Drag Racing..... Hmmmmmmmmmm OK now we are talking..... since you operate your perticular vehicle on a flat plane of use and not in the air, you should tweek your prop use.... the pitch in excess would affect an air craft, the diameter in excess would allso affect an aircraft, however your OS 40 LA will only reach a certain RPM, thus leaning it out to the max for a race is only gonna slightly increase the revolutions....and decrease the life expectancy of the engine slightly..... a higher pitch prop will pull it farther faster with the same revolutions............. Yet just 2 more of my cents worth...... now get out there and kick some butt.......... Captain Crash.... Happy Trails