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Old 05-17-2011, 11:17 PM   #56 (permalink)
The road not so traveled
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Join Date: Jan 2010
Location: New Mexico
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The Truck - '99 Nissan Frontier xe
90 day: 25.74 mpg (US)

The Ugly Duck - '84 Jeep CJ7 Rock crawler
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After looking closer at the equations, I did notice a correction for intake manifold pressure.

a = inlet sonic velocity, which is dependant on pressure. Which means at lower throttles will yield better VE at lower RPM.

Larger/more open valves lower Z raising the RPM of best VE.

So would what would altering the intake runners do? such as smooting out the sides to get higher flow velocity (not increasing the runner volume by much I hope)?

All of this is fine but how does it relate to the real world? Does best VE correspond to the torque peak?

How does this relate to engine efficiency?
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