calculation afr....let's talk

[voglioimparare]

hi all, I was wondering kindly if someone ? can explain how to do correctly the calculation of the afr in a diesel engine..I enclose a map example

https://www.professionalchiptuning.net/alfa-brera-vt133.html POST N3.

what to take to a reference to calculate the original one? then once you have made the mod, as I reported esattamnente ( or almost) to the afr series?

I saw that on the drive type golf 7 , if you do not keep an afr similar to that of the series (17), the filter regenerates frequently, so I would like to understand if there is a real formulina to apply.


to you the word!

[voglioimparare]

anyone guys?

[sergiot]

the air flow ? in the mapping of the air lens
the flow diesel ? in axis with the same mapping
a control and tweaks to the unit? measurement
then the ratio

[Four]

the air flow ? in the mapping of the air lens
the flow diesel ? in axis with the same mapping
a control and tweaks to the unit? measurement
then the ratio

Sergio, if I'm not mistaken, the ratio of the air/quantity? diesel fuel is injected just before the prex maps...share the thought?

[sergiot]

map prex????? what?????
there is a map of afr but ? only a limiter, what was once the map of the smoke.

[voglioimparare]

the air flow ? in the mapping of the air lens
the flow diesel ? in axis with the same mapping
a control and tweaks to the unit? measurement
then the ratio

[voglioimparare]

next boys nobody's? calculate the afr??

[sergiot]

let's take an example
I read in the map limiter, the maximum torque value = 370 nm at 2000 rpm/min
I go on the map pair - diesel and 2000 rpm and 370 nm I find about 74 mm3 (interpolating between 350-68,7 and 400-83,9)
turn 74 mm3 x 0.9 = 66,6 mg
I go on the map fuel - to-air and for 2000 rpm and 74 mm3 find air 1000 mg
divide 1000 / 66,6 I find afr= 15,01

[voglioimparare]

let's take an example
I read in the map limiter, the maximum torque value = 370 nm at 2000 rpm/min
I go on the map pair - diesel and 2000 rpm and 370 nm I find about 74 mm3 (interpolating between 350-68,7 and 400-83,9)
turn 74 mm3 x 0.9 = 66,6 mg
I go on the map fuel - to-air and for 2000 rpm and 74 mm3 find air 1000 mg
divide 1000 / 66,6 I find afr= 15,01


thanks a lot! you have been exhaustive! you should be type a page of exel for velocizare the calculation... it would be the top!

[sergiot]

in the calculation I made also of over-simplification, ignoring the various thermal corrections, and atmospheric pressure that are complicated to estimate
we accept suggestions and corrections.

[voglioimparare]

let's take an example
I read in the map limiter, the maximum torque value = 370 nm at 2000 rpm/min
I go on the map pair - diesel and 2000 rpm and 370 nm I find about 74 mm3 (interpolating between 350-68,7 and 400-83,9)
turn 74 mm3 x 0.9 = 66,6 mg
I go on the map fuel - to-air and for 2000 rpm and 74 mm3 find air 1000 mg
divide 1000 / 66,6 I find afr= 15,01

I was trying to do the calculation by following your method... the map torque diesel I found it (nm to iq), but I do not understand what is the map fuel-air... thanks;)

[fabiovts88]

great explanation sergiot

[Four]

map prex????? what?????
there is a map of afr but ? only a limiter, what was once the map of the smoke.

I spoke to you of the map prex turbo...this? c'? a limiter on this map which is called the (air as a function of the diesel) and ? the one that equilibria of this relationship.
With regard to the AFR I wanted to ask if you could be more? accurate on the maps to which you refer, perhaps putting a file of the study.
Thanks

[voglioimparare]

I spoke to you of the map prex turbo...this? c'? a limiter on this map which is called the (air as a function of the diesel) and ? the one that equilibria of this relationship.
With regard to the AFR I wanted to ask if you could be more? accurate on the maps to which you refer, perhaps putting a file of the study.
Thanks


I posted a sample file on purpose, I see that you are interested in most people the thing;) by the boys we make a nice thread with a good explanation;)

[jovandj]

Map and lambda, which limits the maximum afr set. ....the diesel engine for if you're skinny or excess air, and not ingrassabile....let me explain the map lambda limits the maximum fuel allowed for that amount? air....as the maf reads air 800mg jot down the gas if you set lambda 1 sara 800:14.5:55mg of diesel maximum permissions that are 60 and something mm3....but this is when you throw down the gas...jel working "split" the engine aspirera however, 700 of the air injecting 20mm3 of diesel fuel, depending on the request of the pedal, inevitably, in the lambda sara lean and very

