3 wire to 5 wire MAF conversion?

[PonyKiller87]

My truck has a 3 wire MAF sensor, there seems to be more performance MAF's out there in the 5 wire type. I found a 3 to 5 wire conversion plug. Is it that simple to just switch from 3 to 5 or do I need to do other stuff to make it all work?

[lilws6]

Its that simple my slp MAF came with one the corvette MAF have 5 plug and thats why all the aftermarket ones are 5 plug. the converter works just fine on my car no problems

[Poncho]

5-wire just has the IAT integrated into it, unless I'm thinkin' of something else, which I could be, it's a bit late.

[Breecher_7]

5-wire just has the IAT integrated into it, unless I'm thinkin' of something else, which I could be, it's a bit late.

Im pretty sure your right Dan. The 3 and 5 wire mafs operate no differently. The 5 wires simply have the IAT integrated into the maf housing. :thumbsup

[BAD LS1]

Id strongly advise against this change unless you really have a plan for dialing the maf scale back in... The stock 75mm cast housing maf's descreened and ported can pass enough air to support 600 hp, the electronics inside it... now thats a diff story. they may claim its "calibrated" for that vehicle, which is just a resistor to lie to the ECM.

[PonyKiller87]

Well I was looking at a bigger throttle body, then I realized it probably doesn't do much good if the MAF is still smaller than the TB opening. Was looking around on ebay and theres a guy that sells factory 85mm MAF sensors, and I found a 85mm TB. Price is right and from what I've read just the TB makes a big difference on the 454 because stock its using the same TB as the 4.3, 5.0 and 5.7 just doesnt have the baffle on the blade.

[lilws6]

I dunno if mines calibrated i just needed to replace mine to fix the check engine light and i wasn't going to dish out the money for one from the dealer

[PonyKiller87]

Theres a guy on ebay selling a ton of the 85mm sensors, there brand new delco parts for $29

[BAD LS1]

Im not trying to be the guy that steer's you away from doing mods you want to do, but just trying to inform you of what the ripple effect will be by changing those parts. FYI, those factory MAF's are calibrated for everything to do with the orginating vehicle they came off of, so its certain the table needs to be scaled or expect very + trims and blah performance that was probably better when it was stock.

The SLP maf's have a resistor in them to cut some of the frequency signal so that its closer in line with the output of stock to keep the PCM happy. However most of them i seen with that 85mm SLP maf for sure needed up to 10% corrective acction needed to make the driveabilty come back so it was actually fun to drive and the MPG rised slightly.

Sorry if i sound like a nazi on this subject, im just spewing out my experience to try to give other a heads up.

[PonyKiller87]

This is why I ask questions before I go and buy stuff, lol.

This is something that could be taken care of with a tune when I get HP tuners right? If so I might just pick one up and throw it on the shelf for now.

[BAD LS1]

This is why I ask questions before I go and buy stuff, lol.

This is something that could be taken care of with a tune when I get HP tuners right? If so I might just pick one up and throw it on the shelf for now.

You are correct, it can be fixed through HPT. I was kinda exploiting this also to shed light on this for those who have done this mod or thought about it and have not had any correcting measures taken in the tune to take it into account. Basically it would cost HP instead of gain.

[95 TA - The Beast]

Here is a REALLY big datapoint, and it is true from 94+ on GMs with a MAF and even more so from 98+, and that is that the MAF is the only TRUE lab-grade device on any late model vehicle.

In being a lab-grade device, each and every MAF has a given calibration that is equal to the actual flow through it, thus to go with a different MAF you need a different MAF calibration in the PCM to go with it. That is why when people 'port' a MAF they are essentially destroying it, since unless you have a flow-bench and can flow a stock one and repeat it's calibration you are in no-way going to be able to 'guess' at a ported MAFs calibration and get it right...

Which brings up another point in regards to tuning, in that people that tune a car via the MAF tables are HACKING THE HELL OUT OF THE CALIBRATION!

No two ways about it, the MAF tables hold a calibration for the MAF that is equal to the flow through it, and ALL tuning adjustments need to be done in OTHER areas of the PCM. People that hack MAF tables think they are taking a 'quick way out' in tuning, but in essence are only creating other problems. The biggest issue in tuning is a complete LACK of understanding exactly how the PCM programming works. Regardless of the 'results' you may think you get, the RIGHT way is to leave the MAF tables with the right factory values for the MAF device you are using.

The entire rest of the tune relies upon the MAF giving accurate info, once you mess with the interpretation of that info you mess with everything else in a cascading manner.

Sad part is there are actually books out there that only teach people how to tune via messing with the MAF tables... Sad, sad, sad... Viewed by those with a clue as more of a way to delude the masses while allowing the 'real tuners' to rack in the cash...

[PonyKiller87]

Regardless of the 'results' you may think you get, the RIGHT way is to leave the MAF tables with the right factory values for the MAF device you are using.

Ok let me just see if I got this right based on what you said. If I buy a MAF that is stock on a 01-06 vortec 8100 engine. And I stick it on my vortec 7400 engine I should get the MAF table from the 8100 and put it in place of the stock 7400 table? Then tune the rest of the ecm?

