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HYPREX pressure wave charger

In the early 90’s swissauto WENKO AG has been highly integrated into the development of the Swatch-Mobile, today named Smart. We have already realized at that point of time that engine downsizing and charging-related torque recovery will be the future solution in engine production. We recognized the limits of turbo charging quite fast as we were busy with high-charging techniques of gasoline engines at a very early stage. Based on that knowledge and our large experience, we decided to search for an improved charging technology. We evaluated that the “Comprex pressure wave charger” (Similar to the turbocharger, invented and developed in Switzerland) might be the appropriate system.
In 1994 we have taken the step into intense the the pressure wave charger development. Our company was first in implementing the principles of pressure wave charging into an internal combustion engine, suitable for dayli use. In spite of close collaboration with Comprex AG Company it was swissauto Company who draw up all patent applications regarding the relation of pressure wave charging for spark-ignition engine use.
We came to the conclusion that the performance of the pressure wave charger is much more efficient when combined with a spark-ignition engine instead of a diesel engine. Unfortunately we had to realize, that more than we ever imagined, this mechanical controlled resonant machine is much more difficult to adjust for the large and tricky spark-ignition engine maps. The enormous thermodynamically advantages, the proverbial reliability and the direct responding speed kept us motivated all years long to press ahead with that expensive and large-scaled development of that machine. The huge progress in engine control engineering has been the biggest help.
Similar to the gasoline direct injection system which was first presented in the 50’s, also this pressure wave charger would net succed without today state of the art engine electronics possibilities.
The benefits of the Hyprex system
  • very high pressure ratio’s at low rpm possible 
  • fast response, better than any 2 stage charging system
  • highest Co2 reduction petential over all charging systems
  • best emissions behaviour; the PWS is an integrated part of the emission treatment system  
  • very good compression efficiency at low mass flow and high PI
  • very reilable due to low rpm, no cooling and lubrification
  • Cost and weight benefits over all 2 stage charging systems