getting rid of afm for gm maf sensor?
 

from what i understand, the afm is similar 2 a maf sensor.

it looks like it obstructs air flow a bit(could be wrong)

im going standalone, and id like 2 ditch my afm (cleaner look with my intercooler), and im wondering if i can set up a gm 3 bar maf sensor 2 do the same gob as the afm,

if the gm 3 bar wont work

mabey the lq4?

[IMG]http://i80.photobucket.com/albums/j1...jb1221/lq4.jpg[/IMG]

this sensor would deffinately keep up and not be out dont buy air flow, as ive seen it perform on a 8 second TT grandprix.

is this possiable?

I would like to look into this as well, as I have a hybrid turbo with a 4" inlet, so the AFM becomes quite a restriction in my intake. Of course, going to Microtech or similar would allow me to run a filter or mesh screen on the turbo, but in the mean time........

If you go standalone, you wont need the afm; most of them use map.

well, if you plan on keeping the stock computer to control it, you'll need to compare the outputs of that vs the stock afm for a number of different air flows, and trying different temperatures, pressures etc to figure out what individual variable corrections are needed. Then you'd need to build a signal conditioner (maybe a pic or something along those lines) that takes the output of your new maf, applies all the corrections that you've figured you need, and outputs the corrected air flow to the stock ecu.

For the time and effort that you would put into that (and with the experience that being able to do that would imply), just buy and build a megasquirt and ditch the AFM all together.

why dont u just a get a gm 3 bar map sensor and splice your own connector for it from the boost sensor.

Well i know for DSM's, they've got the MAF Translator that are mainly used for tuning. I dunno to what extent one can tune with it but if they've got it maybe they have something similar for us. But in my own opinion, with the money you spend in that, u can just go standalone for more money and have a better templete for tuning as well as eliminated the MAF, boost sensor etc.

well the good thing about this sensor design is it can be fit in wit 2 4" silicone couplers.


its a 85mm sensor, and the cfm is 900, im not positive on those readings, i have 2 dig up some old tunes with this sensor.

but its non restrictive up 2 500hp, which is less that ill be makeing, but its still nice 2 have less restrictive flow.

plus u can find them on a number of junked cars, (i.e. f-bodys, serrias w/vortech motor, and the old caddy northstars) for about $35 with the wire pig tail.

i have the new ms1 already, its just not tougether yet, im assuming that i would hook it up as you would the gm 3bar, and re-set the air flow table through the tuner to read the new cfm, damn i really cant remember where it maxs out at:confused:

It would be a good idea to read up on engine management before you proceed further.

Don't use the mesh screen. It actually flows worse than a well-designed cone filter.

How bout a ford part.

Read this informative article.

http://howto.globalvicinity.com/gv_w...=120&co=1&vi=1

you seem to be missing the point that an airflow meter is useless if you got stand alone, right?

the mesh screen isnt a filter. Its designed to smooth out airflow entering the maf so that the sensor can get a good signal. Its like the mesh screen on your water faucet. Take it off and the water shoots all over the place. leave it on and it comes out nice and uniform.



BC

Unnecessary, yes, useless.... If you would like the computer to know exactly how much air is entering the engine at any given time then its not useless. Speed density is a very educated guess based on known realities, but its still a guess. A MAF reads actual airflow.


BC

+1

You look really stupid asking questions like that if you don't know what you're talking about.


-Ted

i guess i should have posted which maf

3 bar gm, or lq4?

i think im going with the lq4, i just dont have a damn clue how 2 wire it, i will do some research, but if ne body knows how please enlighten me:)

IBTL!

Someone needs to tell this guy to cut down his damn .sig...


-Ted

i could care less about looking stupid, i care more about being stupid,

the intent of my post was 2 debate which maf would perform better from all of your different experience levels, and perspectives.

ive read up on it quite a bit and feel quite comfortable with most of my sensor choices.

i post with questions 2 decisions that i dont feel comfortable decideing my self with my limited knowledge of the rotary.

as for your post, if your not gonna offer sound advice, and just rag on me(dispite my mis leading titles)

just dont post ne thing at all.

im trying 2 get my car moveing, not talk shit over the computer.

