Douglas Fir wrote:

Paul

I noticed a lot of posts recently about tuning intakes.  I assume the
same
is true for exhausts.  If the angled  outlet pipe of tangential
muffler
Jerry is making has the exhaust pipe sticking out in the slip stream I
believe it should exhibit a slight vacuum thereby helping to draw out
the
exhaust better.  Turbo props exhausts take advantage (need to) have
this
design.

Q. If this vacuum phenomenon is maximized does it alleviate the need
for
tuned exhausts?

Seems hard to calculate the tuning on how gases travel in a large
chamber.

Doug in Japan

They are a big unknown. Hope to measure the pressure when I get my dyno
going. Everett Hatch maintained the optimum length for two individual
pipes
was 32 inches. Most of the headers that Racing Beat sells are about
this
length. The speed of sound varies from the intake manifold due to the
heat
of the exhaust gases.


Paul Lamar

Doug,  I expect low pressure at the exhaust pipe outlet to help
scavenge exhaust gasses.  How pronounced the effect will be is unknown.
   Once the lower cowl is fitted, the pipe can be trimmed to enhance
this effect.    Jerry

 
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