Expansion suction system
The expansion suction system is a suction system for turbo engines that uses the expansion phase of the air vibrations in the intake manifold. It was developed by Porsche and has been used in the 911 GT2 (Type 997) model since 2007 . The technical structure differs from the usual resonance suction system in that it has a longer distribution pipe with a smaller diameter and shorter suction pipes.
Working principle
Air flows through all suction systems. In addition to the air flow , air vibrations also occur , which consist of a compression phase (air compression ) and an expansion phase (air expansion).
- In the classic resonance intake system , the air in front of the combustion chamber is used in its compression phase in order to fill the cylinders with as much air as possible for high performance. However, when the air is compressed, it heats up, which means that the fuel-air mixture cannot be ignited in a way that optimizes performance and consumption.
- In the expansion suction system , the air in front of the combustion chamber is used in its expansion phase , although less air gets into the cylinders. Since air cools down when it expands, the now cooler fuel-air mixture can be ignited for optimum performance. The disadvantage of the expansion suction system that less air gets into the cylinders is offset by a slightly higher boost pressure in the turbocharger . The warming of the air due to the higher charge pressure is also compensated for by optimized charge air coolers .
literature
- Gert Hack , Iris Langkabel: Turbo and compressor motors . 1st edition, Motorbuch Verlag, Stuttgart, 1999, ISBN 3-613-01950-7