How does a C&L Maf work on our cars?

rj95svt · Jul 24, 2007

I've always thought that when you know how things work then when things go wrong you can better know how to troubleshoot and fix the problems but, sometimes there is no way to learn like practical experience. I hope that the learning curve is not near as steep since I'll be armed with atleast basic knowledge of the CBAZA EEC IV.

final5-0 · Jul 24, 2007

rj95svt said:
I've got another question about this. If the stock 94-95 mustang GT makes only around 180 rwhp and the stock meter will work well all the way to somewhere around 300 hp aren't we only using 2/3 of the stock maf's curve in stock form. I would think that the there woundn't be a lot of difference between the two scenarios.

Very good point

I went back as far as I could with my old dlogs.

I could not find any with a stock setup. The oldest dlogs I could find
were with my self ported E7 combo.

Way back then ... the CalCon software (V1.18) gave maf data in a kinda
funky value
I just couldn't remember what was what with it

It would be great to hear from other members about how much of the
curve a stock or close to stock Stang uses

Maybe Greg, Wes or some of the others will offer some insight

Additionally I hear that the lightning maf has a better resolution than the stock mustang maf. I have no practical experience with these so I'm only working with what I've read, but if that's so wouldn't there be a possibility to get better than stock like driveability using one of these meters?

I haven't seen anything along those lines

Grady

final5-0 · Jul 24, 2007

I would like to point out something about this particular thread.

I've been involved in lots of these maf/inj threads over the years

Its a subject that can be a bit intimidating

This one has seen some of the best discussion IMHO

I know I ain't got all the answers ... thats for sure
but
I see this thread has been more productive simply because .....

We got some peeps here who are not shy about seeking answers
on this public forum.

On a personal note

That is so encouraging to me

On a public forum ... Well ... Some might not wanna say they don't
understand or know all about something.

I have always enjoyed helping my Stangnet friends when I can

One of my biggest fears has been
I might be seen by some as ... a kind of know it all guy

I did not want to somehow or the other project an attitude
that would make some not feel free to get involved
in threads such as this one

I can only see this happening as an indication of ......
Peeps feel comfortable here

Personal note ... over

Sorry for getting kinda sappy and all that
but
I just had to say it ... I reckon

Grady

rj95svt · Jul 24, 2007

I enjoy these type threads as it can get very intresting. As far as the lightning maf I remember reading about it having better resolution on that other large mustang forum but I'm unsure about that as well. It's certainly not out of the relm of possibility being that with newer technology cars are producing better power with better driveability and durability every year.

Thanks for the words of encorougment ( I can't spell sometimes) on my new adventure I'm about to embark on in the world of self tuning I got a feeling that I am gonna learn alot before to long.

blksn955.o · Jul 24, 2007

Honestly I have not seen any logs from a Pro-M with 19's so maybe there is something with how there "foolery" works. So yeah, maybe with 19's there is not that much diff. from the stocker...I would still think they would flow at least alittle more than the stocker.

With my fairly mild combo I was really close to pegging my stocker even with the "bugs" and issues I had to sort out mech. and eec related. I think the "300hp" is more or less an absolute as not every motor that brings in x,y, or z amount of air will make that number due to how the combo is setup...however it can be in the "ballpark" like instead of 300hp they see 285 or something. Bottom line when it pegs it pegs and every combo can be alittle diff. so you dont know until you log/read the maf signal.

As far as what to look for in the transfer...I would say see were you go WOT and were your not at WOT by loop status. Try to keep as many non-WOT entry points in the area of the transfer that is "all bunched together". Your probably not going to get ALL of them there but the more you do get the better the drivability as there simply are more data points. If you want to compare I made a thread in the tuning section with several stock mafs and a few aftermarket mafs transfer...feel free to compare your stock meter to others and were the logs loop state changes. I hope to eventually get the maf transfers onto the wiki but have only gotten one up there so far.

I see no reason why the maf should not be as thought out as the rest of the combo why have a maf that pegs at like 1,300hg or 1,400hg when you only need 1,000hg.

BTW-Grady the Lmaf is off a gen2 lightning that had the heaten 5.4. The gen1 had the n/a 5.8 and all were SD (so no maf).

poboys 94 · Jul 25, 2007

final5-0 said:
Go back and read this thread over again

You are still thinking like the masses

You need to unlearn all that junk

I am not pickin on ya

I am sayin ... Go over and over the info until you grasp it

You won't be much of a self tuner
if
You don't comprehend this stuff

Its that important :Word:

Again ... I spent a GOOD bit of time trying to get my head around it

Grady

Well thanks for not picking on me I know I can be stubborn when it comes to learning new things but at least Im not afraid to ask But I get it: it doesnt matter what MAF is used as long as the PCM knows (tuner) and the only reason to change injectors (larger) is if more air is being passed thru and the fuel needs are not suffient to keep up> GOD I hope thats right

poboys 94 · Jul 25, 2007

QUOTE=blksn955.o;7016322]Honestly I have not seen any logs from a Pro-M with 19's so maybe there is something with how there "foolery" works. So yeah, maybe with 19's there is not that much diff. from the stocker...I would still think they would flow at least alittle more than the stocker.

