Typ17 16vg60 Posted August 29, 2018 Report Share Posted August 29, 2018 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 Quote Link to comment Share on other sites More sharing options...
Typ17 16vg60 Posted August 31, 2018 Author Report Share Posted August 31, 2018 Nobody any meaning? Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 31, 2018 Report Share Posted August 31, 2018 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. Quote Link to comment Share on other sites More sharing options...
Typ17 16vg60 Posted September 1, 2018 Author Report Share Posted September 1, 2018 Thank you very much! The main thing I understand, but with the different pressure I was confused. Adamw thanks again for your example and your time. Quote Link to comment Share on other sites More sharing options...
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