Need Info On How To Recalbrate Maf.

[Daboss]

Hey forum whats up? Just need a little help from you guys, in re calibrating a ford lightning maf. I have a z32 maf presently on the car and from logs shows that it is maxed out. I am getting a lightning maf and want to know how do I go about re calibrating the pfc to use it. I have datalogit and a pfc just do not know what to do to re calibrate it for use with the new maf.

Can someone please give me a step by step on how to do this?

[MJTru]

this will be hard man, and not werth the time. well for me that is. I would sell the power fc and get another one. like A d-jetro, but i never went the root as i hate ford. i just got a Haltch PS 2000, and that was fun learning to tune them, and they really don't support Knock which i don't like. other than that they are greate.

Now after the years i lernt to get the GTR L-jetro to run a gtst using the two AFM, and i loved it because i was a FC guru by then (2x Z32). i just got addicted to ani lag. so motec haltech and D-jetro (no anti lag on FC) all the way. You need to change ECU you are making good power and need to swallow the pill and upgrade properly.

[STATUS]

Its easy but best done on a dyno

[Moodles2]

Is the AFM actually maxing out at peak power, or is it just peaking at 5v and maxing out at 4.x volts? You should see a theoretical max of 350kw with a single Z32

I agree that calibrating the AFM needs a dyno, you need to map out the voltage curve (plotting various voltage positions vs the stock AFM at idle, WOT etc) as the PFC doesn't have the specs for lightning MAFs builtin. I've read the VQ maps are close and maybe can be tweaked to suit.

Nistune does have support for lightning mafs though, you might be able to copy the specs and use them for the PFC.

[GTSBoy]

Comparing them in Nistune would be the way to go.

[Daboss]

Is the AFM actually maxing out at peak power, or is it just peaking at 5v and maxing out at 4.x volts? You should see a theoretical max of 350kw with a single Z32

Well according to the pfc log from I hit max boost that surge right before boost settles in I am on load point 20 and from there on load point 19. This is from 4000 rpm until doing a third ger pull from about 2000. 62mm turbo at 25psi. I have not really wot cause I am afraid to lean out and damage the engine. So I am wot until my waste gate yanks opens then about 80% throttle through the rest of the rpm and at tht level on load point 18-19.

I agree that calibrating the AFM needs a dyno, you need to map out the voltage curve (plotting various voltage positions vs the stock AFM at idle, WOT etc) as the PFC doesn't have the specs for lightning MAFs builtin. I've read the VQ maps are close and maybe can be tweaked to suit.

Nistune does have support for lightning mafs though, you might be able to copy the specs and use them for the PFC.

WOW didn't know it was so involved. Thought it was just a simple voltage to load point change. Thought I would just go to point 5 in fc edit change voltages at the rpm points and then tune the injectors to suit.

this will be hard man, and not werth the time. well for me that is. I would sell the power fc and get another one. like A d-jetro, but i never went the root as i hate ford. i just got a Haltch PS 2000, and that was fun learning to tune them, and they really don't support Knock which i don't like. other than that they are greate.

LOL I know the whole import versus domestic thing. See and thats what I am trying to avoid, buying a next ecu, they say the ford afm is good for 700-800whp. Not aiming that high but just want the room for safety and future. With a simple afm rescale car would be able to get to the next level and support the level I am at now. I even heard of a resistor mod and then rescale with the z32 that according to results should theoretically support 1000hp. Again not aiming that high but with safety and future mods in mind this would be a great mod without having to dish 2000 dollrs or so on another ecu.

Now after the years i lernt to get the GTR L-jetro to run a gtst using the two AFM, and i loved it because i was a FC guru by then (2x Z32). i just got addicted to ani lag. so motec haltech and D-jetro (no anti lag on FC) all the way. You need to change ECU you are making good power and need to swallow the pill and upgrade properly.

