In all TDI engines from Audi, the turbochargers have variable turbine geometry on the exhaust side. Variable turbine geometry (VTG) technology builds up torque smoothly and without delay, even at low engine speeds.
http://www.eurocarnews.com/29/0/1314/0/video-audi-turbochargers-with-variable...
A fixed ring of blades fitted on the optimum position can do the same work without malfunctions and the discharge of bypass outside of the turbo in order to decrease the turbo device temperature, less gas passing across the turbocharger less temperature for the body and better air.Pls see my video of the diesel motor 2 strokes by valves only.
ricardojp07 3 days ago
@b3llmann It's not, the vanes are only shielding about 50% of the spindle when closed at low rpm. The idea is when the gap is smaller the gas has to compress as it passes through the spindle to escape, thus it has more push to make the turbin spin faster at lower rpm.
Blunder1248 1 month ago
@b3llmann the thing is thats its not closing up to 100%!
stubbi 1 month ago
how can the emissions leave the system when its closing up?
b3llmann 1 month ago
Without delay.... LOL
It's like if they claim it works just like a rally anti-lag system... There's always delay.
guily6669 3 months ago
simerler setup for SC or no actuator = no variable? thus confuses me, teach more
WarlDogg 3 months ago
@Dalit5 The vanes are open and closed via a gas driven actuator. The gas driving this actuator is the output from the turbine. If the turbine pressure falls, the gas-pressure fed into the actuator also falls which closes the vanes. The reverse also being true. What I find intellectually difficult is why its taken so long to develop as the principle upon which its based is so simple.
Sidowse 8 months ago
@Dalit5 It's all about keeping the speed and pressure of the gas constant. At low rpms the red-vanes are partially closed, the reduction in cross-sectional-area through which the gas flows means that the speed and pressure of the gas over the turbine blades remains high. As the volume of gas increases from increasing rpms, the cross-sectional area must also increase to keep the speed and pressure of the gas constant, therefore the vanes open up further.
Sidowse 8 months ago