To improve fuel economy or gain horsepower means making the engine more efficient. Fuel economy or maximum power is only obtainable when the correct
air/fuel mixture or ratio (a richer mixture for power and a leaner mixture for economy) is ignited by the ignition system at the correct time. In this way, all the energy of the richer air/fuel mixture is converted to power; similarly, the leaner mixture gains fuel economy because its charge is burned completely.
A high-performance engine will only perform at its best when the initial timing and the ignition advance curve are tailored to suit the engine, the fuel, the owner’s driving style, usage, etc. High-performance carburetors, intake manifolds, cylinder heads, camshafts, and other tuning components are all dependent upon correct ignition timing; if the spark is not delivered at the proper time to the combustion chamber, the quest for power or economy is for nothing.
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