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Old 11-19-2010, 08:07 PM   #229 (permalink)
dennyt
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Quote:
Originally Posted by Zerohour View Post
I'm going to try to do some intake changes to see if I can reduce air flow into the intake at lower throttle positions. I can take my vacuum gauge to zero at less than 25% throttle. Its not so much fuel hungry as the engine is air greedy.
Um... no.

Your throttle plate is sized by the maximum rated power of the engine - floored at 6500 rpm, let's say. Under light load or at low RPMs, the volume of air going through the engine is much lower, say 10% of the max power case. So, naturally, a ~10% throttle opening will give you full pressure (zero vacuum) at low RPM.

You could work on a non-linear throttle mechanism if you want better control of the first half of throttle opening. But getting zero vacuum at low throttle openings at low RPM is just the nature of a throttle plate.
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