to head home and go WOT again now it is reading 12.5 I let off and cruise for a while then go WOT again to read 12.7:1

I dont understand why it would do this. Now Im not so sure I want to go racing this weekend. Could I get away with 12.7 with 110 octane? Any reasons you can think that would cause this condition?
 
Red5.0 said:
Ok trying out the new chip today and I go for a WOT pass and it reads 11.9-12:1, So I think im set to race this weekend. So I turn around to head home and go WOT again now it is reading 12.5 I let off and cruise for a while then go WOT again to read 12.7:1

I dont understand why it would do this. Now Im not so sure I want to go racing this weekend. Could I get away with 12.7 with 110 octane? Any reasons you can think that would cause this condition?

I would not run that afr!! one thing to remember with those air fuel ratio meters is that you need to make shure they are always powered up when the engine is running or they will fail you and give false reading once they are fouled. Also make shure you have calibrated it correctly. Then if all these things are ok check and make shure your fuel pressure is not falling off or mabie you at the end of your fuel system ?

joe
 
If the car had recently had the battery unhooked to clear the kam, then this could be the computers normal process of adaptive controll. Unless the chip burner disabled adaptive, it is normal for the a/f to change 5-10% as you drive it, depending on what type of MAF you have and which size injectors it is calibrated for. Also keep in mind that depending on your application 12.5 could be rich (na) or lean (boost) it just depends on your application. Also dont forget that the computer will adjust the target a/f ratio based on altitude, coolant temp, intake air temp, rpm, load, etc.... so depending on where you were and what you were doing, for how long, just before you got on it... these can all change which field in the fuel tables the computer looks at for target ratio.
Or it could be your wideband doesnt like your race gas, or octane booster, or any number of several other things.....
What exactly is your combo? what temp thermostat? etc....

Keep a close eye on it, and if the trend continues, talk to your tuner about it.

Good luck,
Dave-
 
ddonaca351 said:
If the car had recently had the battery unhooked to clear the kam, then this could be the computers normal process of adaptive controll. Unless the chip burner disabled adaptive, it is normal for the a/f to change 5-10% as you drive it, depending on what type of MAF you have and which size injectors it is calibrated for. Also keep in mind that depending on your application 12.5 could be rich (na) or lean (boost) it just depends on your application. Also dont forget that the computer will adjust the target a/f ratio based on altitude, coolant temp, intake air temp, rpm, load, etc.... so depending on where you were and what you were doing, for how long, just before you got on it... these can all change which field in the fuel tables the computer looks at for target ratio.
Or it could be your wideband doesnt like your race gas, or octane booster, or any number of several other things.....
What exactly is your combo? what temp thermostat? etc....

Keep a close eye on it, and if the trend continues, talk to your tuner about it.

Good luck,
Dave-


Dave , adaptive is not in the stabalized open loop fuel tables aka wide open throttle. Adaptive is drivability and idle stratagies. Just so you know

Joe
 
jsturbo03 said:
Dave , adaptive is not in the stabalized open loop fuel tables aka wide open throttle. Adaptive is drivability and idle stratagies. Just so you know
That must depend on the EEC. The ones I've had experience with still use fuel trim learned during closed loop to adjust fuel delivery during open loop. That's sorta the point :D.

Dave
 
Indeed.

Traditionally almost all PCMs with fuel trim at part throttle will take learned information and integrate it into the WOT data, albeit with a certain added fuel for power enrichment at WOT. The learning function itself does not traditionally exist at WOT, but the long term integration of part throttle data does occur.

Hence over time even the a9L will not be changed too much for too long at WOT by adjusting the fuel pressure. Part throttle data will get integrated into WOT over time.

As far as Red88's AFR changing over time, thats certainly to be expected. The important information is where the AFR settles. 12.5 is sort of in a bad limbo. A little rich for NA, for *me* about .5 to lean for SC or turbo. Also, I presume this is in 4th gear on the road. The high load of 4th will lean the car slightly compared to lower gears. Also the car will appear slightly richer on the dyno (about .3 for an SN95) due to the lighter load of a Dynojet dyno drum.

chris
 
Visceral said:
Indeed.

Traditionally almost all PCMs with fuel trim at part throttle will take learned information and integrate it into the WOT data, albeit with a certain added fuel for power enrichment at WOT. The learning function itself does not traditionally exist at WOT, but the long term integration of part throttle data does occur.

Hence over time even the a9L will not be changed too much for too long at WOT by adjusting the fuel pressure. Part throttle data will get integrated into WOT over time.

