the future is vg

Variable geometry has been a popular way to turbocharge diesel powered vehicles for the past 10-20 years. VG is an attractive technology as it can provide a high boost pressure from low to high speed engine ranges. Due to the VG nozzle vanes, the turbocharger can switch between a small and large throat area depending on the engine speed. This reduces the turbo lag at low engine speed compared to a waste gate turbocharger, without adding too much boost at higher engine speeds. In recent gasoline engine developments, the Miller cycle and EGR are used to increase efficiency. This means that the turbocharger requirements have changed and variable geometry turbocharging for gasoline engines has become more beneficial.

To get a better understanding of how this technology works, please take a look at the short animation below:

Modern gasoline engines operate on high exhaust temperatures to reach legislation emission levels. For this, Mitsubishi Heavy Industries Engine and Turbocharger (MHIET) has selected material compositions that are suitable for these high exhaust temperatures. Furthermore, durability has been prioritized with MHIET designing moveable components in a way so that wear is reduced to a minimal level.

At MHIET, we have developed a new generation of compressors in order to achieve new gasoline engine requirements. The aerodynamics of the compressors was designed to achieve a higher pressure ratio ( to aid a Miller cycle combustion engine) and more surge margin. The aerodynamics of the turbine was also improved to achieve the required wide flow range and high efficiency (to aid a Lambda 1 combustion engine).
MHIET has received awards for many different VG gasoline turbocharger customer projects.

With the developments mentioned, MHIET has developed a high performing and durable variable turbine technology for future gasoline engines. VG for gasoline is forecast to be one of the biggest trends in turbocharging in the coming years, helping OEMs to achieve increasingly strict emissions legislation in Europe and globally.