Russell Kent wrote:

Paul,
It appears to me that you could rotate the muffler can about the axis of the
forward exhaust port centerline about 20 to 30 degrees clockwise.  This would make
the exhaust bends shallower at the expense of making the cooling air take a small
(20 to 30 degree) turn to enter the interior cooling pipe.  It would also setup
the exhaust pulses so that the forward rotor's pulses swirl left-hand, and the
rear rotor's pulses swirl right-hand; dunno if that's good or bad.

Russell Kent

I think it would be bad. I think it would tend to cancel the swirl.
the swirl is good as it causes the high speed exhaust gases to rub
on both the outer can and the inner can. According to the book the 
Scientific Design of Exhaust and Intake Systems This rubbing action is the 
main phenomena that causes a reduction in the noise level. The energy
in the noise is converted to additional heat in the skin of the muffler.
In this case both the inner tube and outer tube skins. If this vortex can be
maintained in the tail pipe in theory a further reduction of noise
will take place.

Paul Lamar
 
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