hondafan

iTrader: (25)

i tried that per your instructions in another thread, the only problem is that my Eflash! base map hig/low octane ignition maps are so close(1 degree difference most places)that it's hard to tell. all i have to log is a palm OBD-II logger and i don't think it logs knock like evoscan which i can't use since i don't own a laptop. any other way to tell? there is obviously no direct correlation between load and boost pressure? any estimates for load at certain rpm's would be appreciated, i'm not even sure which ones i should be around, like a ballpark figure for running around 20-21 psi?

kf6ytc

iTrader: (10)

load is load, it's the same here with the exception that our cars have boost. MAF/MAP the load vs rpm is the same.

The load % closely relates to kpA...

Did you read this ? https://www.evolutionm.net/forums/sh...d.php?t=201146

cpoevo

iTrader: (1)

That is nto totally correct. Our load is based on a few calculations to figure load since we dont use a MAP sensor. It uses a combination of MAF frequency, air temp, and some other calculations. The load columns are more or less generalized and not exact. You should be close though.

hondafan

iTrader: (25)

so let's say you're maxing out the stock turbo, you're chart only shows to 23 psi?

JohnBradley

iTrader: (30)

It will only calculate up to 23 psi on a non-rescaled map. If you run 30 it is still giving fuel and spark based on the 260% load cell. With an 8 you can rescale and get that number to 300 (well more if you want its a matter of compromise), the IX is 300 out of the box and can be rescaled higher yet (with less compromise).

hondafan

iTrader: (25)

when you do this does it take away lesser load cells to compensate for adding the higher ones thereby lessening the map resolution? also, how do you rescale for the higher load cells?

Ludikraut

iTrader: (17)

It's virtually impossible to tell which load cells you are hitting with an e-flash due to the large number of equal timing cells. Furthermore, if you only have an OBD-II logger, then you'll have to find a way to correlate airflow (lb/min or g/sec) to the Load columns.

l8r)

kf6ytc

iTrader: (10)

The load % closely relates to kpA...

bhcevo

Since the MAF measures directly the MASS of airflow per second, it doesn't seem that any temperature correction should be necessary for the load calculation.

You need temperatures corrections when you want to go from a volume measurement to a mass measurement (typically for a gas). Course you also need em for other things too...

Load should be something like number of oxygen molecules that combust in the cylinder during the power stroke.

To get that you take mass airflow per second, divide by engine speed to get mass airflow per revolution. Multiply by the appropriate constants to go from mass air to numer of oxygen atoms. One crank revolution multiplied by 4 cylinders * 0.5 power strokes/crank revolution equals 2 power strokes, so divide by 2 and you get oxygen atoms/power stroke. Wallah!

Man, this is easy. Mitsu should fire their ecu engineers and hire me instead. Hehe.

Ah well...there might be a noticeable temperature dependence for some of these other factors. Just wanted to point out that MAF measures mass directly which is way cool, and also eliminates the need for that particular temp correction.

kf6ytc

iTrader: (10)

Correct me if I am wrong, but kPa is a measurement of pressure. If you take a close look at the fuel tables, I think it would be safe to assume 10-90% load is vacuum, 100% is atmospheric pressure and 101%+ is boost. The load on my stock rom goes to 260% which is about 23 psi... I think it's safe to assume that although the load % is not directly related to manifold pressure it is pretty close, and may have actually been designed to correlate to kPa.


Please correct me if i'm wrong as i am a n00b to ecuflash/tuning.

TJ

MalibuJack

iTrader: (5)

You are roughly correct.. HOWEVER that is only for a stock ECU and Stock car.. Anything that alters the MAF reading throws those values off a bit, but they are a good starting point.. It really goes out the window when you go to a different turbo, in my case 15psi puts me in the 260% sites... But the more you do it, the more you get comfortable with what your car does and where to look.

nj1266

iTrader: (6)

The pocket logger does have a calculated load pararmeter that it logs. I do not know if it corresponds to the load in the ECU table. But the pocket logger was created by DSM/EVO guys so maybe it is the same load.

"Calculated Load:

Range: 0 to 100%
Technically, Calculated load is current airflow divided by peak airflow, where peak airflow is corrected for altitude (barometric pressure). Peak airflow is typically represented as the maximum theoretical airflow possible or is calculates as a function of engine RPM.


load = (Current Airflow/(peak airflow @ sea level))*(Sea level atmospheric pressure/Barometric pressure)*100% Basically it's exactly as it's labeled. It tells you how much load is on the engine. In super simple terms its throttle position corrected for RPM, gravity (hill) and drag (wind, rolling resistance, towing a trailer)."

hondafan

iTrader: (25)

i know that i can log MAF hz, would i be able to find the load cells i'm in using this value?

l2r99gst

iTrader: (2)

The Mitsubishi Karman Maf sensor does NOT measure mass airflow. Mass airflow is calculated by the ECU via the frequency of the MAF sensor, temperature, and baro.

You may be thinking about a GM hotwire MAF, which measures mass airflow directly.


Eric

bhcevo

My bad. The Karman-Vortex style MAF sensor output is indeed proportional just to the airflow, and not the mass airflow. As you say, the temperature correction is needed to get mass. I take back what I said earlier.

Assume gas mass is still inversely proportional to Temp in a moving airstream. Assume the load tables are normalized say to 300 K (room temp), then the correction takes into account any deviations from 300 K.

Using standard first order error propagation techniques, the percent change in n, or mass airflow, or load, is roughly equal to the percent change in T from 300K. The biggest swings your temps will see are a few tens of kelvin, say 30 K.
So 30 K/ 300 K is 10%. So your load value could be up to 10% off WITHOUT a temp correction. 10% of 240 is 24, which is basically one entire column up or down.

Seems likely that the lack of a temp correction could throw your calculated load off by up to one column no problem. Probably not more than that.