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remigatis
20th March, 2021, 11:01 AM
Hello , learning I want ask about stoic. passat 1.9 TDI EDC15+
If I have 71,2mg my AFR about 14 i want calculate boost.
1013/475=2.13
71,2x14=996.8
996.8x2.13=2123mbar
but my stock boost 2300
I need change this map ?
Whats mistake is biggest ?
Maybe some have info about learning ecu .
Best Regards and Thanks :)

socha1997
20th March, 2021, 11:13 AM
Use Clapeyron formule PV=mRT
Where:
- P - pressure
- V - Volume 1 cylinder
- m - air mass
- R - universal gas constant (for air about 287)
- T - temperature in Kelvin

I use this formule
m=100PV/287T
P - in millibars
V - in mililitres
T - in Kelvins


But you should take cylinder filling into account.

DiegoStud
20th March, 2021, 11:28 AM
Your mistake is thinking you can run a diesel at, or in your case below, stoichiometric.

remigatis
20th March, 2021, 03:12 PM
Use Clapeyron formule PV=mRT
Where:
- P - pressure
- V - Volume 1 cylinder
- m - air mass
- R - universal gas constant (for air about 287)
- T - temperature in Kelvin

I use this formule
m=100PV/287T
P - in millibars
V - in mililitres
T - in Kelvins


But you should take cylinder filling into account.

Where found temperature in Kelvin?

remigatis
20th March, 2021, 03:13 PM
Your mistake is thinking you can run a diesel at, or in your case below, stoichiometric.

Then how get more power ?

chrisimerk
20th March, 2021, 04:01 PM
Then how get more power ?

Let's calculate stock pd130 engine

Maf is 1051
Stock mg is 60mg
1051/60mg = 17.5 that's the stock afr

Now boost is 2350mbar stock
To work out how much boost you need for 60mg you do this.

1900/4 = 475
1013/475 = 2.13 this is your volumetric ratio of each cylinder
1013 is universal atmospheric pressure unless your really high up lol

So
2350/2.13 = 1103
1103/17.5 = 60mg

If you let's say raised boost 2550mbar which is safe boost then you will need 68mg for let's say the perfect burn.

2550/2.13 = 1197
1197/17.5 = 68mg

This is as simple as i can put it

Regards

remigatis
20th March, 2021, 06:35 PM
Let's calculate stock pd130 engine

Maf is 1051
Stock mg is 60mg
1051/60mg = 17.5 that's the stock afr

Now boost is 2350mbar stock
To work out how much boost you need for 60mg you do this.

1900/4 = 475
1013/475 = 2.13 this is your volumetric ratio of each cylinder
1013 is universal atmospheric pressure unless your really high up lol

So
2350/2.13 = 1103
1103/17.5 = 60mg

If you let's say raised boost 2550mbar which is safe boost then you will need 68mg for let's say the perfect burn.

2550/2.13 = 1197
1197/17.5 = 68mg

This is as simple as i can put it

Regards
thanks, what AFR can be smalest in diesel ?

chrisimerk
20th March, 2021, 07:06 PM
You can have it anywhere you want depending on application.

If you want smoke have it in the 14s the lower you go the more smoke and less egts,
but if you make it too rich you will loose power so it's all about finding the sweet spot for what you want,
again depending on application, drag track or just road use etc

Drag diesel cars usually have low AFR like in the 13s range to keep egts low.

Track car around 16s due to smoke regulations and more reliability due to constant use.

Road use in the 17s for more reliability and smog tests aka MOT etc

if you go in the 22s thats going really lean which I would not advise as you will have high egts usually 17.5 is the best for air and fuel mixture for diesels for normal use.

Regards

chli1976
20th March, 2021, 08:07 PM
Calculate it in this way, not 100% right, but I think it's enough

68mg x 17.5 AFR / 475 = 2.505 bar



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Klaudas1331
20th March, 2021, 08:13 PM
Best way to calculate afr and be accurate is like Chrisimerk said, this method works out fine every time

chrisimerk
20th March, 2021, 08:22 PM
Calculate it in this way, not 100% right, but I think it's enough

68mg x 17.5 AFR / 475 = 2.505 bar



Gesendet von meinem ANE-LX1 mit Tapatalk

Been doing this for over 18 years I make pd drag car tunes over 400hp with meth and nitrous all with this method it's the most accurate way
You have your way I have mine

Also it's 2.505mbar not bar
Using your way did not give me a perfect mixture unlike my method I have used every calculation there is and the way I posted is always more accurate then any other method.

Also using my calculation you get stock mg which is 60mg which is what the designers this engine calculated correct for 2350mbar using your calculations we would not get 60mg thus not correct?

Regards

remigatis
21st March, 2021, 03:53 PM
Been doing this for over 18 years I make pd drag car tunes over 400hp with meth and nitrous all with this method it's the most accurate way
You have your way I have mine

Also it's 2.505mbar not bar
Using your way did not give me a perfect mixture unlike my method I have used every calculation there is and the way I posted is always more accurate then any other method.

Also using my calculation you get stock mg which is 60mg which is what the designers this engine calculated correct for 2350mbar using your calculations we would not get 60mg thus not correct?

Regards
my maf is 1000 i want 67mg my afr = 14.9
1.9 tdi 1900/4=475 if be 2.7engine and 5 cilinder = 540?
my cilinder volume 1013/475= 2.13
So if Ihave boost 2200/2.13=1032
1032/14.9=69 mg
its ok ? thanks