Crank angle for peak pressure value is not matching..
 

Hi,
I am simulating the compression stroke of a Diesel Engine in Fluent. when I, got the results for Pressure-Crankangle curve (P-theta curve), the peak pressure value is matching with my experimental value but, the crank angle at which the peak occur is not matching. I am not getting, why the value of crank angle for peak value pressure are not matching.
How to solve this problem??

Hi
I want to plot P-crank angle in fluent
How i can it?
Tnx