I just want to make sure I have this all figured out before I start doing stuff and mess something up.

[95 TA - The Beast]

Ok let me just see if I got this right based on what you said. If I buy a MAF that is stock on a 01-06 vortec 8100 engine. And I stick it on my vortec 7400 engine I should get the MAF table from the 8100 and put it in place of the stock 7400 table? Then tune the rest of the ecm?

I just want to make sure I have this all figured out before I start doing stuff and mess something up.

Yes, with some caveats, in that you have to have the tables and make sure you map them properly between the originating and the new PCM. But beyond that, that is all there is to it...

Now, there will be an argument that certain cars had certain MAF table changes based upon intakes on the various cars, but that ONLY applies if you use the ENTIRE stock intake. Using a col-air intake negates this as there is really no restriction prior to the MAF...

Now, on 96/97 SS & WS6 F-Bodies they had a slightly different table than the 94-95 cars, but that was due to PCM differences as much as it was due to the fact that the factory air intake setup on the 96/97 SS & WS6s was a cold-air setup and thus they tweaked the table to take out of it the 'harmonics' of the stock air system MAF calibration on the 94-95s...

From 98+ they pretty much went to a 'clear calibration' model. Any slight differences based upon the various intake systems used were trivial enough to not worry about it, as in if you used a cold-air on those vehicles themselves it is within a range of adaption of the PCM... Not 100% ideal, but within the 1-3% or so that is not really any sort of concern...

[WhatsADSM]

Here is a REALLY big datapoint, and it is true from 94+ on GMs with a MAF and even more so from 98+, and that is that the MAF is the only TRUE lab-grade device on any late model vehicle.

In being a lab-grade device, each and every MAF has a given calibration that is equal to the actual flow through it, thus to go with a different MAF you need a different MAF calibration in the PCM to go with it. That is why when people 'port' a MAF they are essentially destroying it, since unless you have a flow-bench and can flow a stock one and repeat it's calibration you are in no-way going to be able to 'guess' at a ported MAFs calibration and get it right...

Which brings up another point in regards to tuning, in that people that tune a car via the MAF tables are HACKING THE HELL OUT OF THE CALIBRATION!

No two ways about it, the MAF tables hold a calibration for the MAF that is equal to the flow through it, and ALL tuning adjustments need to be done in OTHER areas of the PCM. People that hack MAF tables think they are taking a 'quick way out' in tuning, but in essence are only creating other problems. The biggest issue in tuning is a complete LACK of understanding exactly how the PCM programming works. Regardless of the 'results' you may think you get, the RIGHT way is to leave the MAF tables with the right factory values for the MAF device you are using.

The entire rest of the tune relies upon the MAF giving accurate info, once you mess with the interpretation of that info you mess with everything else in a cascading manner.

Sad part is there are actually books out there that only teach people how to tune via messing with the MAF tables... Sad, sad, sad... Viewed by those with a clue as more of a way to delude the masses while allowing the 'real tuners' to rack in the cash...

x2 :thumbsup

Yea, funny in the import world I see that all the time. Earlier Nissan MAFs were actually essentially sensors that bolted into a pipe. And people would actually just take a new diameter pipe and just bolt in the MAF sensor and say "Yay more range". :chair:

At one point in my cheap college kid days I did actually characterize a MAF without a flow bench. It was an earlier 3" GM MAF (Hitachi was the actual manufacturer IIRC), by placing the GM MAF essentially in series with the stock MAF. Drove around and collected a bunch of data points of stock MAF versus GM MAF points. Threw everything into excel and got out a function. Worked great actually.

[95 TA - The Beast]

At one point in my cheap college kid days I did actually characterize a MAF without a flow bench. It was an earlier 3" GM MAF (Hitachi was the actual manufacturer IIRC), by placing the GM MAF essentially in series with the stock MAF. Drove around and collected a bunch of data points of stock MAF versus GM MAF points. Threw everything into excel and got out a function. Worked great actually.

Actually you made a 'poor-mans' flow-bench... Good deal...

The only issue that won't be captured is if you reach a point where the piping before the sensor creates a turbulance, at which point you can't really use that methodology because the resultant data would be an extrapolation of the figureprint of the turbulance created by the air intake prior to the MAF...

But you are correct, the derived function should be the result of the difference in flow between the two, as long as there was enough data to determine the resulting slope of the flow difference as it will change with airflow. Only real issue with that is at which point the size of the opening becomes a restriction in itself. Again only a flow-bench would accurately capture that.

[lilws6]

You are correct, it can be fixed through HPT. I was kinda exploiting this also to shed light on this for those who have done this mod or thought about it and have not had any correcting measures taken in the tune to take it into account. Basically it would cost HP instead of gain.

So basically your saying A. My MAF is out of tune costing me HP B. i still didn't tune my car form the header install costing me HP and C. I can still run a 12.9 on street tires with all this f'd up shit? tom can you fix it for me??? i wana go faster lol that is if the diff doesn't blow up first