Calling all tuners. VE calcs needed

[KoolBRZ]

I would like to use volumetric efficiency as a goal to optimize my tune for. I need the spreadsheet calculations to return VE from IAT, RPM, MAF g/s, and displacement. Does anybody know what these calculations are to solve VE. I would like to run VE for entire logs to determine which parts of my AVCS mapping are working better, and which parts aren't working as well. A dyno run only shows the performance of the far right column of cells, since it's just full throttle till redline. I need to be able to rate part-throttle performance to fix all the bugs in my mapping. Calling the experts, @Td-d, @Kodename47, @steve99, @Wayno, and anyone else I forgot to mention.

[vgi]

Originally Posted by KoolBRZ

I would like to use volumetric efficiency as a goal to optimize my tune for. I need the spreadsheet calculations to return VE from IAT, RPM, MAF g/s, and displacement. Does anybody know what these calculations are to solve VE. I would like to run VE for entire logs to determine which parts of my AVCS mapping are working better, and which parts aren't working as well. A dyno run only shows the performance of the far right column of cells, since it's just full throttle till redline. I need to be able to rate part-throttle performance to fix all the bugs in my mapping. Calling the experts, @Td-d, @Kodename47, @steve99, @Wayno, and anyone else I forgot to mention.

you can try this, there is a ve tab:
http://www.romraider.com/forum/viewt...34e2ca7c354377

although, i have not used it myself I created the tab based on a request, according to the feedback it works as expected. if you do use it - read the how to guide, i've tried to cover it as fully as possible.

[KoolBRZ]

Originally Posted by vgi

you can try this, there is a ve tab:
http://www.romraider.com/forum/viewt...34e2ca7c354377

although, i have not used it myself I created the tab based on a request, according to the feedback it works as expected. if you do use it - read the how to guide, i've tried to cover it as fully as possible.

Went there, tried that. It's not what I'm looking for. I found an easy to use website, http://www.otctools.com/ve, but I want to run calcs for VE down entire logs. That tool is way too hard to use for VE. All I need are the equations to solve for VE from IAT, RPM, MAF g/s, and displacement. I can then copy the equation for the whole column and get a VE column beside the rest of the log stats.

[Kodename47]

What I use:

VE=PRODUCT((MAF/((MAP*100000)/(287.05*(IAT+273.15))*1000))/(121.9254*RPM/3456*0.0283/60)*100)

MAF is in g/s (Any change in MAF scaling will mean non-comparable results)
MAP is in Bar (convert if in psi or kPa)
IAT in Celsius

[vgi]

Originally Posted by KoolBRZ

Went there, tried that. It's not what I'm looking for. I found an easy to use website, http://www.otctools.com/ve, but I want to run calcs for VE down entire logs. That tool is way too hard to use for VE. All I need are the equations to solve for VE from IAT, RPM, MAF g/s, and displacement. I can then copy the equation for the whole column and get a VE column beside the rest of the log stats.

sorry, i was leaving and didn't read carefully.
there is a bunch of various formulas and spreadsheets for VE calcs.
I have an SS with formula Kodename47 mentioned above.

Here's some RR threads you might want to check:

http://www.romraider.com/forum/viewt...hp?f=32&t=9168
L 2 * R * T 273.15 + * P D * 28.97 * / 100 *
D = Engine displacement in format x.x ex.2.0
L = Engine load (calculated) in format x.x ex.1.0
T = Intake air temperature in celsius
P = Manifold pressure ...depending on which units you use you will have to change the value R accordingly.
R = ideal gas constant. Dependent on the MAP units used -> R = 1.205912 (MAP in psi), R = 0.08314472 (MAP in bar), R = 8.314472 (MAP in kPa), R = 62.363669 (MAP in mmHg)

the above VE formula is an RPN notation, in infix it is:
(L * 2 * R * (T + 273.15) / (P * D * 28.97) * 100)


http://www.romraider.com/forum/viewt...hp?f=32&t=2546
MAP = MRP + P_atm
P_atm is the actual atmospheric pressure and entered in a box in the spreadsheet.
densitySTP = 1.2 kg/m3 = 0.0012 g/cc at 14.7 psi and 70F
displacement = 2457 cc for 2.5liter boxer engine
load is defined for one revolution of the engine which is 2 combustion cycles out of 4 cylinders
load_theoretical = (MAP / 14.7) * densitySTP * displacement * (1/2)
VE = actual load / load_theoretical
MAP = MRP + P_atm where P_atm = actual = 12.2 psi. I kept the 14.7 in the denominator since that is for the conversion from STP.