Read his post again. I'm pretty sure he means attaching a mesh screen to the bell mouth inlet of the turbo as seen on some drag cars. I don't see why anybody would want to take the screen off a MAF sensor and attach it to their turbo.

That's an aerator.

What is a 3 Bar GM MAF?

this is the 3 bar,
[IMG]http://i80.photobucket.com/albums/j1...b1221/gm-1.jpg[/IMG]

it requires a vacume tube 2 install, i figured for simplicity reasons, and a cleaner look the lq4 which can couple in, inbetween the i/c pipeing, or b4 the turbo in the middle of the air intake and turbo, it would work better than the 3 bar, with no chance(at least with the hp goal i have 4 my 7) of out flowing the hertz on this sensor( the ability 2 read air intaked air without reaching the static level of the sensors capicity).

its just a better idea in my opinion, i dont want my ecu throwing a 23:1 AFR, with out knowing it.

cuz once you max the maf out, it assumes the car is idleing, and BOOM= rebuild

and yes the screen is 2 even out the air flow so the sensor can read at a stedy level, not to be used as an alternitive for an air filter in a turbo.

shit i guess i really answered my own question, mabey at the price of looking stupid, but id rather be positive of whats going in my car, and not be a fucktard.

i guess the saying for 2day is

"put brain in gear, befor operating mouth"

Standalones use fuel maps, which means you don't need a AFM or MAF

MAF and AFM measure the air mass slightly different so the output voltage will be very different. Infact it would almost be opposite of each other. You would have to design a circuit for the stock ECU to run the MAF instead of the AFM.

But who needs to know that when you want to go standalone :)

I'm going to summarize this very simply:

Can I use a GM MAP sensor to replace my AFM? No.

Can I use a GM AFM/MAF to replace my AFM? No.

Can I use a Ford or anyo other AFM/MAF to replae my AFM? No.

Can I use a GM MAP sensor to replace my boost/pressure sensor? No.

The original poster is trying to solve problems that don't exist due to a lack of understanding. There is no easy and simple way to upgrade the AFM on the RX-7, and indeed there is no need to until you've already upgraded everything else. For a stock turbo car, the stock AFM is fine. Even some upgrades and hybrids when still running on the stock ECU are fine as well.

But if you want to make real power (more then 350HP) you are going to be going to a standalone EFI system anyway. These generally use a MAP sensor to determine engine load.

aaron cake thank you for your stright forward answers,

to clarify, i am NOT running the stock t2 ecu, i will be running a ms1 stand alone, ditching the amf for the lq4 maf sensor.

my initial reason for this post was to determine wather or not this has been done before, and the end results.

thats it thats all i wanted 2 know.

thank you:icon_tup:

That is a 3-Bar MAP sensor, not a MAF sensor. MAP = Manifold Absolute Pressure, MAF = Mass Air Flow. They are completely different items.

When the MAF sensor is maxxed out the computer will assume the engine is maxxed out and will continue the fuel injection rate and ignition timing at the highest load band setting. The reason the engine may pop is because the engine may be operating well above the max setting, causing a lean condition or timing problem. A hot wire, cold wire, or ribbon type MAF sensor is capable of sensing idle airflow. A vane type AFM is not, and assumes idle when the sensed airflow rate drops below minimum, not maximum.

I know that, but I don't think that is what veedubbed was referencing in his post.

More importantly, you may want to read a $30 EMS book before you spend $3,000 on parts that you do not understand. Even better, see the EFI-101 course here:
http://www.efi101.com/index.html

The AEM EFI Basics manual is a pretty good free primer:
http://fordfuelinjection.com/files/A...asics_V1.3.pdf

I know that the megasquirt has been used successfully with a hot-wire afm as opposed to speed-density mode, and MSnS-E even has AFM settings built into it for a specific hot-wire afm. If you're so intent on using an AFM over speed density, this would be the easiest way to go. However, I doubt you'll see much difference between the two methods of calculating air flow.