MAF versus MAP

[dyn085]

I wanted to answer the question: Why is there a mass airflow parameter that can be datalogged if the MAF sensor is not being used?

The speed density on these cars is much more than a MAPxRPM VE table. It uses a quadratic equation based on many parameters to use RPM to find a parameter that is basically airflowmass/pressure.This is done for every combination of camshaft angles as well. But this is measured not in airflow/time, but actually airflow/event (basically standardized per RPM, not time) and then basically is multiplied by rpm/2. (There is one intake stroke for every 2 Revs). This is how the ECU can give you airflow mass without a MAF sensor. The ecu needs to know airflow mass to know how much fuel to inject. You can also work backwards from fuel injected amount and AFR to find airflow.

TLDR: Speed density still measures airflow.

Also, if you unplug the MAF you get a AIT sensor CEL, not a maf sensor CEL.

And this is why your LTFT/STFT doesn't get out of shape that much through 'stage 3' modifications - it simply doesn't affect volumetric efficiency to the degree that you would need to use the quadratic formula to change it. Instead of measuring (MAF) the air and then adding fuel, we're calculating (MAP) air and adding fuel and then just allowing the fuel trims to make up the difference. The quadratic formula is part of the tooling used for tuning, its just not necessary until you make substantial changes to airflow, like adding a turbo.

Then you get to learn about HDFX and cam-angle pairs along with locking them out and doing WOT pulls, which is ridiculously time consuming.


Tl;dr- As is stated in the tuning guide and logging parameters, air is 'calculated' and not 'measured'.
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[antarctica24]

I wanted to answer the question: Why is there a mass airflow parameter that can be datalogged if the MAF sensor is not being used?

The speed density on these cars is much more than a MAPxRPM VE table. It uses a quadratic equation based on many parameters to use RPM to find a parameter that is basically airflowmass/pressure.This is done for every combination of camshaft angles as well. But this is measured not in airflow/time, but actually airflow/event (basically standardized per RPM, not time) and then basically is multiplied by rpm/2. (There is one intake stroke for every 2 Revs). This is how the ECU can give you airflow mass without a MAF sensor. The ecu needs to know airflow mass to know how much fuel to inject. You can also work backwards from fuel injected amount and AFR to find airflow.

TLDR: Speed density still measures airflow.

Also, if you unplug the MAF you get a AIT sensor CEL, not a maf sensor CEL.

Mitch THANK YOU. A well thought well expressed intelligent answer instead of "it's just a fact".

This is how it should be. Thank you again.

 

[M-Sport fan]

In short, boost control. The ECU asks for a desired pressure before the throttle body. If it sees more than it wants, it closes the throttle body to make sure that the boost doesn't get into the intake manifold.

OK, THANKS! (I thought it was something like that, or to figure pressure differential between pre, and post {the manifold mounted 'main' MAP sensor} throttle plate.)

 

[dyn085]

Mitch THANK YOU. A well thought well expressed intelligent answer instead of "it's just a fact".

This is how it should be. Thank you again.

Why would you need a MAP system explained to you when you've repeatedly chained to know how they work? You even used that as your basis as to why you thought MAF was superior. I probably would have been willing to explain it to you had you not professed to already know how it works.

Regardless of whether you actually knew or not, I've given you plenty of links and information to learn from, both in this thread and a year ago on the other threads.

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[LilPartyBox]

See what had happened waasss, the MAF sensor fell off of the traction bar causing the wheel hop to run rich.

 

[Jason@dizzytuning]

Mitch;

What is the purpose/function of the (MAP?) sensor down on the factory cold side charge pipe (also switched over to your and others' aftermarket pipes)?

The cold pipe sensor is for TIP calculations, or throttle inlet pressure. This is the main function of boost target calculations and corrections. The ECU targets a value called "TIP Desired", and references the actual current value "TIP Actual". These 2 values help keep boost in check and close the throttle if boost is getting too high.

The manifold sensor is also a barometric pressure sensor. So this takes into account the local barometric presssure, as well as temperature (for fuel calculations) other pressures inside the manifold. This is the most important sensor to a SD (speed density) system.

 

[dyn085]

See what had happened waasss, the MAF sensor fell off of the traction bar causing the wheel hop to run rich.

Lol, and it's all you're fault for not explaining it at the lowest level because I professed to know everything about it already.

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[antarctica24]

Why would you need a MAP system explained to you when you've repeatedly chained to know how they work? You even used that as your basis as to why you thought MAF was superior. I probably would have been willing to explain it to you had you not professed to already know how it works.

Regardless of whether you actually knew or not, I've given you plenty of links and information to learn from, both in this thread and a year ago on the other threads.

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You know what you need to drop it. I've heard a lot about you trolling on other forums with your attitude. Nobody here is interested if you can't be nice. I asked you for proof, you never gave any. The only proof that was provided was the proof I got from my tuner. Your word and insults as to why something works or does not work is not proof. Had you given an explanation as Mitch did then perhaps I might have bought in but instead you were an ass and again offered no proof other than your word which is not proof.

