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Old 10-02-2010, 01:18 PM   #28 (permalink)
Meph
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Join Date: Apr 2008
Location: ontario
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240Z - '73 Datsun 240Z 240Z
90 day: 34.41 mpg (US)
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Heres more info relating to intake timing, an advance in intake timing would help to raise compression ratio and efficiency in lower rpm.

"Dynamic CR
At low rpm, there is little-to-no ramming of the cylinder from intake charge velocity. As the piston starts to move up the bore on the compression stroke prior to the intake closing, some of the induced air is pushed back into the intake manifold. This means the volumetric efficiency (breathing efficiency) and thus the effective displacement of the cylinder is well below 100 percent."

So maybe adding +2 intake degrees to my current +4 exhaust would help to shift the power band lower in rpm (+2,+2), raise Dynamic compression raito (advancing intake valves to close sooner) and reducing overlap (+4 exhaust - 2 intake = +2 exhaust net)

Reset my timing, and see how it drives
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