The MAF sensor works by internally measuring the temperature of the air coming into the system. It then uses the wires to heat the small amount of air that is actually touching the wires, a fixed number of degrees above the incoming air. By measuring the electrical power required to heat the air, and knowing the specific heat of air, the MAF sensor can calculated the "mass" (or roughly "pounds") of air entering the engine. It then converts this signal to a variable frequency output. Inside the PCM, there is a calibration table that converts the frequency to a "mass air flow" rate.

The calibration chart is based on the specific configuration of the stock MAF sensor and air inlet ducting. If you change any component of the system, you upset the calibration of the sensor. The "screen" - actually a honeycomb, made out of thin paper - is there to provide a uniform flow of air across the full face area of the sensor. In this way, since the amount of air flowing past the sensors is the same as the amount of air flowing in other parts of the sensor, it can calculate the total air mass flow through the sensor by measuring only the small sample of air that touches the wire. Removing the "screen", or removing the dividing wing in the housing inlet and outlet halves destroys the calibration of the sensor.


by : F.W. FORSYTHE

SO QUIT TAKING THE SCREEN OUT OF YOUR MAF !!!

 

Wish I had said that

 

Sure you jest: you've only been saying it for umpteen years.

 

Well, you probably never wasted our bandwidth by making a new thread about it, so it doesn't count.

Plus you don't use enough cute little asterisks in your titles...

 

i know right ... you girl thinks they are cute too

 

Lots of cars run just fine with it and without it. It's a personal choice, but it has clearly been an issue for some people who have removed it. If it ain't broke, don't fix (remove) it.

 

That being said there are still people that swear the screen is a restriction.

 

I gained 3rwhp by descreening my maf on the dyno. And my tuner recomends descreening the MAF's. It's porting them that causes a problem not descreaning them.

 

A 3 RWHP gain on a dyno doesn't mean much. It's what gains you maintain after the dyno that count. Just sayin'. BTW, the screen also serves to keep debris from entering the intake. It is possible that something might give way in between the filter and the MAF, e.g, your CAI drops the filter and and some crap is scooped up----the last barrier is the screen. The engine is only going to use so much air unless it is pushed in with a SC/TC. Messing with the sensors in the MAF are more likely to compromise the integrity of the PCM to make the desired adjustments. Or not.....

Other than that, I only responded because I'm bored.

 

Colorado MAF FTMFW... I hate that three thermistor setup crap.

http://cgi.ebay.com/ebaymotors/2004-...QQcmdZViewItem

 

Madz28 tunes cars for a descreen

 

The screen in the MAF is made out of paper?

 

It is thin and flemsy, if it is paper is coated with something.

 

I'm going to respectfully disagree with Ingineer on this one. I still use the stock calibration on my descreened MAF. Descreening does not affect the calibration. I've disabled my blms and my car runs at 14.7 on the dynojet wideband AFR guage all the time except when decelling.

 

14.7? stoich....with a f1a...wtf