[paulr33]

to be clear

hitting load point 20 doesnt mean the AFM is maxing out

see if the AFM peaks at 5.0v

if it doesnt, the afm is not maxing out and you need to rescale the load axis - datalogit can do this and a competent tuner can do this

also

if your using a djetro map sensor version what do you think happens when you hit target boost of say 2.1kgcm2?

the map sensor is 3.3v and 2.1kgcm from 4000rpm to redline.... so the load axis never changes?

why because boost never increases

so by changing to a map sensor - you get the same result

[Daboss]

Hey forum sorry to bring up an old thread but I am getting nowhere with trying to calibrate the ford lightning maf to work with my pfc. Is there anyone out there who can give me a tutorial, some info or numbers to put in the pfc to get me started? What numbers do I need to change cause I can not even get it started? If anyone has any idea and was wanting to try and cakibrate one of these meters on a pfc hit me up and let me know what to do/try. All/Any help is appreciated.

[GTSBoy]

I already did. I told you to compare their VQ maps in Nistune.

[Daboss]

I already did. I told you to compare their VQ maps in Nistune.

Yes I saw that but i am in need of more assistance. the trial version of nistune that I have downloaded only stays open for 5 mins or so and that is not enough time to compare all the maps i have to. I need more of a tutorial or for someone who has done it already to share the maps with me or walk me through how to re-scale mine. When I am in fc edit for example and at the maf settings table, the only number I should have to change would be the numbers that are associated with the maf that I am re-scaling right, this would be the chart located at the bottom of the page in fc edit?

[GTSBoy]

I can't see it taking more than 5 minutes to open Nistune, change the VQ table to the lightning one, take a screen shot if you need to, change it to something you can cross reference (like a Z32), take another screenshot if you need to. Job done. I mean, it's just a case of converting voltage to another number.

[Daboss]

I can't see it taking more than 5 minutes to open Nistune, change the VQ table to the lightning one, take a screen shot if you need to, change it to something you can cross reference (like a Z32), take another screenshot if you need to. Job done. I mean, it's just a case of converting voltage to another number.

Hey there thanks for the advice. I crossed referenced the lightning and z32 came up with a couple of numbers and got the car started. Hooray!!!!!!! Just needed that lil push to get it done.

I have another question for you. My idle is a bit funny and I wanted to know if to correct that I need to adjust the voltage or load part of the curve? I tried the load part but it doesn't really seem to make a difference. If I were to adjust the voltage will that in turn make my max voltage less?

[GTSBoy]

Perhaps a 5 second tutorial on how this stuff all works is needed.

1) An amount of air flows over the hot wire. At idle this is a small amount, at various loads it is a larger amount. The AFM outputs a voltage that is directly proportional to the amount of air. When I say "directly proportional", I don't mean that it is exactly linear.....the voltage output and the actual air flow amount are not linearly related, but as the air flow goes up, so does the voltage.

2) The ECU sees this voltage, and because someone worked out what the relationship between air flow and voltage is, there is a map (the VQ map) in the ECU that tells the ECU how much air is flowing based on that voltage. (this is actually slightly simplified, because there is another factor, the "k" factor, that gets involved in calculating the air flow. Perhaps let's just say the VQ map is used to define the shape of the non-linear relationship between AFM voltage and actual air flow).

3) The ECU now knows how much air is flowing, and in combination with a few other inputs (like rpm) can work out what the load on the engine is. That load value is now used to look up the various maps that depend on load for fuelling, ignition, etc.

So you can see that unless the AFM is faulty there is no reason to mess with the ECU's calculations at any point before step 3 in the above list. Steps 1 and 2 are just the physical relationship between real air flow and the AFM's signal to the ECU. You only mess with this stuff if you're desperate. The best thing to do is to tune the ECU's response to that load signal as required. If it's too lean at 50% load, you simply add fuelling at that point in the map. If the idle is fluffy because it's too rich, you take fuel away from the idle part of the map (or, if there is a separate idle map, you work in there).

There is one further complication though, and I'm not sure how this applies to PowerFCs, because I haven't played with them much. The Nissan ECUs have a concept called the k factor which is used to turn the VQ map output into the load signal (known as TP, or theoretical pulse) that is used to look up the maps. If you change the AFM to one that has double the capacity (say) then you need to change the k factor by the same amount to account for the fact that when reading the same voltage, the bigger AFM is sensing double the air flow. There is a similar factor in the PFCs (called injection correction or something similar) that needs adjusting. There should be ample documentation and posts around here to help you out on that score.

**edit. Had to move something I added to the first numbered point down to the second numbered point coz I put it in the wrong spot and it made no sense!

Edited July 1, 2013 by GTSBoy

[Ben C34]

Excellent write up, but took me more than 5 seconds to read