Axing the flapper style mas air meter
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Axing the flapper style mas air meter
I was wondering if anyone knows of a cost effective (cheap) way to get rid of the flapper style M.A.S., like a hotwire setup or changing it to a map sensor without going full stand alone???????
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Man, this has been reviewed and pondered on many times. And, there really isnt any way, that i can think of, that is any easier or cheaper than a stand alone. But i, too, would like to know the answer. I hear of people trying to use Mustang MAF bc they are bigger or some ****, but i dont think anyone has really suceeded with it due to the wireing is totally different.
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There is a company called pro-m that was willing to build me a hot wire setup w/ idel and w.o.t. fuel adjustments. They would also make it any dia. i wanted but they wanted like $700.
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Oh yeah, my car is a 88' T2 and I have a 62-1 turbo that i want to install, but the intake opening on it is 4" and it would be stupid to have it neck down to the stock flapper.
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The reason I haven't gone with a stand alone is I want to do a three rotor in the near future and would hate to buy stand alone twice...What do you know about the E.M.S or Electromotive setups. If I could find something that was upgradable to a three rotor I might get it.
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Originally posted by Bad2ndgen
The reason I haven't gone with a stand alone is I want to do a three rotor in the near future and would hate to buy stand alone twice...What do you know about the E.M.S or Electromotive setups. If I could find something that was upgradable to a three rotor I might get it.
The reason I haven't gone with a stand alone is I want to do a three rotor in the near future and would hate to buy stand alone twice...What do you know about the E.M.S or Electromotive setups. If I could find something that was upgradable to a three rotor I might get it.
If you are on a tight budget, then you can forget about the 3-rotor. Sorry.
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I am very aware of the costs associated with doing a three rotor conversion, I just dont want to spend money on things that will become obsolete when I do the swap....It will be about a year before I start this project and I want to enjoy my two rotor without spending too much more than I already have. I was under the impression that AEM has discontinued the EMS race version untill a later date, so that idea is out for now. I talked to Ray Lockhead last weekend and he said that the Electromotive Tec3 would be upgradable from two to three rotors but I didn't get to talk to him at lenght about the details. Anyway back to the topic of this thread Im still looking for a (cheap) fix for my M.A.S. My current motor will be going into an R100 if I can find one, as soon as I do I will start the 3rotor project. If you want to know Im not full of **** just check out my car at www.kennewickimports.vista.com
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You could get a Haltech now... it would work with the 3-rotor. You could then add a second IGNITION ONLY computer to run the trailiing. (Haltech also makes one of those... not too expensive.) Just a thought.
Brad
Brad
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One thing I'm fixin' to experiment with is moving the AFM to the intercooler piping. It's much less of a restriction than before the turbo, and it's a really popular mod in Japan - there are countless FC's making 400-500 hp with the stock AFM in the IC piping - gotta be something to it .
You can upgrade to the '89-91 airflow meter - all you need is the airflow meter and the plug. I put it on my '88 Turbo and had NO problems - it started and ran just fine, made great power, you name it, with no tuning to the AFM signal or anything.
I really wish there was a "good" AFM solution for the RX-7. AFM's have a big advantage in that they calculate the volume of air directly. With a MAP based system, it estimates air volume by manifold pressure, throttle position, and RPM, with a set volumetric efficiency for the motor. When you alter the motor's volumetric efficiency, the whole map goes outta wack. That's why the FD guys have much trouble when upgrading their cars and need a computer early in the game. Same goes for a Haltech - you have to redo the maps when you make changes to the VE of the car, although it isn't as radical, since you're usually starting with a free-flowing system, not a choked-up factory system.
Anyhow, some food for thought.
Dale
You can upgrade to the '89-91 airflow meter - all you need is the airflow meter and the plug. I put it on my '88 Turbo and had NO problems - it started and ran just fine, made great power, you name it, with no tuning to the AFM signal or anything.
