jdg

Answers...

1. Depends on a thousand different variables.

2. Depends on another thousand different variables.

A simple answer to a simple question with more questions added because they ARE relevant.

1. Is the engine in open or closed loop at Idle? 'cause we all know it should be open loop at WOT. Right?

2a. What is the optimal AFR at idle in any engine?
What day ends in a "y"?

2b. What is the optimal AFR at WOT in any engine?
What month ends in an "r"?

Ever heard of fuel trims? Short term, long term, how they affect both open loop, closed loop, and so on?

And that's just the extremely short, very abbreviated, simplified, cut-down version.

You ain't kidding brother.
Talking to somebody that think they know what they don't know is like talking to a person that doesn't know what they don't know.

And while I tend to agree with the O/P on this point, in this particular case, "BB2" is 100% correct, on the right track, straight up, and certainly doesn't a clown like me (without any degrees by the way) to reaffirm that.....Whereas the O/P will grow tired of the constant ridicule from peers, acquaintances, the world in general, or run out of money trying to build the next bestest biggest perpetual motion machine, and move on to building toothpick bridges for the next school science project.

__________________
99% of the questions that are "STRANGE" have a dirt simple answer...usually answered by a dirt simple search.

NISSAN GOOGLE

Is it just me, or does the majority overlook the obvious?

Somebody ate a whole bag of dumbass for breakfast.

Why do people continue to run a vehicle when a warning light comes on or starts flashing? Isn't that a clue that something is wrong and you probably should NOT drive it?
Is this whole car driving thing really freekin' brain surgery?

Here's something new for the crowd/clowns...
"A little bit of Google goes a long way!"

Ever notice the one post wonders for info on turbo'ing a GA16 are never heard from again after they figure out the cost???

And if you can read this, you don't need glasses! :)

And yes, I am diggin' it...

bristol1n4

Now we are getting somewhere.... "Ever heard of fuel trims? Short term, long term, how they affect both open loop, closed loop, and so on?"

Yes of course i have and i plan on testing this!!

"2b. What is the optimal AFR at WOT in any engine?
What month ends in an "r"?"

NO NO NO - this is a legitimate question...i think that factory settings are off and the stock Ga16De could be leaned out more to gain better MPG.


I wish more people would try to get better MPG - could solve the world fuel and pollution problems. You would be an idiot not to think about this.

jdg

Go ahead....
Lean it out.
You can lean out ANY engine out there on the road and get better gas mileage.
Each and every engine out there can be run leaner to get more MPG. Every single one of them. Some can even be reliably run as lean as around 18:1 AFR...for awhile.
But, at what cost?
Yes, the factory settings "are off" on each and every internal combustion engine out ther e produce since (I dunno...) the early 80's.....if your one and ONLY concern is fuel mileage.

__________________
99% of the questions that are "STRANGE" have a dirt simple answer...usually answered by a dirt simple search.

NISSAN GOOGLE

Is it just me, or does the majority overlook the obvious?

Somebody ate a whole bag of dumbass for breakfast.

Why do people continue to run a vehicle when a warning light comes on or starts flashing? Isn't that a clue that something is wrong and you probably should NOT drive it?
Is this whole car driving thing really freekin' brain surgery?

Here's something new for the crowd/clowns...
"A little bit of Google goes a long way!"

Ever notice the one post wonders for info on turbo'ing a GA16 are never heard from again after they figure out the cost???

And if you can read this, you don't need glasses! :)

And yes, I am diggin' it...

bristol1n4

18:1 is not optimum at all. I would never lean it out that much. My only concern is MPG, Not polluting as much and not over heating my engine. It looks like im going to have to do the test myself. Ill report my findings.

i r teh noobz

Most engines run on the rich side from the factory. If I had to guess, somewhere around 12:1 is probably being commanded at WOT (and probably 14.5:1 at hot idle and cruise), but you have no way of knowing what's actually happening without a wideband.

Be warned, adjusting the MAF will change ALL fueling. You will be changing the resistance of the MAF itself, affecting all fueling calculations (not just WOT). The ECM will use the O2 sensor data to adjust fuel trims accordingly, effectively learning itself back to where you started.

To permanently adjust fueling, you're going to need some sort of programming software to adjust the fuel tables. You need to tell it to command a leaner mix. Adjusting the MAF will only work until the ECM learns its fuel trims from O2 sensor feedback.

bristol1n4

Hot Dog! Would a SAFC permanently adjust fueling? If so what model would you suggest?

BeyondBiscuits2

The S-AFC, or any piggyback fuel controller, works essentially by interrupting the signal between the MAF and ECU. It allows you to change the input to the ECU, therefore fooling the conditions, i.e. allowing fuel adjustment whether negative or positive. In conjunction with a wideband O2 sensor, you can significantly tune your A/F ratio to a degree. The original S-AFC has 30% correction both negative and positive, and the S-AFC 2 has 50% correction. The S-AFC 2 is much harder to find at a good price due to it is no longer made by A'pexi. I bought mine on eBay years ago for $200, but I sold mine for $300+ about 2 years ago. As for permanent fix... I am not sure. I ran mine for about 2 years solid without having any issues.

P.S. the S-AFC 2 also allows you to change MAF sensors (if you so wish). Great for forced induction applications, but I see no reason why it cannot be just as excellent for hypermiler goals.

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bristol1n4

"Adjusting the MAF will only work until the ECM learns its fuel trims from O2 sensor feedback."

Sorry for beating the hell out of this but what if you trick the 02 Sensor using a EFIE?

"EFIE is EFIEs intercept the signal from your car's oxygen (O2) sensor and mass air fuel (MAF) sensor to trick the computer into running a leaner air/fuel ratio."

With the use of a EFIE, Wideband Air/Fuel Gauge and turning the screw on your MAF sensor - could you lean your car permanently?

jdg

__________________
99% of the questions that are "STRANGE" have a dirt simple answer...usually answered by a dirt simple search.

NISSAN GOOGLE

Is it just me, or does the majority overlook the obvious?

Somebody ate a whole bag of dumbass for breakfast.

Why do people continue to run a vehicle when a warning light comes on or starts flashing? Isn't that a clue that something is wrong and you probably should NOT drive it?
Is this whole car driving thing really freekin' brain surgery?

Here's something new for the crowd/clowns...
"A little bit of Google goes a long way!"

Ever notice the one post wonders for info on turbo'ing a GA16 are never heard from again after they figure out the cost???

And if you can read this, you don't need glasses! :)

And yes, I am diggin' it...

i r teh noobz

Some quick reading suggests that an "EFIE" is just a resistor in a box. Many pages that I found were poorly translated, suggesting cheap foreign design. Many also suggested that HHO doesn't work without them - "but wait, there's more!"

I suggest you find a proper tuning solution. Otherwise, just unhook the O2 and create a couple post-MAF intake leaks. It will probably work better than putting some resistors on the O2.