Primary Ignition Load MAF mode

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sweet_baby_james
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Primary Ignition Load MAF mode

Post by sweet_baby_james »

I've taken some time away from my turbo two-stroke project, finally getting back into in now with a MAF setup. I have the Primary Ignition Load set to MAF with a 650g/s MAF range selected (this is a 350cc motor, MAF is good for up to 400g/s) . In the Ignition Table 1 the y-axis is labeled 'ignload MAFload' and the bins defaulted as 20.1 to 100. Are these bins a % of the max range of the MAF sensor? In this case, the bins would be % of 650g/s? I have attached a picture of the table.

I haven't been able to find many posts where people are using MAF as the igntion load, even when MAF is used for fueling. Is it not common to use MAF for ignition load?

Thanks

James
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sweet_baby_james
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Re: Primary Ignition Load MAF mode

Post by sweet_baby_james »

Maybe there are fewer people using MAF ignition load than I thought! I still have a MAP sensor connected so should I run SD ignition load?

James
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whittlebeast
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Re: Primary Ignition Load MAF mode

Post by whittlebeast »

My bet is you are off in some uncharted water in the ignition side of things. I wish I could help.

Andy
sweet_baby_james
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Re: Primary Ignition Load MAF mode

Post by sweet_baby_james »

Sure seems that way. So do I assume the people running MAF for fuel are running SD for ignition load? Wondering what would be best for a 2-stroke application.

James
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whittlebeast
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Re: Primary Ignition Load MAF mode

Post by whittlebeast »

My bet is MAFload would be best but I have no clue what the advance table needs to look like in the field.
sweet_baby_james
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Re: Primary Ignition Load MAF mode

Post by sweet_baby_james »

I have the ignition advance vs RPM that I got from the original service manual. In terms of how the MAFload should affect the advance is anyones guess. The table I posted above represents what I got from the service manual.
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Matt Cramer
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Re: Primary Ignition Load MAF mode

Post by Matt Cramer »

MAF load is the measured airflow divided by the theoretical airflow at 100% VE and 100 kPa intake pressure at your current RPM. The number is very similar to a MAP sensor reading.
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wrenchdad
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Re: Primary Ignition Load MAF mode

Post by wrenchdad »

I have been running MAF for both fuel and spark loads for a while, my car has ITBs so using my MAP sensor would not be reasonable.

No issues with this setup. It's on my daily driver.

Hope this helps, later wd
sweet_baby_james
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Re: Primary Ignition Load MAF mode

Post by sweet_baby_james »

Matt Cramer wrote:MAF load is the measured airflow divided by the theoretical airflow at 100% VE and 100 kPa intake pressure at your current RPM. The number is very similar to a MAP sensor reading.
Ok thanks. So the Y-axis is a % value based on the engine parameter that have been defined? If anyone can provide the calc from the code that might help me understand a little more.

Thanks
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Matt Cramer
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Re: Primary Ignition Load MAF mode

Post by Matt Cramer »

The Y axis value is calculated based on the engine size parameter. You can think of the number as this:

(How much air your engine should flow at that RPM if it's naturally aspirated) / (How much air it's really flowing)
Matt Cramer -1966 Dodge Dart slant six running on MS3X
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