User Manual

Chapter 4
BOSCH HDI EDC 15C2 INJECTION SYSTEM AND PARTICLE FILTER
26
VI - VARIABLE "SWIRL"
SDI009C
b
a
a - Short inlet duct (helical shape)
b - Long inlet duct (tangential)
Using the short inlet duct allows maximum swirl to be obtained (swirl movement).
Air is let into the inlet ducts by opening the "Swirl" control butterfly valve at high engine
speeds.
Using 2 inlet ducts allows maximum filling (reduced swirl).
Advantages of the variable "Swirl":
• optimisation of combustion (air/fuel mixture),
• better performance/pollutant emissions compromise.
The variable "Swirl" gives a reduction in carbon particles.
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