Hey guys. Would like to thank everyone for thier comments in advance. If some of the more knowledgable people on the forum would please endulge myself and others here on this forum. Please post your opinions and thoughts on which system is better . MAP or MAF. Yeah sounds a little generalized but please play along.
I think we all know why i am asking. Just post some facts please and why you prefer to tune in that fashion. Also the strengths and weeknesses of both sensors.
Regards Nick

 

bump

 

Ultimately, it boils down to this:

A MAF is just a hot wire that measures airflow in grams/second by how much that airflow cools down the hotwire, outputting a voltage to the ECU. Whether you have a 3.0", 3.5" or 4.0" housing, you're going to hit a wall eventually and the MAF will become a restriction in your intake system.

A MAP sensor runs off of a nipple on your intake manifold and doesn't measure flow, it measures pressure (or boost). A MAP can also be used to measure load more effectively than a MAF can. If it's a 3.0 bar MAP, it can read up to 2.0 bar of manifold pressure, or 30psi.

I've never seen a MAP sensor go bad from too much boost, it just can't read over a certain pressure. MAF's, on the other hand, can only flow a certain amount of air until you rip the hotwire out of the housing. I think I recall Al mentioning that the stock MAF maxes out around 450hp, don't know if that was whp or not.

Bottom line, if you're just doing basic boltons, a MAF based setup will be fine. If you're going crazy enough to need a built block, you might want to switch over to speed density.

Disclaimer: I know nothing about this other than what I've learned from talking with guys who have built very fast turbo cars. Any additional input would be welcome.

 

“Manifold Absolute Pressure” as the name implies, monitors pressure and temperature to derive air flow.

“Mass AirFlow” measurement counts the frequency of formation of vortices created in the lee of a small obstruction placed in the inlet air flow. To produce consistent results the air flow is made uniform by being passed through the honeycomb-like material some may be familiar with. This material does present some airflow restriction.

MAF tends to give more precise results but does not easily accommodate higher volumes of air. Though less precise, perhaps MAP is acceptably accurate and typically continues to function at higher volumes.

Keep in mind that most engine control systems may also monitor engine speed and throttle position to determine air consumption.

 

Is it still true that MAF is better able to compensate for daily weather and altitude changes? MAF actually measures the amount of air entering the engine, MAP does it by inference ? Instead of counting every person that enters the gym (MAF), you try and get a count by measuring how much the floor bows =)...it's not as acurate.

 

my friend has an 11 second talon and he switched out the OE MAF for a GM 3 inch hot wire. it works awsome.

 

Ive heard alot about going to different frequency meters like this one and working really well.

 

Hmm.. interesting that I came across this post.. I found a recent useful article on the MAF sensor (Karmann Vortex)

I need to clarify a few things that I see here though.. Our MAF sensor does not use a hot wire, in fact a hot wire sensor if I recall is referred to Speed Density since the speed and density of the air is determined by how much electricity is required to maintain the temp of the hot wire.

Our cars use a MAF sensor that has a little airfoil in there that generates little vortices (swirls in the air) and (if I've read correctly) the quantity of those swirls as it passes through the detector is the Karmann frequency.

I am under the impression that our MAF sensor is similar, if not identical to the 2G DSM sensor.. If its identical, then the GM MAF sensor conversion and the translator kit would work in our cars. (If someone can give me the link of a good kit, I will buy it and try it)

I'd like to see a MAP to MAF translator.. I think someone mentioned its not as accurate, but Its one of those things.. under higher boost, it probably has its advantages.

OOOh.. another thought, if our MAF sensors are the same (or similar) to the 2G DSM MAF.. then its VERY VERY VERY important that you anchor your aftermarket air filter assembly, since the vibrations can cause the MAF sensor to read incorrectly periodically therefore under certain circumstances (Part throttle, at some speeds, under some loads) the vibrations can be transmitted to an unachored assembly and there's your drivability issue that feels like fuel cut. (or even triggers fuel cut)

http://members.rogers.com/mrjackson9/MAF/MAF_Detail.htm

This is the article that I read that allowed me to make a little more sense of things. (Our MAF's are most similar to the 2G DSM, so in theory, unless our MAF is significantly different in size, or calibration, a 2G MAF translator kit assuming its wired the same, should work on our car)

 

Really nice posts guys. Keep them comming.
Just a little question here on the accuracy of the MAP. If it is calibrated to the specific application, using compensation for airtemp and altitude , then why would it be less accurate?
I can see when mods are made to the existing setup that would throw it off but if then you adjust the output im sure you would be just as accurate.
Anyone care to comment.