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Calculation of VE engine Air

EFI Tuning Fundamentals

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The calculation and and how to measure is all confusing as a beginner.

Any way to learn more and understand better?

It is going to depend on how comfortable one is with math' and calculating from formulae. A big part of that is going to depend on how well one was taught at school. It will also depend on how comfortable one is with the terminology used.

I'd suggest taking a step back, telling yourself it isn't that hard and you can do it, then taking each step at a time. When it uses a term you don't know, or understand, stop there and look up what it means and make a note to remind you if needed. With the math', look over the steps one line, or change, at a time and make sure you understand what the calculation was and why it was done before moving onto the next.

If you're still having problems, you may find a beginners book on math' will be a help.

Oh, make sure you start at the start and don't skip any sections of the tutorials.

If you post a link to the actual parts you're having problems with, we may be able to help more directly.

Thank you for the suggestion.

if i want to practice more the formula of ve … where can i find more practical to practice so it will be easy to understand more …

as i can go direct with the car an computer..

I meant basic math' problems and formulae, once you are comfortable with the basic math' it's easy to transition to other math' as numbers are numbers, only the terms (letters) are different.

There should be plenty of math' tutorials on-line, available at your local library, or there may be night classes at your local high school - it's over 30 years since I did calculus at tech', and I recently did night classes as a refresher but the others there were learners.

Have you tried going back to the start of the VE tutorial? Sometimes things make a lot more sense the second time around.


My question is how to calculate the actual air flow, I already know how to calculate the Theorical flow but not the Actual air flow due to the restrictions, so that way I could calculate the real percentage of the volumetric efficiency.

We don't calculate the VE as much as figure out what it must be by adjusting the VE value at a particular condition (load & engine speed) to achieve the requested Lambda / AFR value as measured by a wideband O2 sensor.

If you really did want to calculate the VE, I would suggest you explore various engine simulation programs, given sufficient detail (runner sizes, valve dimensions, piston and head details, and exhaust design), they may be able to produce a VE value for a given condition.

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