Guys it isn't P factor or Torque. Torque is a twisting motion which is what causes an airplane to try to ROLL during a torque roll. The problem you are experiencing is from the Spiral Slipstream caused by your spinning propeller. Your propeller is sending a spiraling blast of air across your rudder. The spiraling air is hitting more on the left side of the rudder and less on the right. This is what makes the model turn left on take off roll. The most common correction for this is to add right thrust to the engine.
JERRY