balls to the wall

Meaning

Adverb

• Full throttle; (at) maximum speed.
• (With) maximum effort or commitment.

Origin

• "Balls to the wall" was probably first attested to in the 1960s in the context of aviation. Aircraft have up to three controls per power-plant: throttle control; mixture control, in aircraft with reciprocating power plants; and propeller RPM control, in aircraft with a variable-pitch propeller. These controls can be either plungers that you push the ball end into the firewall for maximum power setting, or a lever with a ball top that you push upwards towards the firewall for maximum power setting. Thus, putting "balls to the wall" gives the aircraft the maximum power output for takeoff. It probably does not originate from railroad jargon as some have previously claimed (and if that is correct then it is not directly analogous to the adjective balls-out).