Have you noticed how ‘overboost’ has become a thing when talking about extra power from turbocharged engines? But what is overboost?
In order to fully understand overboost, we need to look into turbocharger is. Turbocharger is designed to increase the amount of compressed air into an engine. A turbocharger will typically pump around eight pounds per square inch of compressed air into the engine. This means that you can generally expect to increase performance of an engine via turbocharging by around 40%.
A turbocharger uses exhaust gases to spin its turbine, the more exhaust gases you pump into the turbine, the faster it will spin.
The idea of overboost on a turbocharged engine is about getting the most amount of power out of the engine while keeping the engine safe and the emissions down.
Overboost is when the turbo runs at a higher pressure than would be safe to the engine on a constant basis – it’s safe by limiting any boost to a set time of around 10-20 seconds with the hike in power around 5% or more.
Overboost is usually an automatic response to when the vehicle is in a certain gear, at certain revs and the throttle is pinned. The idea is to provide a burst of power when the vehicle determines it is needed.