• When calculating the average number, flow at .100 lift is not used.
• When calculating the average exhaust / intake ratio there needs to be more than 2 flow numbers, and the number of intake and exhuast count must be equal. If present this will be line 2 in the average column.
• When calculating the CFM flow per cc of intake port only the highest intake flow number is used. If present this will be line 3 in the average column.
• Bigger is not always better (Highest flow numbers and/or largest port volume). -- Velocity is just as important.
• We want the best flow number's with the smallest volume and the highest velocity.
• Remember to compare all flow numbers. -- Low lift flow does help performance.
• Looking at flow numbers near or above max. valve lift are meaning less.
• For street engines airflow at 0.400 inch lift is a good place to evaluate flow.
• Check the exhaust / intake flow ratio. If there this will be the third number in the cell.
• We show a max power number calculated using 3 different formulas .400 and .500 use one from AFR as show in a number of magazines, .600 and .700 uses a comp type formula and .800 and .900 uses almost a Pro Stock type. Because this number is program generated and uses 8 cylinders it will generate bad data if the engine is other than an 8 cylinder. Some engines have had an override added to make them come out correctly ex. Harley-Davidson.
• For a supercharged, or nitrous you will need a higher intake exhaust ratio.
• Use these numbers only as a rough guide.
• Remember when doing a comparison to other tables check at what pressure differential were they flowed?
• There is a calculator on the main page to convert flow numbers from one pressure differential to another.
• One reason exhaust numbers maybe off is if one person attached an exhaust tube.
• Another reason numbers may vary is valve size, and bore fixture size.

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