[voglioimparare]

Map and lambda, which limits the maximum afr set. ....the diesel engine for if you're skinny or excess air, and not ingrassabile....let me explain the map lambda limits the maximum fuel allowed for that amount? air....as the maf reads air 800mg jot down the gas if you set lambda 1 sara 800:14.5:55mg of diesel maximum permissions that are 60 and something mm3....but this is when you throw down the gas...jel working "split" the engine aspirera however, 700 of the air injecting 20mm3 of diesel fuel, depending on the request of the pedal, inevitably, in the lambda sara lean and very


thanks also to you for your explanation!!


someone wants to make an example on the file that I posted as an example?? so we clearly see all how to do it? graziee;)

[sergiot]

Again the previous calculation on the point of maximum torque at full throttle and the file brera that you have indicated.
I read the point of max torque on the map limiter: 454 nm at 2000 rpm at the address 1CBD5A
I go in the map pair-diesel and I try to 454 nm and 2000 rpm and the diesel required a 75.2 mg to address 1CDD22
I go in the map fuel-to-air and looking for a 75.2 mg and 2000 rpm and the air lens 1100 mg to address 1C3226
The relationship between 1100 and 75,2 = 14,6 air/fuel ratio
not the multiplication of the oil is 0.9 why? the measures are already? all in mass
as you can see I used a simplified system without taking into account the limiter of the lambda.
but if you are working on the limiter lambda c'? need to calculate it, c' ? gi? written.

[ake85]

winols and excel, and are affixed:cool:

[sergiot]

winols and excel, and are affixed:cool:

can you explain that?
thanks

[ake85]

I want to say that if you want to learn to map, you need to know winols and use excel all here:)

[voglioimparare]

I want to say that if you want to learn to map, you need to know winols and use excel all here:)

those are points of view and habits, certainly rather than titanium winols whole life;)

[sergiot]

I started mapping in 1975 and is winols that excel had not been born yet and still winols know it but I never used it
but if you are cos? sure you don't tell me what to do with the system that you know. suggest an example.
I always learn something.

[voglioimparare]

I started mapping in 1975 and is winols that excel had not been born yet and still winols know it but I never used it
but if you are cos? sure you don't tell me what to do with the system that you know. suggest an example.
I always learn something.

sorry sergiot but are you referring to me?

[sergiot]

no ? a response to ake85 that he would have another method.

[voglioimparare]

no ? a response to ake85 that he would have another method.

[Four]

hi all, I was wondering kindly if someone ? can explain how to do correctly the calculation of the afr in a diesel engine..I enclose a map example

https://www.professionalchiptuning.net/alfa-brera-vt133.html POST N3.

what to take to a reference to calculate the original one? then once you have made the mod, as I reported esattamnente ( or almost) to the afr series?

I saw that on the drive type golf 7 , if you do not keep an afr similar to that of the series (17), the filter regenerates frequently, so I would like to understand if there is a real formulina to apply.


to you the word!
you may replace the file ori reference, why? I would not like to make mistakes...thanks

[Errecinque]

Then in the maps lambda threshold lower and the higher, if I understood well the value 1 corresponds to an afr of 14.5 that would be the threshold below which the fuel will not burn more? all and beginning to smoke, right? For? in this map, if I were to, for example, 1050 mg/hub / lambda-1 / afr 14.5 I get 72.41 that are mm3 or mg of diesel?? I have to convert or not x 0.85?

[jovandj]

14.5 and the stoichiometric not then and does not burn but it gets more fat....anyway, you can multiply by 1.19 to switch to mg of diesel fuel mm3

[jovandj]

There are about 85 86 mm3 of fuel allowed

[Errecinque]

[jovandj]

The limiter iq are in mm3 while lambda and mg, and should be converted into mm3....but if you limit by the limiter iq nn you must recalculate nnt I think

[Errecinque]

[jovandj]

See the mass of air I to the gt 80mm3 them an injection-quietly with lambda 1...I aspire 1200 mg of air

[Errecinque]

See the mass of air I to the gt 80mm3 them an injection-quietly with lambda 1...I aspire 1200 mg of air
So if I aspire pi? 1050 mg I am going to adjust the axis of the lambda. Inform the ecu of 1200, for example, cos? can I keep the lambda pi? high 1200/(80x0.85)/14.5 = 1.21, right?

[jovandj]

According to me it is not expedient to update the bp because all that air you use it only on the left wing....then you could do the same and of course you pupi allow lambda to the higher then the merit of the air in the future, but before you log in and see how much air intake is the 140 hp pero it seems to me that has a turbo slightly less than the 150 hp