Turbocharger - BMW N55 Manual

Turbocharger

The N55 is equipped with a single twin scroll turbocharger instead of two separate small
turbochargers as on the N54 engine. The following graphics shows the operating princi-
ple of the twin scroll turbocharger.
Twin scroll turbocharger rear view
Index
A
Exhaust duct 1 (cylinders 1 - 3)
B
Exhaust duct 2 (cylinders 4 - 6)
C
Connection to catalytic converter
D
Inlet from intake silencer
E
F
Outlet to intercooler
1
62
N55 Engine
Explanation
Ring channel
Wastegate valve
Index Explanation
2
Lever arm, wastegate valve
3
Vacuum unit for wastegate valve
4
6
8
10
11
Diverter valve
Turbine wheel
Cooling duct
Oil return
Coolant return