AUDI - How to calc SMOKE,LAMBDA 2.0TDI EDC16U31

[Junkyard Dog]

Please someone say me how to calc SMOKE and LAMBDA maps? Some maths... Thanks :)

[biela]

SMOKE:
At 3000 rpm and 2400 mbar boost --> max IQ is 58,5 mg

1896 cc/4 cyl x 0.90% ve x 2400 mbar / 1000 = 1024 mg/hub

1024 / 58,5 = 17,5 AFR

17,5 / 14,7 = 1,19 lambda

LAMBDA
At 3000 rpm and 1150 mg/hub MAF --> max Lambda is 1,30

1150 / 1,30 / 14,7 = 60,2 mg is max IQ

[DiegoStud]

The above is a good way of calculating though it isn't the most accurate.

Smoke: MAP based AFR must account for ideal gas laws and be corrected not only for VE but also air temperature (this is manifold temps post intercooler not cold intake), and humidity if you can be bothered.
This is why ASMOD functions and also air-mass based boost control routines implemented in later generations of ECUs are a little more complex than the above.
This is also why MAP based smoke limitation is not as accurate as MAF based during steady state operation.

Here's a little formula you can play with: AIR MASS =((BOOST-(6.1078*10^(7.5*TEMP/(TEMP+237.3))*HUMIDITY))*100*VOLUME/(R_CONST*(273.15+TEMP)))*VE.
BOOST in mbar
R_CONST=287.058
HUMIDITY= relative in decimal percentage eg 78%= 0.78
TEMP= in C
VOLUME in cc=1968/4= 492
VE= decimal percentage eg 90%= 0.90

MAF:
The above is correct as a straight calculation (MAF/IQ= AFR). One of the drawbacks of MAF however is inaccuracy during transient operation.
This is due to more air being drawn as boost pressure builds than the engine actually consumes. (Quite logical really as how would pressure increase?, back to gas laws, plus the volume of the intercooler, pipe expansion etc)
Seeing that a smoke map is all about transient response, what would initially appear to be the most simple means of determining AFR has an inherent flaw.

Real Lambda:
The use of a lambda sensor can directly measure the AFR... up to a point. But this is diesel not petrol so cylinder charges are not homogenous and especially not so during combustion. Therefore while global AFR ratios are useful, the real smoke generation is from localised rich areas usually close to fuel spray boundaries. So any tuning must take into account the correlation between smoke (actual PM emmisions) and lambda is not rigid.

Happy tuning.

[Junkyard Dog]

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[Junkyard Dog]

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[Junkyard Dog]

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[DiegoStud]

Awful. Just look at your maps in 3d- do they look right?
NM to IQ- why decalibrated?
Lambda- see above. Just why? Why would you want a heave in IQ as you pass 750mg/stroke of air?
Smoke MAP- same again- look at the change in IQ between 1400 and 1500rpm.
Turbo- Not bad it won't blow anything but do you really need 2385mbar to burn 35mg of fuel?
N75- combined with all the above I'm sure you will have boost spikes as it struggles to cope.

Here is a file of a 2.0TDi from some contacts working close to VW. They are a dedicated team who put in 100s of hours on this just on dyno calibration.
They got a verified 170HP and 350Nm which is only 10Hp less than you are aiming for whilst still being silky smooth, maintaining EU4 compliance including DPF, all diagnostic limiters are perfect too.

Granted they made a few changes to the head design and fitted slightly different injectors and turbo, but you might be able to compare and see the tuning philosophy they've approached with.
It is also running a Siemens PPD system rather than the usual Bosch, but the labelled files in the attached a2l will help you find the relevant maps in no time.

Once dialed in you might be able go get that extra 50Nm too.

Seriously, what you are asking is not that much beyond stock- just keep your eye on limiters and make sure you extend axes far enough.
Oh and you start to get boost creep around 180 mark due to EMP, keep your eye on it.

[Junkyard Dog]

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[Junkyard Dog]

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[Junkyard Dog]

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[Junkyard Dog]

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[DiegoStud]

PLEASE SOME ON HELP ME HOW TO CALC SMOKE MAP,LAMBDA+NM to IQ FOR 1,55bar ???

I will be glad to see maths how you doit this :)

HERE IS ORI+MAPPACK

After the posts Biela and I made already you are still asking the original question.

Have you even tried to make some calculations? Are you really interested in the maths?
Or have you just attached an ori in the hopes it will be done for you?
It's not that hard to extend an axis and extrapolate linearly.

Generally there is a sense of reciprocity expected in work effort commensurate to the help requested. This is what differentiates a forum from a Chinese takeaway.

[Junkyard Dog]

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[Junkyard Dog]

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[biela]

TORQUE:
At 1900 rpm, torque map is 410 Nm.


At 1900 rpm and 410 Nm, NM to IQ map gives 73 mg IQ.


TURBO 1:
At 1900 rpm and 73 mg IQ (more than 50 mg), Turbo map gives 2300 mbar.


1968 cc/4 cyl x 0.95% ve x 2300 mbar / 1000 = 1018 mg/hub aprox


1018 / 73 = 13,9 AFR


13,9 / 14,7 = 0,95 lambda


LAMBDA
At 1900 rpm and 1018 mg/hub MAF --> max Lambda is 1,15


Then you are limited by lambda because 0.95 is lower than 1,15.


SMOKE:
At 1900 rpm and 2600 mbar boost --> max IQ is 73 mg
But boost requested is 2300 (between 2200 and 2600), then max IQ is lower than 73 mg (but higher than 67 mg).
Because of that, you are limited by smoke also.

You can repeat this calculations for TURBO 2 to see what happens.

[Junkyard Dog]

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[mjieteq]

Here's a little formula you can play with: AIR MASS =((BOOST-(6.1078*10^(7.5*TEMP/(TEMP+237.3))*HUMIDITY))*100*VOLUME/(R_CONST*(273.15+TEMP)))*VE.
BOOST in mbar
R_CONST=287.058
HUMIDITY= relative in decimal percentage eg 78%= 0.78
TEMP= in C
VOLUME in cc=1968/4= 492
VE= decimal percentage eg 90%= 0.90



Ok, but what is unit output of this air mass computing formula.
Made compute with inputs: 2400mbar as boost, 0,9 VE, 0,78 hum, 20*C, and 1968ccm volume, but the output result is nonsens to me: 5013,10235... and what is that?! I tried to different conversions, but none of them gave me any even near to good, understandable results. I thought also about 5013,10235 is corrected volume of cyl, but it doesnt make sense to me and all next maths looks like wishful thinking and cherry picking, doesn't happy me.

[DiegoStud]

Well hello,

I suppose you are right; I omitted to include Airmass is specified in mg/stroke. Given every other unit is in metric, and this is a thread regarding EDC16 where airmass per cylinder has always been specified in mg/stroke, that ought to have been self evident.

You could use 492 instead of 1968, as it would appear I did write 1968 divided by 4 in the above quote. Or, at least now you know what the answer would be if your engine were 4 times larger.

Not my problem if it doesn't make sense beyond that, but the laws of physics still apply where I live.

[mjieteq]

Not my problem if it doesn't make sense beyond that, but the laws of physics still apply where I live.

Hehee.. of course, you are right. Was my fault. I discovered the answer of my question next day having fresh head and free time to think about it - I was tired, sorry. And moreover forgot to write it here, but maybe it's good. It might be we will help with that for someone else. Thanks for the response.