> If the pipe is to small it restricts the
> flow of the pulse (slowing it down).
Velocity = flow/(density * area)
For a given flow rate, a smaller diameter yields
higher velocity. But the flow is not going to be
constant - with increased backpressure, there will be
less flow. It just isn't that simple. Sonic
velocities are important to the scavenge effect, and
the timing of the shock associated with expansion of
the exhaust gas.
If the pipe is
> to large the pressure of the pusle dissipates
> and there is no scavanging. I would suspect the
> stock exhaust size is pretty close to correct
> as the original engineers knew about this issue.
> They did make compromises in the exhuast manifold
> (for cost, longevity, etc.) so a set of headers will
> help performance.
>
=====
Ron Soave
"You Are What You Remember"
1960 Bugeye
1972 BGT
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