Coyote afr

[06bluchevy]

Hello I have a 2014 gt. Just curious what wide open afr should I be targeting the stock tune is commanding .83 lambda but wb02 shows as 11.8/9. I'm fairly sure the gas station I use is 100% gas may be that is throwing off this calculation. Is any power to be had leaning it out some? Side question what is ideal wot timing right now I'm logging 21/22*? Thanks for the help car is bone stock right now. tune_v2.hpt

[Russ K]

Your stoich is 14.08 and your WOT Lambda is .850. So 14.08*.850=11.968 AFR at WOT. As for the timing, you might get more power with more timing, use the scanner timer to see if more timing reduces the ET with the trans in 3rd gear from 2000-7000 RPM.

Russ Kemp

[SultanHassanMasTuning]

these engines like to run richer

[Knightwolf]

I currently have a Lund tune on mine and it seems to be around 14:1 normally, even at idle, and 11.9 at WoT...looks like that's where it's supposed to be according to this thread, except the above guy said "these engines like to run richer" Does that mean something like 11.5? Just wondering.. I haven't touched the tuning end of this yet since HpT hasn't released the software.. hopefully soon though.

[MikeOD]

You running your own wideband in there? I told my friend to wait on any more tuning with his Coyote until we can properly log the factory WBO2 sensors.

[Eric@HPTuners]

The 13/14 cars with the premium instrument clusters will display the measured AFR on the screen, but they are using 14.08 as stoich, so do not get confused with traditional wideband AFR numbers.

[PST]

When you change stoich in the tune, how does that affect the dash reading?

[Eric@HPTuners]

When you change stoich in the tune, how does that affect the dash reading?

It changes the scale. So when you go to E85, it will peg the 10.0 lower limit of the display.

[PST]

OK so the display pegs at 10, but at afr's leaner than that, it would still show afr correct for the stoich? Or does the display always assume 14.08 stoich?

[Eric@HPTuners]

OK so the display pegs at 10, but at afr's leaner than that, it would still show afr correct for the stoich? Or does the display always assume 14.08 stoich?

The display uses the stoich that is programmed in the tune. So on E85, the stoich is ~9.8, so at idle or part throttle, it would show 10.0. At WOT, you would be richer than stoich, so it would still be pegged.

If you are not using E85 and not worried about hitting that 10.0 display limit, it should read properly.

[06bluchevy]

maybe I should clarify my real question. I'm running 100% gas would I have any benefit raising my stoich and wot lambda values to match this type of fuel?

[SultanHassanMasTuning]

richer as in not the normal afr that most usually target of 12.5/12.8. best would be in the area of 12.1/11.9 from my experience.

I currently have a Lund tune on mine and it seems to be around 14:1 normally, even at idle, and 11.9 at WoT...looks like that's where it's supposed to be according to this thread, except the above guy said "these engines like to run richer" Does that mean something like 11.5? Just wondering.. I haven't touched the tuning end of this yet since HpT hasn't released the software.. hopefully soon though.

[Midnite Magic]

maybe I should clarify my real question. I'm running 100% gas would I have any benefit raising my stoich and wot lambda values to match this type of fuel?

You are talking about changing the stoich from ~14.1 for E10 to around 14.7 for gasoline with no ethanol. Might gain a little bit in fuel mileage as far as WOT lambda it would raise that as well. Might want to test on a chassis dyno and see. If it doesn't pick up power I would leave the WOT fuel alone

[06bluchevy]

Ok. Thank you. that was what I was getting at. Just was curious if anyone had done this already.

[Eric@HPTuners]

I don't see changing this value to make a difference in fuel economy. The car is going to run at stoich regardless, and at WOT its going to run the commanded lambda value. The only thing this will do is make the load calculation more correct.