How does the VNT works?


The VGT turbocharger is effectual, although complex mode turbocharging, which uses the automatic variation system of intake power during the operational engine work. This allows optimal setup turbine power necessary to compressor to create needful pressure for operational engine work. This is achieved by variable zone of splash, apropos, the set of controllable vanes control the flow through the turbocharger.


The VNT turbochargers regulate the turbine intake section in purpose optimization the power whereby assignment air flow intensity.



At low engine speed and low fuel flow turbocharger reduced intake section, which results in increasing the boost pressure and the turbine power output. At high engine speeds and high fuel flow VNT turbocharger increases intake section. This prevents achievement of rotor assy critical speeds in turbocharger, and also sets optimally boost pressure for each operating point. Modulation of the intake section can be directly control by compressor pressure and with use of swing valve actuator or vacuum-regulated type. In purpose of modification the intake section, the VNT types use variable guide vanes, which rotate in correlation with turbine wheel assembly.


Advantages of VNT technology are:


  • More power output
  • Higher torque
  • Reduced fuel consumption
  • Reduced emissions
  • Improvement of brake power
Holset’s VGT is unique by axial glide the vanes instead to roll.

This mode allows high level duration and reliability, which is very important for commercial diesel application.

The new generation of VNT turbochargers for variable geometry regulation uses electric motors controlled by an ECU engine computer.