XDF question

[0081(2)]

I have added Fuel used and fuel rate to the XDF im using VY_V6_$060A_Enhanced_v1.0.xdf as i will be changing my injectors and what to have the dash read out correct.

I'm not too sure on what needs to go into the conversion tab. Looking at other items their is a calculation in the expression box. How do you work out that this is ?

Peter

[Jayme]

how did you work out the correct offset to add the items in?

[0081(2)]

I have only added in the below info into the scalars table when you click edit parameter XDF info

Address (hex)
Size
Output Type
Significant Digits

That's about it, i was mostly just comparing info from other tables to help work out what some info should be.

I'm not too sure what you mean with the correct offset, i don't remember seeing that anywhere.
I'm not very experienced with adding items and looking at bin's in hex

[Jayme]

Address. every codebase has different addresses for its items. first you have to know what the address is, then you have to figure out what the data means to figure out the conversion. you cant for example take some tables definitions out of a VS XDF and put them into a VY xdf, you will be editing some random location and produce undesired effects.
there are 2 ways to figure out this info. first, is you disassemble the code, learn how to read it, and by tracing the code, you figure out what you need to know.
second is you find what you want defined in a different codebase, then usually the expression will be the same in other similar codebases. so you can open the two bins in a hex editor and by mathcing surrounding data, you may be able to find where the item you are looking for moved to in the new codebase. most of the time its a stab in the dark and you may have it wrong and be altering who knows what..... the only way to be sure is either try it and go for a drive to confirm your desired effect, or to disassemble and read the code.

adding items to an xdf is not a simple exercise, you may have a steep learning curve ahead!

[0081(2)]

Yep i know that you can copy it over from say a VS to a VY as it will be in different locations, i did a search on the forum and i think it was Yoda that listed the address in the VY bin for the 2 scalars i needed.
It was
0x578A
0x578C
I asked a friend to show me how find these locations in the hex editor. at this point he gave me enough info to be dangerous HAHA..

I originally had the NA injectors and changed to the supercharged V6 injectors and i was just changing numbers directly in the the hex editor and thought i might as well try and learn how to add them into the XDF to make it easier. and i will be going 60s soon and need to update it anyway.

I know the locations are correct but was unsure of the expression, i though i could load a different XDF and see what the expression is in that then apply it to the another XDF and being the injector rate i would have guessed that it was not different between the 2. I was hoping it would no be as hard as disassemble it.

So you need to disassemble it to work out the expression ?

[Jayme]

yes you should be able to get the expression from a VS or later. there is no reason they should have changed it for VY.

but really the expression doesnt matter as much as the value.... you can leave it at X.... increase value and decrease value will still create an effect. the expresison is just there to make it more meaningful. you can just change the value with no expression and see what happens on your wideband if you are really stuck.

[VL400]

It did change a bit as the VT and later models used two things sent to the dash via an ALDL frame, pre VT used an 8bit PWM to the trip computer. VT on there is a fuel used term (sums the injector pulses) and a fuel flow term (instant fuel use).

When getting 11P to talk to the dash I went through the VT code. It looks like the fuel flow calc is based on the target AFR and airflow, knowing that it calculates the fuel flow independently of injector size. There is a constant but it defines some time related conversions to make things easier. Didnt go any further on that as 11P does not have a MAF, so no airflow meant a different method was needed. So there may be something else I missed on that one.

The fuel used is a 1ml/bit sent to the dash used a constant that relates to injecor size though. Flow rate (grams/sec) * 401.35. The TunerPro calc is X / 401.35

[0081(2)]

Thanks VL400

Ill add that to the XDF for fuel used.

Does anyone know what the fuel rate is.