Balls to the Wall
Dating back to the 1950's, this refers to nn all-out effort. The phrase originated from an aviation term. On airplanes, the throttle control handles and the fuel mixture are often topped with grips that are ball shaped, thus referring to pilots as "balls." If you push the ball forward close to the front wall of the cockpit your result would be a top speed.

We recieved an email from a site visitor concerning this idiom:
I have never heard the explanation that you gave for balls to the wall and I am a pilot. That doesn't mean it isn't true, but it doesn't sound right. My understanding is that the phrase comes from the automatic speed control for a diesel-generator such as those used on submarines. There is a hydraulic governor, which maintains the diesel at constant speed regardless of the load on the generator. Inside the governor, round counterweights are attached to a vertical drive shaft. The weights (balls) are on hinged arms. As the engine spins, the drive shaft spins and slings the balls outward toward the walls of the governor housing. The faster the engine turns, the closer the balls get to the wall, i.e., engine at high speed, balls to the wall. The ends of the arms opposite the balls were attached to a shaft, which moved a needle valve against or away from its seat, thereby controlling fuel flow. As the engine speed increases (generator load decreasing), the balls move out, forcing the needle into the seat, restricting fuel flow, and slowing the engine back down. Through various springs and other devices, this allows the engine to maintain an almost constant speed as the load on the generator changes. (来源：英语麦当劳 http://www.EnglishCN.com)

We recieved an email from another site visitor concerning this idiom:
I am a retired U.S Navy aircrew man who spent 17 years flying on Lockheed P-3 aircraft and the term we used for max speed usually on take off's is balls to the wall. Like the in the first explanation "balls to the wall" the throttles for the four engines have ball shape grips. The pilots will tell the flight engineer to set the throttle for take off, which are balls to the wall. When pushed far forward toward the fire wall is max throttle. "Balls to the Wall", is a very old saying in the U.S. Navy P-3 community