I would think that since a greater amount of air is passing thru the Pro-m as opposed to the stocker tho it was caled for 19s, wouldnt the Pcm "see" this and increase the pulse width to increase fuel, and thus more power? At least during WOT tps signals ? OR....

final5-0 · Jul 25, 2007

poboys 94 said:
Well thanks for not picking on me I know I can be stubborn when it comes to learning new things but at least Im not afraid to ask But I get it: it doesnt matter what MAF is used as long as the PCM knows (tuner) and the only reason to change injectors (larger) is if more air is being passed thru and the fuel needs are not suffient to keep up> GOD I hope thats right

There you go

Now you're starting to get with the program

Pick on you
If the truth be made known
You have my respect for hanging in here

The reason I asked you to look over things once more was when
you asked about the Lightning meter and matching inj's

I was trying to call your attention just once more to the fact that
OEM meters are not caled for a certain size inj :Word:

Now that you are starting to see the light here

How about a little thought provoking maf/inj quiz

We said OEM meters are not caled to a certain size inj
and
Here is an application that shows that to be true

Fact ... 94-95 GT's & Cobra's use the same meter
Fact ... GT's use 19's & Cobra's use 24's

Even though the Cobra pcm is programmed with a slightly
different maf transfer and inj size value to reflect 24's

How was Ford able to do ALL THAT
with the exact same meter

Hint for ya

If you can see how this is possible

It can really help to see the relationship
between aif flow requirements and fuel requirements

Grady

rj95svt · Jul 25, 2007

I have a question for ya. I know that the GT and cobra's have the same maf. How come the cobra has a different transfer function in the computer? If both mafs are the same doesn't one of the curves have to be inaccurate? The reason I ask this is because I see that people spend a lot of time dialing in there maf curves with the aftermarket meters to help cure driveabilty problems. Yet ford programed two different curves in the computers for the same maf. I haven't actually seen the curves compared but I have heard that there is some minor differences. I'm just curious how this would work.

poboys 94 · Jul 25, 2007

final5-0 said:
There you go

Now you're starting to get with the program

Pick on you
If the truth be made known
You have my respect for hanging in here

The reason I asked you to look over things once more was when
you asked about the Lightning meter and matching inj's

I was trying to call your attention just once more to the fact that
OEM meters are not caled for a certain size inj :Word:

Now that you are starting to see the light here

How about a little thought provoking maf/inj quiz

We said OEM meters are not caled to a certain size inj
and
Here is an application that shows that to be true

Fact ... 94-95 GT's & Cobra's use the same meter
Fact ... GT's use 19's & Cobra's use 24's

Even though the Cobra pcm is programmed with a slightly
different maf transfer and inj size value to reflect 24's

How was Ford able to do ALL THAT
with the exact same meter

Hint for ya

If you can see how this is possible

It can really help to see the relationship
between aif flow requirements and fuel requirements

Grady

Well...the Maf determines load--- Off the top--Im thinking the Cobra eec has different load tables for fuel and spark--so the same amount of air going thru both the Gt or the Cobra using the same meter- can work for both injectors using the different tables (measurements)

final5-0 · Jul 25, 2007

poboys 94 said:
Well...the Maf determines load--- Off the top--Im thinking the Cobra eec has different load tables for fuel and spark--so the same amount of air going thru both the Gt or the Cobra using the same meter- can work for both injectors using the different tables (measurements)

As I see it ... You kinda sorta get it

Allow me to lay it out in such a fashion that will hopefully
help you to see the bare bone basics for each combo.

Fuel first

19's are sufficient to support the GT

24's are needed for the Cobra due to greater hp production

You use those formulas you can find all over the net to
determine inj size

Notice we have not talked about a meter here and at this point in
time ... it has nothing to do with our inj size selection. We choose
their size based upon hp production.

Now ... Lets talk airflow

The GT motor will not generate as much air flow as the Cobra
however
The Cobra will not generate enough additional air flow to render
the same meter ineffective ( it won't peg it )

Does that make sense

How about we throw a 3rd Stang in the mix here

Take my humble little AFR/FTI/Edel combo

I used the very same OEM meter

I used 30's because I did not feel comfortable with 24's

I was able to use that same meter because my combo generated
air flow right to the edge of its 5.0 volt limit

Just trying to show

You pick a meter based upon the amount of air flow a
combo can generate ... not inj size choice

You pick inj's based upon a combo's power output ... not meter calibration

True ... if you don't have pcm access ...
You'll have to get involved in the after market meter
manufactures cheat method

That cheat method ... it can cause confusion
If one looks closely in how all this maf & inj stuff comes together

Grady

final5-0 · Jul 25, 2007

rj95svt said:
I have a question for ya. I know that the GT and cobra's have the same maf. How come the cobra has a different transfer function in the computer? If both mafs are the same doesn't one of the curves have to be inaccurate? The reason I ask this is because I see that people spend a lot of time dialing in there maf curves with the aftermarket meters to help cure driveabilty problems. Yet ford programed two different curves in the computers for the same maf. I haven't actually seen the curves compared but I have heard that there is some minor differences. I'm just curious how this would work.

