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Typ17 16vg60

VE table

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Hi all, 

 

For understanding, when I got a value 90 at 200kpa and 7000rpm

And a value 85 at 220kpa and 7000rpm with the same lambda (0.79)

Then I have more power with 200kpa? 

I edit a picture. 

In higher boost I have less VE 

 

Greetings 

IMG-20180825-WA0014.jpeg

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I will give a simplified explanation to keep it short.

Volumetric efficiency as the name suggests refers to the volume of air in the cylinder, this volume is not directly related to achievable torque or power output.  The measurement that is more related to the torque output is the mass of air in the cylinder.  To get from volume to mass you need to multiply by density.

If we want to compare the example numbers that you gave above then to keep it simple we could assume charge temperature, fuel charge cooling etc and other things that affect density are constant, then we only need to consider boost.   Assuming baro was 100Kpa, then we could say a MAP of 220Kpa gives 2.2 X the density and a MAP of 200Kpa gives 2.0X.

So; 90%VE x 2.0 = 180 mass/power/torque units.   

85%VE x 2.2 = 187 mass/power/torque units.

 

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