What is in a turbocharger system?
– Turbo – duh! – Wastegate – this is a spring loaded valve that opens and closes. It is responsible for maintaining turbine speeds and thus boost pressure. When it is open a good amount of the exhaust gas is diverted away from the turbine, hence the turbo does not spool. When it is closed the exhaust gas is directed towards the turbine and the turbo spools. These can be incorporated into the turbo (internal wastegate) or included in a seperate valve that is incorporated into the exhaust manifold. – Exhaust Manifold – the design of the manifold is a key to lag reduction… it differs from a normal header in that it generally has short runners to maximize exhaust velocities and thermal energy. One key design factor that can describe the differences in inline 6 and inline 4 manifolds is the inclusion of exhaust pulses. To optimize a boost curve you want to use an equal length manifold system so that you aren’t surging the exhaust turbine with 4 pulses per revolution. This can cause boost
