In a conventional twin turbo engine, the setup usually is such that one turbo is larger, and the other is smaller. This is because the smaller unit has a lighter compressor, which is able to spool up quicker as compared to that of larger turbo’s compressor. Faster the spool, lower the turbo lag.
Instead of two turbochargers, this new Volvo Drive E Concept comes with 3 turbos. Two are parallel conventional one’s, while there is a additional smaller third unit. This smaller unit’s compressor is spooled electrically, using an electric motor, thus the compressor not needing exhaust gasses in order to spool up. The compressed air from this electrically driven unit, is then used to spool up the two parallel turbochargers. This triple boost arrangement, Volvo claims, delivers “dynamic drivability without any turbo lag”.
This technology is new for a four cylinder engine, but the concept is already seen in 2014 F1 cars, and 2014 WEC. Also, Audi had announced a similar arrangement for their concept RS5 TDI earlier this year, which was a twin turbo, unlike Volvo’s triple turbo.
Volvo Cars reveals 450 horsepower High Performance Drive-E Powertrain Concept
Triple Boost Technology takes Volvo’s four-cylinder Drive-E Powertrain petrol engine to 450 BHP
Further proof of Volvo’s commitment to delivering driving pleasure through down-sizing
Volvo delivers a unique combination of performance and efficiency with the High Performance Drive-E Powertrain Concept – a triple boost 2-liter 4-cylinder petrol engine with no less than 450 hp.
Following the successful introduction of Volvo’s Drive-E Powertrain range in 2013, Volvo’s powertrain team once again demonstrates its technological leadership in emission-reducing turbo technology.
“When we launched the Drive-E powertrain family, our aim was to deliver the most advanced 4-cylinder engines in the industry based on emissions and fuel consumption relative to performance and drivability. We knew that 320 hp in our petrol configuration was just a starting point. The 450 hp High Performance Drive-E Powertrain Concept, demonstrates this ambition and the versatility of the Drive-E Powertrains,” says Dr. Peter Mertens, Senior Vice President for Research and Development at Volvo Car Group.
The 450 hp High Performance Drive-E Powertrain Concept is based on a set of technologies not usually found in a four cylinder engine. The engine utilizes two parallel turbochargers, which are fed by an electrically powered turbo-compressor. The compressed air from this unit, rather than being fed to the cylinders, is instead used to spool up the two parallel turbochargers. Fuel is fed by a dual fuel pump working at 250 bar pressure. With this kind of power density, this triple boost installation and unique fuel system, enables a very dynamic drivability without any turbo lag, compared to a mono-turbo.
“There are several high power small size applications where one large turbo is used to create a high level of power available from other manufacturers, but the driving experience suffers due to slow engine response. We felt that with our heritage of being among the first car companies to embrace and offer a broad range of turbo technology since 1981, that we could improve this,” says Michael Fleiss, Vice President of Powertrain Engineering at Volvo Car Group.
The High Performance Drive-E Powertrain Concept attracted the attention and involvement of Volvo Cars suppliers AVL, Denso and Volvo Polestar Racing at an early stage, which allowed theories and technologies from racing applications to be infused in the development process.
“This was a very exciting project as we pioneered a combination of technologies in the same application, and the result is a quite unique engine with its high power yet quick response. Above all, its compact size improves weight distribution between the front and rear axle and lowers the center of gravity – two factors that have a significant effect on the handling, whether it is a race car or a street car,” said Mattias Evensson, Race Engine Director at Volvo Polestar Racing.
“It may sound odd, but this 450 hp powertrain concept is an important part of the Drive-E development program. Down-sizing must offer customers attractive and usable power for broad scale emissions reduction to work. Compact powertrains free up space and weight in the structure of the car, which can be used for electrification and even further emissions reduction. And that is our ultimate ambition,” concludes Dr. Mertens.