Did I answer all or some of your Q's and concerns in that other post

If not ... ask away

I'll answer ... if I know it ... that is

Grady

blksn955.o · Jul 25, 2007

poboys 94 said:
I would think that since a greater amount of air is passing thru the Pro-m as opposed to the stocker tho it was caled for 19s, wouldnt the Pcm "see" this and increase the pulse width to increase fuel, and thus more power? At least during WOT tps signals ? OR....

I would assume that if there is more flow that the pro-m/pmas would still just offset the value slightly as that is how the pro-m stuff basicly works...it might just be a slight offset so it can still be "close" with stock 19's. Since the eec would get a false maf reading the eec would not know to increase PW, but since there is no change but more air maybe run alittle lean/rich up top making alittle more power depending on what way it goes, not to mention what the KAMFR and rest of the transfer causes the WOT part to react to the mafs readings....

That is thinking out loud about how the eec and a cheat maf works...like I said I do not recall ever really seeing too many mafs "cald" for the stock inj.

rj95svt · Jul 26, 2007

My only question is if the transfer curve is supposed to be a accurate representation of the voltage put out by the meter per a given mass of air how can the same meter have a different curve when used in different applications (Cobra and GT). If the curve is different one of the curves cannot be a entirely accurate representation of the actual airflow at the meter can it?

final5-0 · Jul 26, 2007

rj95svt said:
My only question is if the transfer curve is supposed to be a accurate representation of the voltage put out by the meter per a given mass of air how can the same meter have a different curve when used in different applications (Cobra and GT). If the curve is different one of the curves cannot be a entirely accurate representation of the actual airflow at the meter can it?

Take 10 ProM meters that were designed for the same application ...
They can all have a bit different values on their flow sheets

I do wanna point out the transfer curve is in the pcm ... not the meter

Again ... the transfer curves in our two example combos
are not ALL that different

The curve can be manipulated a bit here and there to make the
tune more optimum.

Over the years I've been involved in self tuning ......
I've seen more and more peeps find a more stable tune .....
With less and less changing of the original curve values

Sure ... a bit of fine tuning here and there ... but ... small changes
You know ... a small tweek or two on the lowest points to help
with large inj's for a more stable idle or something similar

These days more and more peeps work with ...
inj values
air flow values
and the like

as opposed to ...
hacking up various sections of the curve with large changes

My viewpoint of the above info is mostly about Closed Loop tuning

Now ... when you move over to Open Loop (wot)

You can work with the
fuel tables
t curve
or
both

I choose to do both
but
I got no prob working with the upper part of the curve
to dial in my desired final af ratio :Word:

Just for you

I'll go back and look at a few points of the upper part of the original
30 point curve I built and compare them to my latest tune so
you can see the changes.

It will be a bit later on today

Grady

rj95svt · Jul 26, 2007

That's what I was curious about. Thanks Grady

final5-0 · Jul 26, 2007

OK

I grabbed a few points on the upper end of the t curve from my original
9 to 30 point conversion efforts and my latest t curve so you can see
the changes.

This upper part of the curve represents wot conditions

I setup my af ratio not only by using maf kg/hr value curve changes
but also with ......
Same af ratio values in all cells of the highest load row of the fuel table

My wide band was then used to verify the desired fuel table af ratio
values matched as a result of my kg/hr curve point tweecs.

Here are the values ... they read from left to right
maf volt points
original curve kg/hr points
latest curve kg/hr points
% of change

3.3 ... 500 ... 561 ... +12%
3.5 ... 582 ... 637 ... +09%
3.7 ... 675 ... 726 ... +07%
3.9 ... 780 ... 832 ... +06%
4.1 ... 897 ... 913 ... +02%

Now ... remember when we were talking about how most peeps leave
the C L portion of the curve intact for a more stable tune.

Its been so long since I setup or even looked at all that stuff

Well ... my curiosity got the best of me
I took a look see at all that junk while I had the data handy

From a maf voltage range of 1.6 to 2.5 the curve was unchanged

Its in that area of the tune (CL) that changes were made with ...
inj slopes
inj offsets
inf breakpoint
minimum pulse width
air flow values
etc

btw ... maybe this will help you relate to things ...
this is a bit above idle to almost my CL/OL breakpoint

Sooooo ... that kinds shows the curve values supplied by ProM for
my shorty 80mm worked quite nicely for me

Has any of this stuff helped you to see the light

Grady

rj95svt · Jul 26, 2007

yeah I believe I've learned alot in this thread. Thanks Grady!

BTW: I think that I've found a used tweecer r/t here locally that I'm gonna try to buy.

How does a C&L Maf work on our cars?

rj95svt

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