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Reply-To: "kevin lane" <n3773@comcast.net>
From: "kevin lane" <n3773@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-564625@logan.com>
Subject: breaking physics news!
Date: Sun, 12 Dec 2004 14:04:47 -0800
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i came across this while looking for stainless steel tubing -


      FACT! Before purchasing an oversize 2-1/2" exhaust system give it a 
little thought! The problem with 2-1/2" exhaust tubing (a common size 
mistake) is that the velocity in the system decreases with larger diameter 
tubing. This reduction of velocity is caused by the exhaust expanding in the 
larger tubing. This actually produces more back-pressure by slowing the 
flow. The result of this is a significant decrease in low end (2000-4500 
rpm) performance of your Toyota's engine.


wow, i guess toyotas use different laws of physics :-)  i thought the 
backpressure squared was proportional to the airflow velocity.