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Old 03-02-2012, 09:19 PM   #99 (permalink)
drmiller100
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Quote:
Originally Posted by Olympiadis View Post
For any given combustion event a falling average RPM of 2000 RPM will have a much slower piston speed than a rising average RPM of 2000 RPM.
kind of ok until here. you are missing the CAUSE.

the cause is if the rpm is slowing down, typically MAP is relatively low. If the RPM is rising, then MAP is high, and the driver is trying to accelerate.

The first case allows LOTS of spark advance, the second case much less spark advance.

In the cylinder, the spark ignites the air/fuel mixture. The rate of burn is measured in inches per second.

The time the piston has to hang out and wait for the burn is a function of RPM.

How fast the burn is going off is related primarily to cylinder pressure which is based in large part on heat, and when all done, MAP.

So. The lower the MAP (the higher the manifold vacuum) the slower the burn, so the more spark advance you need for "efficiency".

The higher the RPM, the more spark advance for efficiency.

If we lean the mixture out past 14.7 with high manifold vacuum, the flame burns much slower, so we need more spark advance.

As for HHO and nitrous, all of your comments are pointed towards making maximum horsepower, which implies wide open throttle. If we desire more power at part throttle, the EASY answer is to open the throttle more.

Nitrous has half of its effect due to the extra oxygen, the other half becuase NOS is COLD - it supercools the charge allowing more air molecules into the cylinder.

NOS makes no sense for better mileage. HHO makes no sense for better mileage, unless you are a unicorn salesman.
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