does anyone know how to change the flapper style maf to a 1.8L miata hot wire style maf. has anyone hooked up a map sensor in place of a maf?

 

I cant think of the name but I know a few companies make hot wire conversion kits.

They are not cheap. I looked into one for my ford probe GT and it was like $500

But if your looking for big NA power thats the way to go.

 

i have one off a 1st gen (1.8 L) miata, but it has a 5 prong plug and the rex has a seven prong plug. does anyone know what the extraprongs are for? does anyone have wiring diagrams for it?

 

If your looking at $500 spend another $100 or so, and get a stand alone microtech system. The computer uses a map sensor insted of the maf. And you get more tuneablity anyways. But that would only be if you can't find a cheep way of doing it.

 

i'd like to use the maf sensor if i can...i need to know what those prongs are for...*scratches head* lol

 

I doubt they'd be a direct swap even if they had the same number of pins (or you only used 5 of the seven). Thats like thinking that by changing the shape of a plug you can go from the US recepticles to european ones.

 

im going to end up re-wiring it, i just dont know how...i need help.

 

Dude, its like saying your going to hook up a fire-wire card to an optical cable by rewiring it. Even if it were possible, it wouldn't work very well.

I don't know a ton about the actual MAF electrical implementations, but the fundemental means by which flap-types and hot wire MAFs work is so different, I can't even imagine that the electrical properties would be similar enough that you could hook up the bare bone electronics, to the different ECU's without problems, nevermind the differences in output due to air flow. I bet most of the $500 that aftermarket hot wire conversion kits cost goes to a third party "black-box" that lets the ECU and MAF comunicate properly.

 

it can be done, theres a kit to do it for miatas, ill let you know how it turns out.

 

Fatboy7

Speaking of the black box... you obviously understand that it can be done. There are standards that are set and this is the case in any business. What that means is that you build products with room for later improvement. You build it in layers, and these layers have certain outputs. as long as the output values are understood the underlying implementation can be changed. In allowing change we allow better algorithms or ideas to take the place of older outdated ideas/implementations.

 

I'm sure it can be done, but is well beyond the scope of a simple rewiring. To tackle this kind of project to first have to know what the inputs and outputs are, for both models. Standards exist, but are also very flexible. Auto car makers will often completely ditch the standard everytime a particular car goes through a redesign. Because they know that the car will share but a few parts with the out-dated predecessor, rarely do they make it conform the the standard previously set.

Hotwire sensors are considered by some to be the best MAF available, because it actually measures the mass of air as it goes by. Most other MAFS have to be temperature, and pressure compensated. The controls of the hotwire maf is still a bit of a mystery to me. Whether or not you can get the two to communicate without serious research effort is really hard to say.

I'm sure there is a reason that the hotwire MAF conversion on the Ford Probe / Mazda MX-6, costs $500.

 

HKS makes a vein pressure converter (VPC) that does this exact thing. It is well over $800 though so the Microtech would be a better choice. If you go to a bookstore, check out a book on Bosch fuel injection. It explains the different types used on different cars and some way to tweak them. Not all Bosch systems use afm's. On the type of system that your car has there are no mods that can be done to it, at least not easily. You will not be able to use a maf instead of an afm. A maf works by heating a wire that runs across the airstream. At different temperatures it sends a different voltage signal out to the computer. As more air flows past the maf it gets cooler which changes the value. On an afm there is a flapper door that is pulled open based on engine suction. The location of the door determines the value that the computer sees. One of your extra wires is a fuel cutoff switch in the event that the engine dies. Just give it up. You aren't going to get it to work for any price that would even make it remotely worth it. These systems have been around for 30 years. If it were a simple thing to do a swap like this you would see everyone doing it. Many of the Miata guys are swapping to 2nd gen afms since they are electrically compatible but are larger.