Error in the engine speed lever

[BRONYA]

The throttle can be increased by clicking and dragging with the mouse. Although there is no visual change, both the intake pressure and RPM increase significantly, with the intake pressure exceeding 70 and the propeller RPM reaching 154%. I can even achieve 310 knots in level flight cruise.

[stelr]

Do you mean the "throttle"(MP) or are you talking about the "propeller governor handle (RPM)?"  I read where after moving the prop governor handle to its full throw (down), you can use the mouse to move it down more to achieve ~3200 RPM and >70 in of mercury manifold pressure.  Engine will overheat pretty quickly, so need to watch carb temps.

Should it even be able to achieve these settings, or is this a bug?

In either case, without doing the above, I really can't achieve speeds in excess of 250 kts in level flight.  Same with others I fly with.  That's with all cooling close, <50% fuel, and trimmed out for hands off flight.  It seems like there is some invisible drag, or hidden extra weight.  This also negatively impacts roll rate.