[KoolBRZ]

These are great examples, but they are too good. The website I quoted in the first post is able to solve VE using only the IAT, RPM, g/s, and displacement. No, it isn't going to be as accurate, but it works with Fahrenheit temp, and yet uses liters in displacement. If I only had their formula, this could be an easy, quick, and dirty calc to show power fluctuations across the tune caused by incorrect MAF scaling and incorrect AVCS table values. It can also be used to find the sweet spots where RPM and AVCS tuning get the best performance from the Intake/Exhaust components.

[KoolBRZ]

I'm trying to find the equations to do exactly what the widget on this website does. "http://www.otctools.com/ve" It calculates VE from only IAT, (in Fahrenheit), RPM's, MAF g/s, and displacement, (in Liters). I don't need to be real-world comparable, with various compensations to compensate for altitude, ambient temperature, humidity, Octane, or any other compensation, since I'm only using it to compare cells WITHIN the same spreadsheet log. I want to use it to find the VE sweet spots where resonance helps create better VE and expand on those as much as I can, and I want to find the problems spots within the log where VE suffers because of MAF scaling, or AVCS mapping is off. I just need a quick and dirty equation I can use in my logs to determine which lines have better VE, and which lines have worse VE, so I can use trial and error to find out why.

[phrosty]

Originally Posted by KoolBRZ

I'm trying to find the equations to do exactly what the widget on this website does. "http://www.otctools.com/ve" It calculates VE from only IAT, (in Fahrenheit), RPM's, MAF g/s, and displacement, (in Liters). I don't need to be real-world comparable, with various compensations to compensate for altitude, ambient temperature, humidity, Octane, or any other compensation, since I'm only using it to compare cells WITHIN the same spreadsheet log. I want to use it to find the VE sweet spots where resonance helps create better VE and expand on those as much as I can, and I want to find the problems spots within the log where VE suffers because of MAF scaling, or AVCS mapping is off. I just need a quick and dirty equation I can use in my logs to determine which lines have better VE, and which lines have worse VE, so I can use trial and error to find out why.

var dAirDensity = (iat + 459.67) / 491.67 * 0.0808;
var actualVolumetricFlowRate = (maf * 0.0022 * 60) / dAirDensity;
var theorecticalAirFlow = (engineLiters * rpm * 61.01) / 3456;
var volEfficiency = (actualVolumetricFlowRate / theorecticalAirFlow) * 100;

or...

7.47733158498607*maf/(engineLiters*(0.000164337868895804*iat + 0.0755411881953343)*rpm)

[KoolBRZ]

Originally Posted by phrosty

7.47733158498607*maf/(engineLiters*(0.000164337868895804*iat + 0.0755411881953343)*rpm)

Thank you. Is that in Fahrenheit, or in Celsius?

[Kodename47]

The one I posted only has MAP added over your list, is that really much of an issue? Its also dead easy to paste in as that's copied direct from excel.

[KoolBRZ]

Originally Posted by Kodename47

The one I posted only has MAP added over your list, is that really much of an issue? Its also dead easy to paste in as that's copied direct from excel.

I haven't been logging MAP, so I wouldn't be able to use it on my old logs. It's also in celsius.

[ztan]

Not a widget, but if you use MatLab, you can dump in all your data calculate VE based on any load/RPM:
http://www.ft86club.com/forums/showp...0&postcount=12

[burdickjp]

Originally Posted by KoolBRZ

I haven't been logging MAP, so I wouldn't be able to use it on my old logs. It's also in celsius.

I dont think you're going to get VE without map. Ideal gas law requires it.

[KoolBRZ]

Originally Posted by Kodename47

What I use:

VE=PRODUCT((MAF/((MAP*100000)/(287.05*(IAT+273.15))*1000))/(121.9254*RPM/3456*0.0283/60)*100)

MAF is in g/s (Any change in MAF scaling will mean non-comparable results)
MAP is in Bar (convert if in psi or kPa)
IAT in Celsius

I used the following equation only. "=PRODUCT((MAF(g/s)/(((MAP(PSI)*0.0689475729)(BAR)*100000)/(287.05*(((IAT(Fahrenheit)-32)*5/9(Celsius)+273.15))*1000))/(121.9254*RPM/3456*0.0283/60)*100)" Rather then convert Fahrenheit to Celsius, and PSI to BAR in separate columns, I included it all in one long equation.