Seeing that the MAF is just calculating the airflow though the MAF, could you in theory Calibrate the MAF in park by just going through the RPM/Freq ranges?
Seeing that the MAF is just calculating the airflow though the MAF, could you in theory Calibrate the MAF in park by just going through the RPM/Freq ranges?
No it has to be under a load…
Email Tunes, [email protected]
96 TA Blown/Stroked, 4L80E/Fab 9
15 C7 A8 H/C 2.3 Blower/PI
14 Gen 5 Viper
Custom Mid Engine chassis, AKA GalBen C
IF it worked that way, it would make all our lives easier.
If the intake tract and MAF sensor is stock, it will not require much in the way of MAF calibration adjustment anyway. That is why I set my stuff to run MAF only, adjust the MAF curve and datalog the VE table.Originally Posted by Mingus
Last edited by Fast4.7; 03-25-2023 at 10:47 PM.
If you free rev the engine and calibrate the MAF frequency table say.... at 5000Hz, is it going to change the amount of airmass at 5000Hz when you are driving under a load?
Yes
It will not provided your injector data is correct. Airflow is airflow.
Fast, that is what I was saying. How the air got to the sensor does not matter. Loaded, unloaded, parked or on the parkway.
gtstorey
Interesting. So why do we not have a 3d table like the VE/SD if it is load based? What is the load axis at any given frequency?
How does the mass airflow sensor measure airflow you might ask?
When the temperature difference between the two sensing wires changes, the MAF sensor automatically increases or decreases the current to the heated wire to compensate. The current is then changed to a frequency or a voltage that is sent to the ECU and interpreted as air flow.
Is the frequency / voltage derived from the Current Delta using calculation of airmass passing the sensor?
Can the same Mass of air (g/s) be referenced by more than 1 frequency of the same sensor? Think about this,.... if free rev motor... at 5000Hz is calculated as 38 g/s. Where else is the 38 g/s going to show up in the frequency table Hmm? 2200Hz, 3500Hz oh maybe higher 6300Hz?
If MAF is load dependent, free revving is very little load, yes? and we get 38g/s at 5000Hz (example).
Are we suggesting that when a load or stress the motor... say on a load holding Dyno, 2000RPM, the calibrated Mass of air at 5000Hz free revving is going to be a different density because now the engine loaded? ,.... where would that 38 g/s air MASS show up NOW that there is a load? at what frequency would we need to reposition 38g/s air MASS reference in the table?
I can appreciate the fact that as engine load changes, the amount of air Mass required for said load to reach the target AFR is going to change, but that air MASS is NOT going to have the SAME frequency because it is not the same MASS.
Peace to all,
Hondaeater.
If there were a way to hold the engine speed steady long enough to collect the data... remember it can't be at part throttle. Has to be WOT. WOT in neutral, MAF Hz goes up real damn quick. Any data collected would be at best one cell hit, and probably not all that accurate if it grabbed anything at all.
To some extent it will work, however you will be moving more air at 5000 rpm when under load than just revving in park/neutral, so you won't get all of the way through the maf table.
My LNF does have additional corrections for the MAF based upon load.
If this conversation is about calibrating a MAF during free revs, I will flip a table.
Of course it is. Wouldn't that be easier/quicker?
Also, wouldn't it be cool if we had anti-gravity? Yes. Yes it would be cool. Think of all the amazing things we could do. The TikToks would be insane.
I knew I was on the entertainment channel
I mean, have you checked out my signature..? Its basically the wild west around here.
You had mentioned it has to be at WOT to collect MAF data. Please explain. I've always collected MAF data as I drove around. Is this not correct?
I really respect your opinion on this forum. You and a few others come across as knowing what your talking about. This seems to be a rare commodity now days.
So give it a try. It's just collecting data and editing the tune, it's not like you have to open the PCM and solder things, tune changes are reversible if it doesn't work.
So, what's the highest Hz you can reach in neutral without the engine experiencing rapid unscheduled disassembly?
Its possible to adjust a small range in park with the throttle closed/managing airflow, if you're using fuel feedback. There's no issue bringing it to 6krpm in park too if you felt like it and using that. The extra engine friction at speed would use up some more air. But the party is over after a few thousand hertz...like they mentioned, the load isn't there to draw on the MAF more. And any data collected from the MAF during a WOT punch is about as useful as kingtalon's text walls, so you'll want to discard the transients.
off topic: Pressure differentials, right?
Things flow from areas of high pressure towards areas of lower pressure. Happens whether you're talking liquids or gases or even solids, given a long enough timeline. This is a known fact.
Another known fact: Atmospheric pressure at sea level here on planet earth is 14.7 PSI.
Another another known fact: Pressure in outer space is 0 PSI.
The solution to all our energy problems is a simple tube (I call it the Space Straw - patent & trademark pending). One end of the Space Straw near the ground, the other end out in space: pressure differential = flow! Place a turbine in the Space Straw at ground level and generate infinite energy for free. The atmosphere that exits the top of the Space Straw falls harmlessly back to earth under gravity, thus making it infinitely renewable.
I have grant applications pending with the NSF, still waiting to hear back from them. Dunno what the hell is taking them so long. This should be a slam dunk.
im all for it!!
Would you fill us in on exactly how the OEMs calibrate the MAF sensor?
Reply With Quote
