What specific entries in the aircraft.cfg file or what record in the .air file do I need to adjust to tweak the tendency of a piston prop aircraft with a powerful engine to turn left while taxiing and during takeoff roll.  I know the torque on roll and torque on yaw entries affect the left turning tendency during flight but what about on the ground?  Editing the torque on roll and torque on yaw entries to not seem to affect the left turning tendency on the ground.  Or is that something that is hard coded in the fsx physics engine?  I am talking about the equal and opposite reaction to the torque of the engine turning the propeller that causes the body of the aircraft to want to roll in the opposite direction thus pushing the left wheel into the ground harder thus making the aircraft want to turn in the direction of the wheel that has the most traction.

It's been a minute since FSX was installed on my computer so bear with me and I may need correction....

The entries you're looking for are in the ".air" file. This binary file can be opened and edited with "Air Manager" software. 

Others will need to chime in with specific entries to help you. Also recommend fsdeveloper.com. They have an extensive archive for older simulators (and download for Air Manager).

Good hunting.

 

Okay, thanks.  I do have the aircraftairfilemanager.exe program and have used it before.  I will wait to see if someone knows which entry it is I have to adjust.

Have you tried reducing the P-factor in the FSX settings menu?

Yes, I did and it didn't help.  I found the setting I needed.  It seems it was the aerodynamic effect after all and not the planting of the left wheel harder as I had thought.  In the air file in record 1101 Primary Aerodynamics it is the entry called "(DBL) Cnr_dT Yaw Damping - Thrust."  I increased this value and got what I wanted.  I was trying to make ground steering during takeoff roll manageable.  When trying to use the rudder pedals to keep the aircraft centered during the takeoff roll if I used too little right rudder it would still turn left so if I applied a small amount more right rudder it would go too far right and want to exit the right side of the runway.  There was no in between.  It would only let me do too much or not enough.  I guess that was the effect of a digital simuation trying to replicate an analog world.  So I upped the value in the entry I described above and it worked.  The aircraft still wants to pull left but it is now manageable.  I can now find that sweet spot in right rudder input to keep it centered.