Economy without sacrificing driving pleasure is the new engine recipe for automakers. In addition to the turbocharger, the compressor, which for a long time was primarily found in sports cars, has become an indispensable aid. This will enable engines for small cars and compacts with low thirst but high power and good responsiveness.
Engine displacement reduction
The old solution "there is no substitute for displacement, except more displacement" no longer applies. Today, a modern four-cylinder turbo engine with a displacement of just 1.4 liters achieves performance figures for which conventional naturally aspirated engines still require at least two liters. This reduction in engine displacement is often referred to as "downsizing". Turbochargers and compressors provide the engine with additional "breathing air" and thus compensate for the low engine displacement. The superchargers draw in air from the environment, compress it and blow it into the combustion chambers. Technically, this is expressed in a better filling ratio, so that more oxygen is available for the combustion of the fuel. Performance increases.
But turbocharged engines are also significantly ahead of their big brothers when it comes to fuel consumption. The main reason for this is lower friction; according to compressor manufacturer eaton, savings of up to 20 percent are easily possible. The compressor mainly solves the old problem of turbo lag. For a long time, gasoline engines with turbocharging suffered badly from this annoying pause in acceleration. Because in order to get going, the turbocharger needs sufficient exhaust gas to start the turbine for air compression.
However, the exhaust gas pressure of gasoline engines is rather low compared to diesel engines. Particularly when accelerating from a low load, there was a lack of sufficient pressure. Once a certain rev level is reached, the turbo power often kicks in abruptly and very violently. The compressor, on the other hand, works at low engine speeds. [foto size="small" position="right"]it does not rely on exhaust gas pressure as it is moved by the engine via chain or belt drive. As a result, it presses the required air into the combustion chambers immediately and without delay.
Use of the system
The system is currently used in a number of VW engines, such as the 1.4-liter TSI gasoline engine with 118 kW/160 hp for compact models like the VW golf or the VW scirocco. Recently, this technology received the prestigious "engine of the year 2009" award.
But the compressor is not only used in twin-turbocharged engines for compact cars; the supercharger also makes powerful engines for sports cars more fuel-efficient. This is demonstrated by the new audi S4, for example. Until the end of 2008, the high-performance mid-range was still equipped with a naturally aspirated V8 engine, but the new generation has a six-cylinder gasoline engine charged by a compressor. The 245 kW/333 hp engine is only eleven hp weaker than its much larger and more fuel-intensive predecessor. Fuel consumption falls from 13.3 liters to 9.7 liters of fuel. In terms of performance, the current mid-size sedan even outperforms the outgoing generation, not least because of its lower weight: it reaches 100 km/h in 5.1 seconds, compared with at least 5.6 seconds previously.
In future also in very small engines
In the future, the compressor will also help very small engines achieve greater fuel efficiency. Eaton’s european boss joao faria expects his company’s small engine business to grow by around 80 percent over the next few years. It would then also be conceivable to use one-liter engines in the compact class, which would have the performance of much larger engines.
- 333 HP
- Car news
- gasoline engine
- Driving pleasure
- Small car
- Compact cars
- In addition to
- Belt drive
- naturally aspirated engine
- Fuel economy
- Sports car
- V8 suction engine
- VW golf
Written by (hh/mid) published on 24.06.2009 updated 24.06.2009