Balls to the wall is a slang expression for giving maximum effort, or travelling in maximum speed, similar to full throttle, originating from the same context.
The phrase stems from aviation, where the throttle levers usually ended with round ball-shaped tops, which had to be pushed up against the firewall in order to reach full throttle, hence pilots’ jargon referred to this motion as “balls to the wall”.
The phrase would appear in slang during the 1960’s.
During the 1970’s, the expression would spread in the United States and appear in Great Britain as well as other countries in the Anglophone world.
In 1984, the German heavy metal band, Accept released their single, titled “Balls to the Wall”.
A similar expression, though from a different source is balls-out which is also related to maximum speed and effort.
“Balls to the wall” was first defined on Urban Dictionary in 2003.