Does "100%" not means that the prop is on full fine pitch (long time I didn't play the game)? If so, pitch HAVE to be on fine pitch at start-up.
Rads have to be closed and eng run at a stable regime (low) until the temp as raised (rad closed). It take usually 3 to 5 min to do so. Then you can apply power gradually to move the plane (no chocks).
If you don't warm up your engine, you will suffer engine damage applying power too early and won't be able to get full perf out of your engine during flight.
I hve witnessed a lot a players chocking their engine on the ground in order to get-off early. Those generally also complains that they can't get the perfs as in the manual
~S