Automotive isn't my speciality, hence low CL, but a bit of googling throws up this sort of thing:

Turbocharger turbines can receive the exhaust gases that power them continuously or in pulses. In constant pressure turbochargers, a larger manifold is employed to smoothen out exhaust flow before approaching the turbine blade. In contrast, in pulse-turbochargers specially-designed exhaust manifolds aid the power extraction from the kinetic energy in the exhaust gases. Constant pressure turbocharger manifold designs are generally found in relatively large engines with steady engine speeds and loads. For passenger vehicle engines pulse turbocharger manifold designs are more reasonable.
https://www.ukessays.com/essays/engineering/produced-mechani...