Go into the aircraft cfg file and see if there are these two sections. If they aren't there cut and paste these into the cfg file:
[piston_engine]
power_scalar=1.0
[propeller]
thrust_scalar=1.0
Change one of the scalars to = 1.1
I usually use the the propeller as the most effective, but the engine can work too. It's just that the prop thrust takes effect quicker and you get moving faster. If the AI still overrun you increase the scalar to =1.2.
The cfg effects the player aircraft but not the AI so you can get ahead of them on takeoff. Just be aware that you will now be faster than your flight, so you may need to throttle down some in flight so they can stick with you.