MAF Info

Disassembly, Reassembly, Tools and devleopment. Going deep with Hardware and Software.
Post Reply
yoda69
Posts: 1215
Joined: Sun Mar 15, 2009 10:20 am
cars: 2004 VYII Acclaim Wagon V6 Auto LPG/Petrol
2004 VYII Berlina sedan V6 Auto
2005 VZ Monaro CV8 manual
Location: Geelong, VIC

MAF Info

Post by yoda69 »

I've been having a bit of a look at trying to work at the MAF info from some BIN's.
Looking at several that have the 8 tables and the scalars I think the following maybe correct.
For each MAF Table there are 12 bytes of data, ie
02 C2 05 00 13 2A 44 61 81 A4 C9 F0 (MAF Table 1 from CNPF, $4D44-$4D4F)

The first 2 are MSB LSB, ie combine to $02C2 which converts to 674 Decimal.
This value is then divided by 256 which gives us 674/256=2.6328

The next one is a single byte, $05 which converts to 5 Decimal
This value is then divided by 256 which gives us 05/256=.019531

grams/ sec = (0.019531 * X) + 2.6328

While this didn't work with the delcowizzids $A6 MAF tables (which area a work inprogress, I think they may need updating), it does work with a $5B5.xdf and AZKT calibration.
Refer attached spreadsheet for calculations I used.

Would appreciate any feedback (good or bad) on this info.

Thanks,
Greg
Attachments
MAF Calculation Info.rar
Updated
(12.66 KiB) Downloaded 528 times
Last edited by yoda69 on Sun Aug 23, 2009 9:05 pm, edited 1 time in total.
User avatar
delcowizzid
Posts: 5493
Joined: Sat Feb 28, 2009 8:38 pm
Location: Wellington NZ
Contact:

Re: MAF Info

Post by delcowizzid »

nice info mate yeah never trust anything i come up with LOL maf tables could be way out in my xdf ive never had to use them to see if they even do anything or what they are supposed too do i based them off the VS xdf i had when i was making the vt xdf they ahve the same figures as the VS maf bins in there i know that much thats how i found them in the first place
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem
yoda69
Posts: 1215
Joined: Sun Mar 15, 2009 10:20 am
cars: 2004 VYII Acclaim Wagon V6 Auto LPG/Petrol
2004 VYII Berlina sedan V6 Auto
2005 VZ Monaro CV8 manual
Location: Geelong, VIC

Re: MAF Info

Post by yoda69 »

That's alright, it pointed me in the right direction, I was trying to find them for the $A5 VT bin, in CJKU they start at $4FC0 for the first table value. Sorted out my problem with TunerPro, didn't have the size of the bin specified, ie.$20000. All appears OK, will just have to figure out a few more tables. Will update the file in the first post a little later with some additional info.
yoda69
Posts: 1215
Joined: Sun Mar 15, 2009 10:20 am
cars: 2004 VYII Acclaim Wagon V6 Auto LPG/Petrol
2004 VYII Berlina sedan V6 Auto
2005 VZ Monaro CV8 manual
Location: Geelong, VIC

Re: MAF Info

Post by yoda69 »

OK,I've updated the file at the start of this thread, there are 2 sheets in an Excel spreadsheet.
The first one is my ramblings of trying to figure it out, and the second oone is populated with VT V6 MAF info from CJKU/CJKW.
At the bottom is a calculation showing the % difference between the end of one MAF Table and the start of the next, the highest difference was 0.17% so it looks good.
If people are playing around with the MAF values, it would be good to check this, as if the gap between tables is large I think most people can envisage the problems.

OK, of to bed for me and will have a look for some more VT $A5 tables during the week, well more defining the tables, I've found a lot, just don't know what they all are yet.
User avatar
antus
Site Admin
Posts: 8253
Joined: Sat Feb 28, 2009 8:34 pm
cars: TX Gemini 2L Twincam
TX Gemini SR20 18psi
Datsun 1200 Ute
Subaru Blitzen '06 EZ30 4th gen, 3.0R Spec B
Contact:

Re: MAF Info

Post by antus »

good to see someone working on the newer bins, keep up the good work! :thumbup:
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
Post Reply