Volumetric Efficeincy

Does anyone know what the number is for the Mirage?

It varies with RPM. Where you make your most torque is when you have the highest volumetric efficiency. Its likely in the mid 90s I'd guess at peak torque.

I guess I would be looking at around 2500rpm as that seems to be the happy spot for the engine. Trying to get Torque to give me the most accurate fuel flow rates possible. I think the default number is .83 or .85, I figured we have to be better than that but even after reading up on how to calculate it, I think I don't have all the info needed. Sadly Mitsubishi does not give the info in the specifications. I'm also trying to figure out the usefulness of the engine load reading as it relates to fuel economy.

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Originally Posted by 2015 Floyd

Sadly Mitsubishi does not give the info in the specifications.

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I would expect the MIVEC variable valve timing would change the VE number not just with engine speed but with load, no?

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Originally Posted by 2015 Floyd

I'm also trying to figure out the usefulness of the engine load reading as it relates to fuel economy.

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I wonder the same thing because my app shows very low horsepower numbers. I think it might be helpful when trying to achieve low fuel consumption.

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Originally Posted by Eggman

I would expect the MIVEC variable valve timing would change the VE number not just with engine speed but with load, no?

I wonder the same thing because my app shows very low horsepower numbers. I think it might be helpful when trying to achieve low fuel consumption.

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Yes, at lower engine speeds, MIVEC intentionally closes the exhaust valves early in the exhaust stroke and opens the intake valves less to intentionally reduce cylinder filling (volumetric efficiency). As a result, more exhaust gas from the last combustion stroke remains in the cylinder. This helps to save fuel by decreasing the effective displacement of the engine and reducing pumping losses.

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Originally Posted by alvinkiang

Yes, at lower engine speeds, MIVEC intentionally closes the exhaust valves early in the exhaust stroke and opens the intake valves less to intentionally reduce cylinder filling (volumetric efficiency). As a result, more exhaust gas from the last combustion stroke remains in the cylinder. This helps to save fuel by decreasing the effective displacement of the engine and reducing pumping losses.

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I've heard about this. I also understand that this can effectively act as an EGR (exhaust gas recirculation.)

Maybe I'm wrong, but I thought the Mirage MIVEC was on the intake only and the exhaust was fixed.

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Originally Posted by Eggman

I've heard about this. I also understand that this can effectively act as an EGR (exhaust gas recirculation.)

Maybe I'm wrong, but I thought the Mirage MIVEC was on the intake only and the exhaust was fixed.

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Yes, you are correct. The different variations of their cam timing systems may be found here:

http://www.mitsubishi-motors.com/en/...ary/mivec.html

The 3A92 mirage setup is found on that page. Intake valves only.