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Old 11-06-2014, 03:16 PM   #12 (permalink)
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Originally Posted by Old Mechanic View Post
At 10 inches of vacuum steady, try pulsing at 2-3 inches and gliding as much as you can. Super shallow grades can allow you to store energy at higher bsfc. You get more power from the same amount of fuel at 3 inches, maybe even up to 5.

On sustained uphills but very shallow grades, you might even pulse the flat spots and use inertia as much as you can on the uphills.

If you are using engine on pulses, then go a little higher on your peak speed which increases your mileage in the glide.


Its not actually 10.5 inches of vacuum. Its 10.5 psi of absolute pressure in the manifold. 14.5 would be WOT at sea level. So, the chart is telling me peak efficiency is ~4 psi of vacuum. This is the equivalent of the engine being 73% loaded as shown on the chart.
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