I really wish there was a "good" AFM solution for the RX-7. AFM's have a big advantage in that they calculate the volume of air directly. With a MAP based system, it estimates air volume by manifold pressure, throttle position, and RPM, with a set volumetric efficiency for the motor. When you alter the motor's volumetric efficiency, the whole map goes outta wack. That's why the FD guys have much trouble when upgrading their cars and need a computer early in the game. Same goes for a Haltech - you have to redo the maps when you make changes to the VE of the car, although it isn't as radical, since you're usually starting with a free-flowing system, not a choked-up factory system.
Anyhow, some food for thought.
Dale
#14
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The AFM's output would have to be tailored for what the ECU expects, which is a certain voltage that correlates with a certain airflow. This may not even be possible, since the way a sliding cone or flapper door reacts to airflow is different than a hotwire. I know of many people who have tried, but none to my knowledge have been successful.
Regardless, I think the '89-91 AFM isn't as bad as one would think - going back to my example of the many Japanese cars with the AFM in the intercooler piping.
Dale
Regardless, I think the '89-91 AFM isn't as bad as one would think - going back to my example of the many Japanese cars with the AFM in the intercooler piping.
Dale
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thanks for the info.....do you know what it takes to move the afm to the piping, I heared it takes some kind of modification. Do you know anything about this?
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Originally posted by Bad2ndgen
thanks for the info.....do you know what it takes to move the afm to the piping, I heared it takes some kind of modification. Do you know anything about this?
thanks for the info.....do you know what it takes to move the afm to the piping, I heared it takes some kind of modification. Do you know anything about this?
Dale
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Originally posted by rx7_ragtop
What about adapting a Mustang hot-wire AFM? Just a thought...
Brad
What about adapting a Mustang hot-wire AFM? Just a thought...
Brad
The Megasquirt just made it not worth finishing, because you get a standalone fuel computer.
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Originally posted by David88vert
It's not easy. Yes, it's doable, but for the effort and cost of doing it, you are better off to get a MegaSquirt and go with a MAP. If you want to try the Mustang MAF, there is a lot of documentation on it, and I have a new Mustang MAF here that I was experimenting with.
The Megasquirt just made it not worth finishing, because you get a standalone fuel computer.
It's not easy. Yes, it's doable, but for the effort and cost of doing it, you are better off to get a MegaSquirt and go with a MAP. If you want to try the Mustang MAF, there is a lot of documentation on it, and I have a new Mustang MAF here that I was experimenting with.
The Megasquirt just made it not worth finishing, because you get a standalone fuel computer.
Brad
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http://www.corral.net/tech/powerplant/maf_tech_2.html
http://www.corral.net/tech/powerplant/mafrelocate.html
The above references tell you about the wires off the MAF. You will need the RX7 FSM and the Mustang FSM for all of the exact values and computer measurements.
Oh yeah, I was using a 2000 4.6 MAF
http://www.corral.net/tech/
http://www.corral.net/tech/powerplant/mafrelocate.html
The above references tell you about the wires off the MAF. You will need the RX7 FSM and the Mustang FSM for all of the exact values and computer measurements.
Oh yeah, I was using a 2000 4.6 MAF
http://www.corral.net/tech/
#20
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I remember someone taking off the AFM and taping the little flapper thing so the ECU thinks its at WOT and just leaving the AFM there and put the filter over the turbo, but the engine blew. If you taped the flapper thing all the way to WOT and used a SAFC to lean/richen fuel mixture. Or hook up the flapper thing to the throttle linkage somehow and use a SAFC. might be a stupid idea tho.
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It does work, I hvae done ( sortof). the hard part is to get it to open at the same rate it does if it wer moving air. Meaning it need to be in the same position at 50% trottle as it would at 50% useing it the right way. then when youy get that figured out you simply run a throttle cable to where the AFM sits normaly and you are done. I am almost to that point, but I had to move and now we are painting the house and stuff. everything has been put on hold. A better idea is to reverse ingineer a manifold pressure sensor to work with our computer.
