035 PIEZO INJECTION

Porsche has used Piezo injection for the new 992, but what exactly is it?

Porsche has sought to make the 992 not only the fastest but also the most efficient 911 generation of all time. It’s employed many tactics and technologies to do this, one of which is the use of Piezo injectors with its direct fuel injection (DFI) system.

Porsche has experience with Piezo injectors, using them on its diesel Cayenne models of the past. Now though, the clever science behind them has been applied to a Porsche petrol engine. It works like this: Piezoelectric substances are able to convert mechanical signals (such as sound waves) into electric signals, and vice versa. It’s for this reason these substances are widely used in microphones and earphones, but also to generate a spark for igniting gas, and this is where cars and Porsche comes into the equation.

Piezo electric crystals change shape when a voltage is applied to them: when a positive current is applied, the crystals expand, when the current is negative, the crystals retract in size. This is done within thousandths of a second each time. These movements open and close injection valves, which helps trigger the main jet needle.

These valves open and close much faster than a conventional, solenoid injector as used up to the 992, allowing greater precision of the injection, the accuracy gained here leading to better atomisation of the fuel. This method also provides feedback to the main computer system, as it can accurately monitor each individual firing of each injector, so if one firing is lean, this can be made up on the second firing, meaning therefore the system is incredibly efficient, consistent, and powerful.

The use of Piezo injectors is another example of how the internal combustion engine continues to further improve on its efficiencies, allowing us the ability to enjoy our modern Porsches – powered by emotive petrol engines – responsibly.