Efficiency Point of a MAF-based system

Discussion and support for MoTeC's previous generation of entry level ECUs

Efficiency Point of a MAF-based system

Postby Vassili Wang on Mon Nov 14, 2011 2:38 am

Hello.

My car has a 4-stroke engine with four cylinders. And I want to use a MAF sensor.

In "help", "Efficiency Point = MAF / inductions per rev / (RPM/60) * 100"

I'd like to know what does " inductions per rev " mean ? For my engine, it should be 0.5 or 2 ?

Thanks a lot.
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Re: Efficiency Point of a MAF-based system

Postby Holmz on Mon Nov 14, 2011 5:15 pm

Vassili Wang wrote:Hello.

My car has a 4-stroke engine with four cylinders. And I want to use a MAF sensor.

In "help", "Efficiency Point = MAF / inductions per rev / (RPM/60) * 100"

I'd like to know what does " inductions per rev " mean ? For my engine, it should be 0.5 or 2 ?

Thanks a lot.



2-stroke = 1.0
4-stroke = 0.5

(I suppose, by induction, a 1/2-stroke would be 2 or 4)
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Re: Efficiency Point of a MAF-based system

Postby Scott@FP on Tue Nov 15, 2011 8:03 am

It works out to grams air per induction * 100, regardless of cylinder count or size or 2 or 4 stroke. Determined by Gen setup/main setup/# of cylinders, 2 stroke or 4 stroke. If you have a properly calibrated MAF sensor and known injector properties the fuel table can be pretty accurately calibrated without running the car.

Your actual 100% VE point depends on engine size and cylinder count, and 1 L of air is approx. 1.2g. So for a 4 cycle 2 liter engine actual 100% VE will be in the approximately 60% Eff area (.6g of air per induction).
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Re: Efficiency Point of a MAF-based system

Postby MarkMc on Wed Nov 30, 2011 4:22 pm

Inductions per rev.......how many firings for one revolution of the crank. For a 4 cylinder 4 stroke engine it would be 2.
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Re: Efficiency Point of a MAF-based system

Postby Vassili Wang on Thu Dec 01, 2011 1:37 pm

MarkMc wrote:Inductions per rev.......how many firings for one revolution of the crank. For a 4 cylinder 4 stroke engine it would be 2.

Thanks a lot!!
Vassili Wang
 
Posts: 10
Joined: Thu Mar 10, 2011 11:39 am


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