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Originally posted by dcfc3s
One thing I'm fixin' to experiment with is moving the AFM to the intercooler piping. It's much less of a restriction than before the turbo, and it's a really popular mod in Japan - there are countless FC's making 400-500 hp with the stock AFM in the IC piping - gotta be something to it
One thing I'm fixin' to experiment with is moving the AFM to the intercooler piping. It's much less of a restriction than before the turbo, and it's a really popular mod in Japan - there are countless FC's making 400-500 hp with the stock AFM in the IC piping - gotta be something to it
Originally posted by dcfc3s
You can upgrade to the '89-91 airflow meter - all you need is the airflow meter and the plug. I put it on my '88 Turbo and had NO problems - it started and ran just fine, made great power, you name it, with no tuning to the AFM signal or anything.
You can upgrade to the '89-91 airflow meter - all you need is the airflow meter and the plug. I put it on my '88 Turbo and had NO problems - it started and ran just fine, made great power, you name it, with no tuning to the AFM signal or anything.
http://fc3s.org/
S4 AFM Fully Closed = 200-600 Ohms
S5 AFM Fully Closed = 200-1000 Ohms
S4 AFM Fully Open = 20-1000 Ohms
S5 AFM Fully Open = 20-800 Ohms
Yes, it may work, but it will obviously not work correctly until the resistances are corrected with the appropriate homebuilt circuit. Even then you will still have the same non-programmable slow S4 ECU (half the processor speed of the S5) running your engine. Not worth the trouble IMO.
Originally posted by dcfc3s
I really wish there was a "good" AFM solution for the RX-7. AFM's have a big advantage in that they calculate the volume of air directly. With a MAP based system, it estimates air volume by manifold pressure, throttle position, and RPM, with a set volumetric efficiency for the motor. When you alter the motor's volumetric efficiency, the whole map goes outta wack. That's why the FD guys have much trouble when upgrading their cars and need a computer early in the game. Same goes for a Haltech - you have to redo the maps when you make changes to the VE of the car, although it isn't as radical, since you're usually starting with a free-flowing system, not a choked-up factory system.
I really wish there was a "good" AFM solution for the RX-7. AFM's have a big advantage in that they calculate the volume of air directly. With a MAP based system, it estimates air volume by manifold pressure, throttle position, and RPM, with a set volumetric efficiency for the motor. When you alter the motor's volumetric efficiency, the whole map goes outta wack. That's why the FD guys have much trouble when upgrading their cars and need a computer early in the game. Same goes for a Haltech - you have to redo the maps when you make changes to the VE of the car, although it isn't as radical, since you're usually starting with a free-flowing system, not a choked-up factory system.
There IS a good AFM solution - aftermarket EMS units from Electromotive, Haltech, Microtech, Motec, Wolf, etc. Maybe they can't run closed-loop in any condition other than cruise, but they DO allow for a Speed Density or Alpha-N setup which is basically the same concept as putting the AFM after the intercooler, except that they have much better processors than the ancient stock S4 and S5 ECU.
Originally posted by rx7_ragtop
What about adapting a Mustang hot-wire AFM?
What about adapting a Mustang hot-wire AFM?
Originally posted by tweaked
It does work, I hvae done ( sortof). the hard part is to get it to open at the same rate it does if it wer moving air. Meaning it need to be in the same position at 50% trottle as it would at 50% useing it the right way. then when youy get that figured out you simply run a throttle cable to where the AFM sits normaly and you are done. I am almost to that point, but I had to move and now we are painting the house and stuff. everything has been put on hold. A better idea is to reverse ingineer a manifold pressure sensor to work with our computer.
It does work, I hvae done ( sortof). the hard part is to get it to open at the same rate it does if it wer moving air. Meaning it need to be in the same position at 50% trottle as it would at 50% useing it the right way. then when youy get that figured out you simply run a throttle cable to where the AFM sits normaly and you are done. I am almost to that point, but I had to move and now we are painting the house and stuff. everything has been put on hold. A better idea is to reverse ingineer a manifold pressure sensor to work with our computer.
I don't see how the pressure sensor would work with an ECU which is looking for an air volume signal. Maybe you can explain that one?
A better idea is to spend your time painting someone else's house, make some money, and buy an aftermarket standalone EMS.