VE Editor Numbers...What do they mean?

[old66tiger]

Poking around in the VE editor and it does not look anything like I have seen in a variety of videos on line. I have engine speed and manifold pressure. The numbers in the cells range from -132 on the very upper left corner to numbers in excess of 2500 for a variety of cells. The VE table in my ECM looks identical to a stock tune VE table. What units are these numbers in and how do they relate to other variables in the ECM? Thanks...

[schpenxel]

Post the tune you're looking at

Gen 3 vehicles used more of a 'conventional' VE table/value which was literally just a percentage of cylinder filling. So if you had a 1 liter cylinder and on the intake stroke it was pulling in 0.5 liters of air then the VE would be 50%. From there it could factor in things like how large the cylinder was and the temperature of the air that went into the cylinder to figure out how much oxygen is in the cylinder.

Gen 4 vehicles went ahead and multiplied a few other things into their "VE" table, so that is why the numbers look so weird. It's been dubbed "GMVE" to differentiate it from ordinary VE that gen 3's use.

Gen 4's "VE" values are conventional VE * cylinder volume / R --> "GMVE = CYLVOL * VE / R"

This simplifies a few steps for the computer, so instead of having to multiply "VE" by Cylinder volume constantly, it's already factored in.

So, that's pretty much how the units work.

Bottom line it's a way of estimating how much air is going into the engine without actually measuring it. All you need to know is RPM and MAP and with a volumetric efficiency value you can figure out how much oxygen is in the cylinders. If you know how much oxygen is in the cylinders and you know the air fuel ratio that you are after, then calculating how much fuel you need to inject is a simple enough calculation

Hopefully that is what you were asking?

This blog has some pretty good examples of how the math works if you're into that kind of thing

http://redhardsupra.blogspot.com

[rjw]

Interesting article

I can find dynair, but not dyncylair only cyl airmass??

thoughts

thx

[schpenxel]

Cylinder airmass can be calculated several different ways depending on the setup

You can use the math parameter below to calculate cylinder airmass based on dynamic airflow. IMO this is one of the better ways to do it because dynamic airflow will be accurate whether you're using the MAF or in SD or both..

Or if you're using the MAF you can just use the built in MAF Cylinder Airmass that comes with HPT

Dynamic cylinder airmass:

[2320.71]*(120/8)/[50070.56]

This formula works on gen 4's but I haven't tried it on a gen 5, so it may need a little tweaking. 2320 is dynamic airflow, 50070 is RPM's

[rjw]

Cylinder airmass can be calculated several different ways depending on the setup

You can use the math parameter below to calculate cylinder airmass based on dynamic airflow. IMO this is one of the better ways to do it because dynamic airflow will be accurate whether you're using the MAF or in SD or both..

Or if you're using the MAF you can just use the built in MAF Cylinder Airmass that comes with HPT

Dynamic cylinder airmass:

[2320.71]*(120/8)/[50070.56]

This formula works on gen 4's but I haven't tried it on a gen 5, so it may need a little tweaking. 2320 is dynamic airflow, 50070 is RPM's

what do the .71 and .56 mean ?

thx

[schpenxel]

what do the .71 and .56 mean ?

thx

Denotes what unit you want the parameters to be in. So 2320.71 is dynamic airflow in g/sec. .72 would be in lb/hr, .72 is lb/min, etc.

[rjw]

Denotes what unit you want the parameters to be in. So 2320.71 is dynamic airflow in g/sec. .72 would be in lb/hr, .72 is lb/min, etc.

I know that I've found this somewhere in the scanner, but forgot where???? link?

thx

[schpenxel]

Tools-->quantities and units (or hit ctrl+q)

Or when you're creating a math parameter you can click somewhere inside [2320.71] and hit edit variable and select whatever unit you want

[rjw]

Tools-->quantities and units (or hit ctrl+q)

Or when you're creating a math parameter you can click somewhere inside [2320.71] and hit edit variable and select whatever unit you want

Is there a master list somewhere of these parameters and corresponding numbers?

thx

[schpenxel]

I hope you're kidding

[rjw]

I hope you're kidding

did I miss the boat? Is there one already?

thx....yes, I am dumb

[schpenxel]

The units list I told you how to get to in the previous post

There's no reason to have a list of the parameters themselves in a list by # format like I think you're thinking. V3 has a parameter selector built in where you can just type in the name of whatever you want and it'll show you your options. Some of them are different for different vehicles so any kind of list would be huge

[rjw]

The units list I told you how to get to in the previous post

There's no reason to have a list of the parameters themselves in a list by # format like I think you're thinking. V3 has a parameter selector built in where you can just type in the name of whatever you want and it'll show you your options. Some of them are different for different vehicles so any kind of list would be huge

sometimes I see a number and a sensor above, but when going to the list, not sure when there are 5 with the same name followed by sae, A,B,C,D,engine, generic or whatever

works well going one way but not so well going the other...if that makes sense?

In the channels, items already selected are highlighted...not in the parameters list??

[schpenxel]

Yeah that's more common on gen 5's for some reason.. not sure why there are all the different A, B, C, etc. But HPT is just reporting everything we have to work with..

The sensor ones are usually more universal so most of the time I use those

Yes, channels list will have everything you're already logging highlighted. Parameter selector you'll want to hit the gear w/green check mark icon to filter it down to only show stuff you can actually use

[rjw]

Yeah that's more common on gen 5's for some reason.. not sure why there are all the different A, B, C, etc. But HPT is just reporting everything we have to work with..

The sensor ones are usually more universal so most of the time I use those

Yes, channels list will have everything you're already logging highlighted. Parameter selector you'll want to hit the gear w/green check mark icon to filter it down to only show stuff you can actually use

I really appreciate all your help. I wasn't bad 10 years ago in v2 gen 3, but at the immediate moment, I'm going thru brain overload

thx again

[schpenxel]

Yeah that's a big jump. I'm going to have to make the leap to gen 5's too at some point.