Turbo header design

[Dave Williams]

-> My question is: why can't this be applied to the header of a turbo'=
-> d engine: pre-turbo.  I know that the turbine is already turning and
-> = therefor creating a vacuum; but, at velocities reaching .75 mach,
-> wou= ldn't any tuning, like using the 180 out exhaust arrangement
-> help??  =

 That's exactly how the factory exhaust on my Yamaha XJ650 Turbo is
configured.  It could be considered a long 180 collector or a short
second branch tri-Y.  The service manual says it smoothes the exhaust
pulses to make the turbo slightly more responsive than a normal
collector.