You may remember our Tech Talk segment on turbo-lag; what it is, what it isn’t, and the ways around it. At the time of writing, there were only a few ways around it, with the most likely going forward in production cars being ‘electric turbocharging’. Audi has proven us right with their e-turbo found in the SQ7, but one manufacturer has thought of an unorthodox solution to solving turbo-lag in their diesel models. Volvo has released what it calls PowerPulse; but what is Volvo PowerPulse, how does it work, and are there any drawbacks? Let’s take a look.
What is Volvo PowerPulse?
Simply put, Volvo’s PowerPulse is the latest anti-lag technology to surface in the market. It’s an incredibly simple idea, too – a tank of compressed air that, at a moment’s notice when the throttle is applied, releases into the turbocharger to speed up spooling and reduce lag.
This seemingly simplistic system negates the need for fancy electric compressors and 48-volt electric systems that require extra batteries and additional wiring harnesses – not to mention the potential for extra problems if something goes wrong. As it doesn’t constantly pressurise the turbocharger, there’s also a low likelihood of premature damage that may occur using traditional anti-lag systems.
How does Volvo PowerPulse work?
There are 2 key components to the Volvo PowerPulse system – a small compressor that runs off the car’s existing electrical system, and a 2-litre tank that holds compressed air at a pressure of 12-bar, with a magnetic valve to control the release of this pressurised air.
The compressor fills the 2-litre tank with air from the air filter (blue veins in image above), and the tank remains pressurised until a throttle application is made. When the driver applies the throttle sharply, instead of waiting for the exhaust gases (red in picture below) to spool the turbo – this can take a while due to the slow burning process of diesel – the magnetic valve releases a sharp burst of compressed air (green in image below) directly into the exhaust manifold of the Drive-E diesel engine.
This in turn spools the turbo up rapidly – Volvo claims 150 000rpm from idle in 0.3 seconds – allowing the engine to deliver its full payload of torque with minimal delay.
The PowerPulse system weighs only 10kg, a minimal weight penalty for fairly immediate response.
What are the benefits of Volvo PowerPulse?
Due to its simplicity, Volvo’s PowerPulse offers several benefits:
- Minimal weight penalty
- No need for additional batteries
- No need for additional 48-volt wiring systems
- Almost instantaneous response to throttle inputs
But, there are potential drawbacks to using the Volvo PowerPulse system…
What are the drawbacks of Volvo PowerPulse?
There’s only really one, though one that Volvo claims is an unlikely occurrence – is that due to the small displacement of the air tank, PowerPulse can only deliver two bursts of pressurised air in quick succession. ‘Quick succession’ is a relative term though, in this case referring to a press, release, and rapid re-application of the throttle – almost a hesitation rather than completely lifting off. The likelihood of more than two rapid applications of the throttle in the real world is incredibly minimal though.
To call the Volvo PowerPulse system a simple one seems appropriate – though if any of their engineers overhears you say that they’ll likely not take to it well. Despite the simplicity of the idea, it took some work to get it to function as well as it does. However, the effort has paid off, and the Volvo PowerPulse system combines with Drive-E engines in the S90, V90 Cross Country, and XC90 to develop super response to throttle inputs, especially for 4-cylinder diesel engines.
Simplicity, as Leonardo da Vinci said, is the ultimate sophistication. Centuries later, Volvo seems to have taken this mantra to heart.