The main aim of FSI technology is getting more out of every drop of petrol. FSI engine is a combination of low fuel consumption and the characteristic that ensures high performance and agile responsiveness.
In this technology, fuel is injected directly into the combustion chamber. The injector regulates the amount of fuel with injection pressures of 30 to110 bar. During the injection process, the cylinder charge gets a cooling effect from the evaporating fuel. This increases cylinder charging. As a result, engine power output also gets increased. Engine’s tendency to knock also gets reduced. Compression ratio of FSI engines is considerably higher than conventional injections.
FSI engine family engines are fitted with a two-stage variable intake manifold. The power mode at high engine speed helps in high power output of engines. At low revs, a longer duct length is chosen. This way, the maximum torque is increased by more than 15%.
The in-cylinder flow can be adjusted by a flap system of the intake duct. In part-load operation, a stronger flow helps in lower fuel consumption and lower amount of exhaust emissions. When fully loaded, air is drawn inside with minimum amount of loss. This way torque and power output gets increased.
The new V6 FSI engines have Audi valve-lift system that offers intelligent control of intake valves. Consequently, power and torque gets increased by reducing fuel consumption. Audi uses this in V6 FSI engines with 2.8, 3.2 litres displacement.