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Old 09-25-2009, 08:21 PM   #9 (permalink)
shovel
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Quote:
Originally Posted by JohnnyGrey View Post
This is definitely NOT a myth. An increase in exhaust diameter results in a reduction of exhaust velocity and therefore scavenging. Yes, a larger exhaust will open up your top end because there is a limit to exhaust gas velocity, but when you lose that velocity on the low end, you lose power. The same principle applies to the intake runners.
Yeah i see those words written on automotive message boards all the time.

What i have never seen is a dyno sheet or any other actual evidence proving them. Ever. Just words and theories.

Just dozens of dyno sheets showing net increases in torque and horsepower across the board from idle all the way up, from increases in exhaust diameter.
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