Good Lambda/AFR for Diesel

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Re: Good Lambda/AFR for Diesel

Postby nexus665 » Wed Oct 17, 2012 8:04 pm

Hi,

thanks for all the great info! Have to digest it and then work it into the calculations for my first tune. Running on the smoke limiter then adjusting TL afterwards seems like a pretty useful idea to get a smooth torque curve.

Since I've also found widely differing AFR for "smoke free" tunes, I've wondered what the matter is - now it's becoming clearer.

Regards

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Re: Good Lambda/AFR for Diesel

Postby ecuedit » Wed Oct 17, 2012 8:15 pm

:) Yes I use that technique for extreme or fine tunes.

For every map you have to develop some kind of technique and approach
to be as best as possible and to get as finest results as possible.

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Re: Good Lambda/AFR for Diesel

Postby cstefan » Fri Oct 26, 2012 2:47 pm

can someone post a example of that technique? pics of torque limiter and smoke...

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Re: Good Lambda/AFR for Diesel

Postby nexus665 » Fri Oct 26, 2012 3:43 pm

Hi,

just set torque limiter map so high that the smoke limiter map is the lowest value - should be simple enough, or am I forgetting something?

Basically, set TL a couple of mg/stroke above the smoke map and you should be fine?

Then log actual IQ and adjust TL so it's never above that value, and then you get a smooth torque curve not limited by smoke map in normal conditions.

The smoke map and various other maps/limiters needs to be adjusted to let you inject your planned quantity, if it doesn't scale up to enough mg/stroke, but that's something else.

Regards

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Re: Good Lambda/AFR for Diesel

Postby ecuedit » Fri Oct 26, 2012 7:41 pm

Yes thats correct, you just set TL straight faar above smoke map, and let that IQ is limited by smoke map.

Than do the log in 4th gear,
write down the IQ at different RPM (at same points as on TL RPM axis)...before that you have also upper the IQ fuel temp limiter and others...
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Re: Good Lambda/AFR for Diesel

Postby cstefan » Fri Oct 26, 2012 9:14 pm

So lets supose that i calculate the smoke map from ground 0, i put the afr i want and blabla bla, then i will set the TL far above smoke values, and do the log in 4th gear then i set the tl based on these values, will be an acceptable work?

Ive done this excel sheet to calculate afr, next thing to do is to inverse the table so we can put the afr values and give us the Mg.
It would be nice if someone shares differents AFR tables..
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Re: Good Lambda/AFR for Diesel

Postby ecuedit » Fri Oct 26, 2012 9:19 pm

You will get values but lower them down -2mm3, because TL limiter should be primary one, and in different weather conditions you will be on barrier if you put exactly measured values...

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Re: Good Lambda/AFR for Diesel

Postby cstefan » Fri Oct 26, 2012 9:23 pm

different wheater condition if are you talking about air temp, we can activate multiple smoke limiters based on air or engine temperature ;)

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Re: Good Lambda/AFR for Diesel

Postby ecuedit » Fri Oct 26, 2012 10:52 pm

cstefan wrote:different wheater condition if are you talking about air temp, we can activate multiple smoke limiters based on air or engine temperature ;)


i don know the "content of your reason" for your comment, but i had in mind:

air humidity & density
atmospheric pressure
outside air temperature
intake air temperature

:)
...

for which ECU are you talking about.

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Re: Good Lambda/AFR for Diesel

Postby kinetic » Sat Oct 27, 2012 2:27 am

This method works fine for smokeless tuning, even with bad calibrated iot tables. But when tuning for max power, forget what u think u know about diesel stoich. Its amazing how much power u can make on such low lambda's. For power tuning my rule is, if u dont see smoke, there is definately more power to be had.

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