 

[M-Sport fan]

The cold pipe sensor is for TIP calculations, or throttle inlet pressure. This is the main function of boost target calculations and corrections. The ECU targets a value called "TIP Desired", and references the actual current value "TIP Actual". These 2 values help keep boost in check and close the throttle if boost is getting too high.

The manifold sensor is also a barometric pressure sensor. So this takes into account the local barometric presssure, as well as temperature (for fuel calculations) other pressures inside the manifold. This is the most important sensor to a SD (speed density) system.

Thank you for the even further detailed explanation!

 

[dyn085]

You know what you need to drop it. I've heard a lot about you trolling on other forums with your attitude. Nobody here is interested if you can't be nice. I asked you for proof, you never gave any. The only proof that was provided was the proof I got from my tuner. Your word and insults as to why something works or does not work is not proof. Had you given an explanation as Mitch did then perhaps I might have bought in but instead you were an ass and again offered no proof other than your word which is not proof.

Come on man, take some responsibility. I told you and linked you multiple times over the last year of places that could confirm exactly what I told you. There were times I was nice, times I wasn't, and everywhere in-between. I've linked you to professionals that were tuning the ST before it was being sold, shown you my own personal datalogs, and explained how you could test it yourself. Other high-rep members have even gotten on here and backed my statements. I've gone far and above what any reasonable member could or should have done and all you've done is put your head in the sand.

Want more proof of how you've been acting here? Your 'proof that was provided' is literally only an email response from Randy. The same Randy that you repeatedly swore, even in this thread, was giving you all of the proof that this was a MAF-based tune. Surely that irony isn't lost on you, is it?

I tried letting this end in a relatively dignified fashion when I told you to bury the hatchet and all you want to do is whine in your following responses. You can't try to disqualify your offensive statements and then cry that I'm the one that needs to drop it after you keep pouting. Be a man about this and stop posting because it's done and over with.

Maybe we'll get lucky and this thread will be locked too so that the scars can fade into the past. After all, we now all know that its not a MAF-based tune so there's not really much more to expound upon.

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[me32]

Well this thread sure went down hill fast lol.

 

[Truth in Ruin]

Well this thread sure went down hill fast lol.

Yep!

Happy Anniversary to the Pierce Motorsport 2-point brace review... http://www.fiestastforum.com/forum/...t-lower-chassis-brace-rear-torsion-bar-A-mods

 

[me32]

Yep!

Happy Anniversary to the Pierce Motorsport 2-point brace review... http://www.fiestastforum.com/forum/...t-lower-chassis-brace-rear-torsion-bar-A-mods

Thanks for sharing I got a good kick out of that thread. Seems things do rise from the dead

 

[jeff]

Thanks for sharing I got a good kick out of that thread. Seems things do rise from the dead

It was a good thread until it was ruined and shut down. Those bars are still doing well one year later. I highly recommend them to anyone seeking to improve the things I mentioned there.

 

[me32]

It was a good thread until it was ruined and shut down. Those bars are still doing well one year later. I highly recommend them to anyone seeking to improve the things I mentioned there.

There was alot of good info in that thread. I'm sure the bars do work well. There was alot of good proven data in that thread on other points too.

 

[Truth in Ruin]

It was a good thread until it was ruined and shut down. Those bars are still doing well one year later. I highly recommend them to anyone seeking to improve the things I mentioned there.

There was alot of good info in that thread. I'm sure the bars do work well. There was alot of good proven data in that thread on other points too.

Agreed. It was a great thread. Instead of being shut down- it should've been cleaned up, and kept open.

 

[Truth in Ruin]

 

[DEss]

You know what you need to drop it. I've heard a lot about you trolling on other forums with your attitude. Nobody here is interested if you can't be nice. I asked you for proof, you never gave any. The only proof that was provided was the proof I got from my tuner. Your word and insults as to why something works or does not work is not proof. Had you given an explanation as Mitch did then perhaps I might have bought in but instead you were an ass and again offered no proof other than your word which is not proof.

You seemed to have started this thread with an instruction sheet on Mountune letterhead as proof that you were right all along. Then you post your tuner's E-mail as proof that perhaps you were mistaken. If I remember correctly from the other thread, dyn085, or some other member, provided you links to Cobb literature as proof that you were wrong.

I'm curious as to why you consider the Mountune tuner's E-mail as proof but not Cobb's literature. This isn't a dig by any means, just curious as to why the bias towards your tuner's word? And, is his word really 'proof?'

 

[me32]

Agreed. It was a great thread. Instead of being shut down- it should've been cleaned up, and kept open.

That would be to easy

 

[dyn085]

Yep!

Happy Anniversary to the Pierce Motorsport 2-point brace review... http://www.fiestastforum.com/forum/...t-lower-chassis-brace-rear-torsion-bar-A-mods

I think it's neat that the same thread has been linked twice now by different people, lol. Definitely a good thread with good info.

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