Euro951

What stops you from building your own MAF with a Ford MAF sensor? Or any 0-5v Maf sensor? Isn't the Autothority kit just a Stage 2 chipset with a MAF sensor and a resistor for the temp sensor? If someone already has a Autothority stage 2 chipset couldn't you just wire a MAF sensor in with basic fabrication and welding skills?

pormgb

I use a Ford 80mm Mustang Cobra MAF with a Lindsey Mafterburner on my Turbo Charged N/A, I get 14.5 AFR idling and cruising, 12.5 under boost. You could use a Ford or Bosch HFM type MAF but the air flow to voltage mapping would have to match the chips, I believe there is a thread related to using HFMs on 944s.

alxdgr8

You have to know the transfer function for the specific MAF and then need a way to tune it.

Burma Shave

Same thing that stops you from reinventing the wheel.

V2Rocket

im going to experiment with this whenever i get my hands on a late 944 DME

i have a ford contour maf with all the wires hooked up to match the stock afm plug, drawing power off the ignition coil. not going to do any software changes or anything, just plug it in and see how it feels. it wont be perfect but i suspect it will work.

Burma Shave

Since my earlier post was on the rude side, I guess I should elaborate. Some time ago, I gathered all the parts to do this after talking to John @ vitesse and another vendor. I wasn't happy with the answers John gave me regarding software for my cobbled up system but looking back he was right. If you want a sorted system, you need proper software. By the time you fab the intake parts, buy a decent filter and get chips burned and buy a mafterburner or whatever you won't save any money. In addition you will still have to sort and tune the thing. A couple hundred bucks in ebay parts will not net the same result you get from a reputable vendor.

67King

The swing door air meter thing......forget what Porsche calls if, Ford calls it a VAM (Vane Air Meter)......measures the volume of air. The PCM (Powertrain Control Module - the SAE term) of the system using that then measures barometric pressure and air charge temperature, uses all three to generate a calculated mass air flow.

The MAF directly measures the mass air flow. If you plug a MAF into a system designed to use a VAM, the PCM will then take the 0-5V signal, apply the VAM's transfer function, determine from the other inputs (baro and ACT), then feed another number into the strategy, where it is read as a mass air flow reading, and used to determine spark advance and fuel.

The CORRECT way to do this is to do it by changing the strategy in the computer. Note that strategy = code, and calibration = tuning. That means you have to change the programming in hex. I've done this on a Ford 2.3 turbo, and plugged a PROM into the back of it to provide the strategy and calibration. But the source for those PCM's is available. I don't know that it is on Porsches. If so, THAT is what you need to do. I'd been mulling over machining up a CID to put on the distributor, and run my Ford MAF on my car, but I'm thinking it'll be a lot easier to just go with the Megasquirt.

And by the way.......if you didn't follow everything I said to a T, you've got a lot of learnin' to do to be able to do this. I know how all of this works, and I still had a lot of help from a much more computer savvy friend.

Rogue_Ant

I explained some of the basic problems with a MAS conversion here:

Click Me


-Rogue

awilson40

Been there, done that. With a little help and info it isnt hard.
But I was slammed so hard for talking about it that My a$$ still hurts from the
email reaming I received from people who sell em for a living.
Dig through old posts and you will probably find all the info you need.

JohnKoaWood

I wonder how long until someone legitimately pops up on the WC board asking what is needed to turbo an N/A..

Some edit code and tune for the sheer fun of it, others because they "need" to..

Some buy turn key kits because they know better, some try to redo what has already been done..

Can the OPs question be answered yes... yes it can, can it be done easily? That all depends on your definition of easy.. to some putting man on the moon was easy... others have issues getting out of bed in the morning...

Rouge knows what he is saying... it can be done, but doing it well is another thing...

Euro951

Thanks to everyone.... so in retrospect you pay money for other peoples research and development which I understand. I also understand now why alot of people don't seem to like the Autothority setup because it uses a resistor to give a fixed Air temp setting.

So basically the autothority setup is just a Ford style MAF which has its output converted by their chipset for interpretation.

JohnKoaWood

http://www.maxhpkit.com/prod_scivision.htm

this is another plug and play solution.. runs pretty well, but is too small for a bigger turbo than stock...

d993

Simple answer:
Others who have already done it and prefer to discourage any attempts at learning how it works by making it sound WAY more complicated than it is and thereby ensuring the $ spent goes into someone else's pocket who has apparently "pioneered" it.....

JohnKoaWood

Oh come on, the main issue isn't one guy or another wanting to keep anyone from trying it themselves... it just comes down to the level of effort to achieve a given goal being beyond the dedication of MOST of the owners of these cars... me..I gotz skills and like doing what I get told can't be done, but that is me...

Yes, you can adapt an off the shelf MAF to one of these cars... but it isn't necessarily easy, nor is it straight forward...

Yes I am running a MAF, YES I am running a DME, Yes I have no piggyback...

Yes I like the performance I got right up until I started blowing MORE oil out of my turbo,, hence my cars current state of togetherness..

Would I recommend my route or Rouges route to the average bear on here, NO I wouldn't because that would just result in more "I'm parting my car" threads...

67King

If it is Craig Moates, it is good stuff. I believe he got his start in F-bodies. He tried to help a few of us 2.3 turbo guys out, but it ended up not working. Glad to see he has expanded, it has been a long time.

But, don't be misled into thinking that you "tune" a MAF like an AFM. LIke I had said, there is a strategy change. There is a whole lot more than just changing a map. And a MAF doesnt' give a rat's but how big your turbo is. Honestly, it doesn't really care how big your injectors are. That's a different part of the code. If you change your airflow map because of a turbo or injectors, you are screwing up your ignition map because your engine is not operating where you are telling your computer it is. There's a LOT left on the table when you do it that way.