Pop & bang is a function that creates the characteristic crackles and bangs from the exhaust when you lift off the throttle, through a software setting. It is preferred on sporty and performance-oriented vehicles.
What is pop & bang?
The crackling, popping and sometimes flame sound heard from the exhaust when the throttle is released in race cars and sports cars is called "pop & bang". On a normal vehicle this is an unwanted combustion behaviour, but when created in a controlled way through software it becomes a sound effect that defines the car's character.
How does it happen?
Normally fuel is cut when the throttle is released. In pop & bang software, a very small amount of fuel is sent to the cylinders at that moment and the ignition advance is retarded. Because combustion cannot be completed fully in the cylinder, unburnt fuel passes into the exhaust system and ignites in the hot exhaust environment, creating the bang.
The intensity of the sound is adjusted with parameters such as fuel quantity, ignition delay, rev range and engine temperature.
Which vehicles can it be applied to?
The application depends on the ECU design and is especially common on petrol engines. The structure of the exhaust system (catalyst, silencer) directly affects the sound character. For suitability you can select your vehicle in the panel and see whether the relevant option is offered.
Things to note
- Unburnt fuel igniting in the exhaust puts thermal load on the catalyst and exhaust components
- High-intensity settings can shorten component life
- In many countries use on the road is restricted because of noise and emission regulations
- The function is usually activated depending on the driving mode or a rev/temperature condition
When creating a request
Pop & bang is requested as an option together with the main software level. In the request note, stating the sound intensity you want (light/medium/aggressive) and the vehicle's exhaust configuration helps the calibration be done correctly.
Frequently asked questions
When set correctly and moderately it generally stresses the exhaust components more than the engine itself. With overly aggressive settings component life can shorten.
Because the combustion design of diesel engines is different, this function is mainly applied on petrol engines.
Yes. In most applications the function can be tied to sport mode or to certain rev and temperature conditions.