PowerPulse: Technology that helps eliminate turbo lag

Power pulse
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PowerPulse is a technology that helps eliminate the slow onset of power typical for turbocharged engines.

The slow onset of power, the so-called turbo lag, is a problem with many turbocharged engines. What is it really about, and what is turbo lag?

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What is turbo lag?

Turbo lag is the delay between the moment you press the accelerator pedal and the moment the turbocharger begins to provide additional power to the turbocharged engine. It is time that the exhaust system and the turbocharger must create the required impulse to increase the power.

The reason is simple - exhaust gases drive the turbocharger, and until the engine gets up to speed, it has nothing to drive it. Superchargers do not have this problem, because they are driven directly by the engine, and the response to the gas is, therefore, immediate.

There are several solutions to combat turbo lag, but Volvo went about it in its way and thus developed the PowerPulse technology. PowerPulse technology was introduced in 2015 in the Volvo S90 and XC90 with the most powerful diesel engine with a volume of 2.0 and a power of 173 kW.

How does PowerPulse technology work?

The engine using PowerPulse technology is equipped with an electrically driven compressor, which fills the two-liter pressure tank with compressed air from the intake when full engine power is not required.

This pressure tank stores air under a pressure of 12 bar and, if necessary, discharges the collected compressed air into the exhaust section in front of the turbocharger.

Although the air supply is only sufficient for a tenth of a second, it is enough time for the turbocharger to spin faster, thus supplying the engine with more air.

Thus, the engine kicks in and it is no longer necessary to supply air from the reservoir before the turbocharger because the resulting exhaust gases will take over this work.

Limits of PowerPulse technology

However, the PowerPulse technology only works up to a speed of 30 km/h, so it is practically only active at start-up when the delay in the reaction to the gas is most pronounced. The result of using this technology is a better response to the addition of gas and the elimination of turbo lag.

Watch a short video demonstration of how the PowerPulse technology works: