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      12-14-2013, 04:06 PM   #90
RoBiK
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Drives: Roc R
Join Date: Oct 2013
Location: Vienna

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Multiplying CR with the boost pressure is wrong.
What you want to do is to calculate the absolute pressure inside a cylinder.
Boost pressure is the relative pressure above atmospheric pressure. So if you want to calculate absolute pressure inside a cylinder (ignoring other factors like for example volumetric efficiency or that the pressure at the cylinder intake port is lower than the pressure generated by the turbo) you need to use absolute pressure - atmospheric pressure (that is not constant) plus the boost pressure. The result of this addition can than be multiplied by the CR to get a somewhat meaningful number.

Atmospheric pressure at sea level is around 14,7 psi.
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