As far as Red88's AFR changing over time, thats certainly to be expected. The important information is where the AFR settles. 12.5 is sort of in a bad limbo. A little rich for NA, for *me* about .5 to lean for SC or turbo. Also, I presume this is in 4th gear on the road. The high load of 4th will lean the car slightly compared to lower gears. Also the car will appear slightly richer on the dyno (about .3 for an SN95) due to the lighter load of a Dynojet dyno drum.

chris

Small intergration you talk about is usually turned off because there is no use for it in a supercharged application. It was never designed for this application!! and his chip tuner should know that.

By the way chris thanks for paying me for the parts you purchased whatever reason you have was not communicated to me and it is not cool to just not pay :notnice:

joe
 
jsturbo03 said:
By the way chris thanks for paying me for the parts you purchased

Sorry Joe... the $46 or whatever has just slipped my mind. I'll payplay you shortly the balance. I wasnt going to try and get some of the $$$ it took to fix the parts... I just totally forgot with all the new stuff with the new job and the kid still keeping me up all night. My bad.

chris
 
Visceral said:
Sorry Joe... the $46 or whatever has just slipped my mind. I'll payplay you shortly the balance. I wasnt going to try and get some of the $$$ it took to fix the parts... I just totally forgot with all the new stuff with the new job and the kid still keeping me up all night. My bad.

chris


Okydokey.

joe
 
jsturbo03 said:
Mind your own business :nice:
I would love to, if only you would keep your personal business out of public forums. You are acting childish, and this is not the first time. I am pretty sure that your squabble with Chris has nothing to do with A/F ratio. And given that your other input to this thread was inaccurate, perhaps you could just stop altogether. :nice:

Dave
 
HairyCanary said:
I would love to, if only you would keep your personal business out of public forums. You are acting childish, and this is not the first time. I am pretty sure that your squabble with Chris has nothing to do with A/F ratio. And given that your other input to this thread was inaccurate, perhaps you could just stop altogether. :nice:

Dave

Sometimes it take a little public nudge to get some on that has not payed for months to pay as for you and your comments keep them to your self. I try and help people on this forium with thier tuning but i forgot you have more experience than me and it shows :nice:

joe
 
HairyCanary said:
And given that your other input to this thread was inaccurate, perhaps you could just stop altogether. :nice:

Dave

Dave, Dave, Dave....... Leave the tuning to Joe,.... I've seen what kind of tuning you can do from my rear view mirror. :D :D :D

Nate

p.s. Hanky owns you!! :D When's our re-match? :rolleyes: :D
 
jsturbo03 said:
Sometimes it take [sic] a little public nudge to get some on [sic] that has not payed [sic] for months to pay
Joe, you have tried your little "public nudge" trick several times. I have heard Chris' end of the story, and it sounds like you two have a bit of a disagreement. Which should get resolved PRIVATELY.

as for you and your comments keep them to your self. I try and help people on this forium [sic] with thier [sic] tuning
Spewing forth inaccurate data and proclaiming it to be fact is not helping.

but i forgot you have more experience than me and it shows
I have no idea what kind of "experience" you have, but it seems lacking. If you do not know how the EEC functions, say so. Now I understand why you recommended that I replace my EEC rather than tune it. :rolleyes:

Dave
 
Stangler said:
Dave, Dave, Dave....... Leave the tuning to Joe,.... I've seen what kind of tuning you can do from my rear view mirror. :D :D :D
I'd rather leave it to someone who has a clue :D

p.s. Hanky owns you!! :D When's our re-match? :rolleyes: :D
Anytime you want :D. But I get to use drag radials this time, and you have to stay off the juice. Remember, my car weighs like 700 lbs more than your trunk :D.

Dave
 
HairyCanary said:
Anytime you want :D. But I get to use drag radials this time, and you have to stay off the juice. Remember, my car weighs like 700 lbs more than your trunk :D.

Dave

:rlaugh:

damn man, any more excuses and you'll need a new keyboard :rolleyes:

you must be a tuning god to squeeze a whopping 280whp out of that cheap setup you've got there... :shrug:
 
WaterPog said:
you must be a tuning god to squeeze a whopping 280whp out of that cheap setup you've got there... :shrug:
It doesn't seem to be the tuning. MY air/fuel ratio is on target.

So yes, I obviously suck. But at least I have a clue about how the EEC functions. And unlike some folks, my car actually goes to the track once in awhile! :rolleyes:

Dave