RomRaider

After using a couple VE logger definitions i got from here I noticed the accuracy just wasnt there, like spikes to over 100% efficiency on decel or whenever I let off the throttle.I was trying to tune my AVCS using these loggers and was just going in circles.I now use virtual dyno and my new VE logger definition .IMO this is alot closer to real VE .First I'd like to say sorry if someone has already done this and feel free to delete this thread if so.

I was reading the AP speed density help document as I own one and was thinking of going SD.I read how they calculate their VE and they were nice enough to print thier equation.That equation is VE= (load*2*R*IAT/MAP*Displacement in ltrs*MMA)*100 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).MMA = Molar Mass of Air Constant =28.97 g/mole.Using this equation I made a logger definition for VE .

I figured if its good enough to use to tune SD and make a VE table out of then its good enough to see what changes AVCS values make.Oh this is for 2.0 liter engines .added one for 2.5 also .Questions or comments please feel free to post

Please when you download please return and let me know how its working.For me it works awesome I want to make sure it works the same for everyone else.If it doesnt ill take it down .Thanks......

Can you post rpn for ve formula posted above? Will use it for Kline/can logging.

rpn?

Reverse Polish Notation

yeah i was just about to ask if thats what he meant .Because most ppl dont ask for reverse polish notation just thought it was wierd lol .one sec and ill get it up but really all you need is there in first post .but ill put it up in a sec anyway.

If people can validate the calculation and are happy with its results I'll incorporate the 2.0L & 2.5L VE parameters into the official logger.xml

BTW: this was another calculation offered.where 2457 is the displacement in cc.

Ty dshultz.The one you posted was from freon right?It works ok but has huge spikes and reads a little high compared to true ve.I think this is closer to true ve IMO.

MFB..Do you really want RPN if so i need to know how you log temp and pressure in what units.Romraider uses infix notation which is "(P200*2*8.314472*([P11:C]+273.15))/([P7:kPa]*2.5*28.97)*100" .If you really want RPN I will make you one but Ill need to know the above info and I guess youll have to plug in your data for every line of your log ...Seems like alot of work but Ill make one if you really need it in RPN...Thanks again everyone

He probably wants it in rpn to use it with the standalone logger feature of the openport 2.0

From here: viewtopic.php?t=8054


Just post the RPN with name_units variable items that you need logged in addition so the calculation can work.
Then anyone can add those name_units log items themselves.

Ok here is the RPN for the formula Im using

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)

Please test and leave feedback I believe the above equation is correct.

Has anyone validated this def? Seems like a good idea to me if it works.

These VE calc parameters are in the official Logger def.
viewtopic.php?t=1642&start=1

Can someone confirm that this is correct for 2.1 stroker?

I am going to use stock maf and injectors to build VE table with this current 2.1 stroker engine. So should I change the volumetric efficiency parameter to match the 2.1 to get the most accurate reading? Thanks in advance.