Exhaust manifold

Fig 1: Exhaust Manifold Flow Diagram

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The exhaust manifold is partially pulse separated. This means that the exhaust gas from cylinders 1 and 4 are led to the turbine wheel separately from the exhaust gas from cylinder 2 and 3. This offers the advantage of shorter reaction times, i.e. faster response to accelerator pedal movement, thanks to the exhaust pulses being more distinct when they are not disturbed by pulses from the other cylinders and that flushing the cylinders is not disturbed by exhaust pulses from the other cylinders.