[Tom Vaught]

Think about two freight trains (with the exhaust pulses being the "Box Cars").

One freight train has a one minute head start on the second freight train.
This is simulating the exhaust pulses from say the passenger side exhaust manifold and transfer pipe to the
split scroll housing being shorter vs the drivers side exhaust manifold and transfer pipe to the other inlet of
the split scroll turbo.

The energy pulses are like marbles traveling down a pipe. At high rpm are they are almost a solid stream
of pulses on the turbine wheel. Only at start-up before idle are they reaching the turbo wheel at different times.

The turbine wheel is driven by two "nozzle points" inside the turbine housing.
So if one nozzle point has the exhaust points hit the turbine wheel slightly before
the other turbine wheel at original crank and firing, no big deal.

As soon as the other bank of cylinders has starting its firing then the exhaust pulses
are from both sides of the engine. Now the pulses are both powering the turbing wheel equally.
It was only on the initial firing point of engine start when the pulses from the drivers side was not
helping the passenger side of the turbine housing.

Each pulse has energy so keeping the pipes fairly small keeps the response (spool) time of the turbo
shorter. But at some point they are both trying the equally drive the turbine wheel.

The gas travels thru the pipe at about 500 meters per second. This is 1500 feet per second.
So the difference in the two pipes in length, (say 12") or 1 foot difference or 1/1500 difference
in the initial time the first marbles got to the turbine wheel for the split scroll exhaust system
energy transfer to the turbine wheel.

It doesn't make any difference if the pipes are slightly different in length.
Some guys have mounted their turbos under the car and left the engine compartment
looking stock in street racing vehicles. Since the set-ups are mostly converter cars and
the guys are launching at higher rpm the "marbles" have been driving the turbine wheel
for a goodly period of time before the car/vehicle ever leaves. Again, not an issue.

Tom V.