tigerboy rei i

I know it can be done, just wanted some help figuring out how to complete it. I know of one other person attempting this with a Mustang 5.0 MAF, although I haven't heard anything from it since.

HAILERS

'cause it can't be done

Evil Aviator

Despite performing the same function, a flapper-type air flow meter and a hot wire mass air flow meter operate on different electronic principles. It is similar to how a narrowband O2 sensor and wideband O2 sensor are not compatible even though they serve the same function. Therefore, you can't convert to a MAF unless you install a computer that can control the MAF sensor element.

tigerboy rei i

What about This Page? Is it feasable in any way?

I mean, sounds like a lot of research and computer stuff, but I'm a nerd and have too much time on my hands. I guess if I want to try to replicate this I'd just have log the voltage and resistances, and write a formula to fit, then program it for the chip. I've access to a newish digital scope hooked up to a computer, so logging might be easy, and plotting all the necessary graphs and calculating the formula will be easy. It's just the programming of some sort of micro controller that'll be rough.

SirCygnus

iTrader: (1)

just run a stand alone ECu and youll be worlds ahead.

or just remove it with the MAP ecu.

katkaroto

this kinda sounds like what the next rtek ecu is going to be like...

Aaron Cake

iTrader: (1)

Anything can be done with enough time and money wasted. The reason it is not done is because it is of dubious benefit.

If you really want a DIY project that will allow you unlimited choices in engine peripherals and complete tunability, get a Megasquirt.

prof

I believe someone on the forum was selling a device to do just that.

From what I've researched - both MAF and AFM provide a non linear signal - but the MAF has a rising voltage with airflow (rising most at the start of the graph) and the AFM has a falling voltage (when referenced at the ECU measuring pin - and again falling most at the start of the graph). The subtle problems are the fact that the MAF values will change with air temp, since that's how the hot wire sensor works. If you could 'normalize' the curve with temperature and use an IAT sensor then it should be possible for a microcontroller (such as PIC or AVR) to take the input from a MAF and mimick the expected input to the ECU.

From my observations with the Emanage logging the AFM signal on a series 5 (that's the cone shaped AFM), the reading hits 0 volts at around 12 psi, but the stock ECU is using the MAP sensor by then to control fuelling, it seems the AFM has more use in the vacuum and lower boost parts of the map - where it gives the largest change in voltage against airflow. I suspect you'd be able to get a better tune in the lower parts of the map with an AFM, rather than doing speed density with just a MAP sensor - but that's just my thoughts.

If you're making a daily driver then I'd keep the AFM or look to do a conversion, if you're making a race / drag car just ditch it and use a standalone or piggyback to get rid of it.

Evil Aviator

Dubious benefit? So you see no benefit in being able to brag that you spent countless hours and $50 in junk yard and Radio Shack parts in order run your engine off of the SAME non-tunable, nasty, POS, 8-bit, 1984-vintage stock computer? You could even 'upgrade' by spending $400 on an Rtek and run the engine off of the SAME tunable, nasty, POS, 8-bit, 1984-vintage stock computer! Just think, as they blow past you in their faster cars, you could laugh at all of the suckers who spent $1,000 on a real EMS.

Shhhh, don't tell the noobs that the Megasquirt II can work with a MAF sensor.

arghx

iTrader: (3)

MAF sensors effectively have an integrated IAT function in them. They don't need a separate IAT like the older flapper-style meters. The factory ECU will still apply separate IAT correction however unless you remove the IAT and install a resistor in its place. The final result is still just not very useful. Scaling MAF sensors is a bitch when you start modding a car. The MAF sensor used on the STi's and Rx-8 can be a huge pain to deal with once you start doing custom intakes. They have to be carefully calibrated and carefully positioned in the intakes stream or they make the car run like ****.

Search Bosch L-Jetronic online. It is the forefather of modern MAF-based systems, and is essentially the engine management system that 80s japanese cars run (there are several variants). Also search Bosch D-Jetronic. That is the forefather of speed-density systems most common on standalones, one of earliest of which was in the Porsche 914.

Aaron Cake

iTrader: (1)

It's teal, the colour of sarcasm.

I believe the MSI supports an AFM as well, though the feature has been listed as "beta" for several years.

Just to nitpick, but the flapper style AFM also has a temperature sensor.

And is the system used in the 1st and 2nd gen RX-7.

D-Jetronic is the bastard child of EFI systems designed by Lucifer himself. No human in their right mind would ever design an inductive MAP sensor...ever. Therefore it was designed by the Devil.