Benefits of Variable Geometry Turbochargers

A turbo, driven by exhaust gases can compress incoming air into the engine. The side of the turbo which receives the energy from flow and the heat from the exhaust system is termed as the ‘hot’ side of the turbo. The other side or the ‘cold’ side of the turbocharger is able to pressurize fresh air and force it into the engine. This pressure is called the ‘boost’. A shaft that is connected to the ‘hot’ side drives the ‘cold’ side. One big drawback of the turbocharger, besides its cost, is the fixed geometry.

Variable Geometry Turbochargers:

Turbochargers, whose geometry can be altered as required when in use, are called variable geometry turbochargers. In turn this can alter the effective A/R(Aspect Ratio). There are many designs to this, but the most common one consists of several adjustable vanes around the turbine. These can change the A/R (Aspect Ratio) by changing the angles of the vanes, which in turn can change the angle of air flow onto the turbine blades, thus changing the effective area of the turbine.

Benefits of Variable Geometry Turbochargers Lag time decreased:

Working as nozzles, the area between the adjustable vanes are varied in size as a function of the conditions of engine operating. Without any restriction the turbo is able to produce boost from a lower speed. Since this can be done at a lower speed of the engine, there is a decrease in lag time. The boost pressure is easily altered without any change in the speed of the engine as the vanes are remotely controlled. Adjustment of the vanes can increase exhaust manifold pressure during gear changes. The stored energy, which is in the form of pressure, can be used to drive the turbo to a higher boost level even faster. Lag is reduced once again due to the increase in the boost level.

Efficiency:

These turbo chargers are extremely good at increasing the efficiency of the engine. The intake being pressurized manifold, and so more fuel gets in the cylinder. This happens every time with the opening of the intake valve, creating a volumetric efficiency which is more than one. This volumetric efficiency of even only one is almost impossible in any engine without any forced induction occurring due to friction losses. The efficiency of the engine is improved overall as the engine is allowed to burn more air and fuel with every cycle. The generated pressure helps in overcoming any casting defects, like surface roughness or even tight corners. This is done by providing a larger pump head or diving force. Fixed Geometry turbochargers (FGT) work similar to other centrifugal pumps having a limited operating range. With VGT s or Variable geometry turbo, many pressure ratios of a different kind can be produced at one engine speed. This is due to the variable vanes changing the A/R and the effective area. As the vanes can be manipulated, they are able to create a boost pressure at any speed. Producing the boost through an engine speed which is large, the efficiency overall is increased.

Getting Variable Geometry Turbochargers:

Going through the different websites and gathering a thorough knowledge of these turbochargers you can choose one to fit your requirement. Investing on this is long-term, since you are given the comfort of an efficient engine without problems. It is better to decide before you opt for turbo. In this regard you need to think of what type of turbocharger you would like for your vehicle. Saving on fuel and having the comfort of driving at ease, these Variable Geometry turbochargers seem to work perfectly. Here at Eastern Turbochargers, turbo specialist offering VNT turbo and variable geometry turbo.