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MAF adjusting?
Originally Posted by Nick_d_TII
(Post 10333226)
A few of us RTEK guys are having a few issues with maxing the AFM airflow reading and are curious if we can get more fuel by Modding the S4 AFM... Anyone done this?
From random website on Toyota 22re AFM: "The AFM mod involves cutting the silicone seal on the black cover to gain access. Once inside, there's a "curly brace" looking metal clip in the upper left corner being held down by a Phillip's screw. Mark with nail polish or similar, the original position of at least one of the ends. Then, WHILE HOLDING THE LARGE GEAR WHEEL, loosen the screw allowing the metal clip to go slack. Turn the gear wheel clockwise to lean the running mixture, and counter-clockwise for richer. The idle mixture is largely unaffected by this adjustment. Do not adjust any more than 3 teeth in either direction with a stock system. Once you have the gear wheel where you want it, tighten the Phillip's screw again to make the metal clip hold the wheel in place. Supposedly, a stock system shouldn't need any adjustment, and won't benefit much from changes. It's a trade-off; leaner helps off-the-line, richer adds to the top-end." "To control the movement of this flap/aramture, the AFM is fitted with a flat-wound spring that is used to apply tension to the flap. This spring is held in place, and adjusted, via a plastic gear and a wire "holder". When this gear is tightened (turned clockwise) relative to the flat wound spring inside of it, it becomes harder for the door to open, and this translates to a leaner mixture (more air needs to flow in to move the door by a given amount, meaning theat the mixture is leaner relative to its starting point before adjustment). Turning the gear counter-clockwise has just the opposite effect, as the looser gear lets more air in relative to "stock". Remember: Turning the gear CLOCKWISE LEANS OUT THE MIXTURE. Turning the gear COUNTER-CLOCKWISE RICHENS THE MIXTURE Generally speaking, each tooth of the gear is equal to about a 2% change in the transient mixture (with stock injectors)." http://www.flickr.com/photos/7118909...7594284969847/ ATM the FC is my DD while I soak up the fuel cost and the new brakes for my jeep. So I cant risk my DD and afford a wide-band atm... but I am VERY interested in doing this and wonder if anyone has tried this. Leaning out my N/A would increase power (it runs RICH) I'm sure. And want to test this.... Anyone willing to help figure out if this works? |
I don't know about physically modifying the AFM to lean it out.. But I did just install an SAFC2 on my car a little while ago and leaned it out to -15% on low RPMs, low load [dirty cone filter with no cold air shielding, full Racing Beat collected NA exhaust, otherwise stock]. I got 23.4MPG overall on the tank with probably 65%-75% freeway driving..
Edit: if you haven't read about SAFCs before, what they do is intercept the air flow signal and modify it. Also if you get one and install it, use the pressure sensor signal wire instead of the TPS.. At least for S4s |
there is no reason it shouldnt work. I have taken apart the AFM also, and you can change the tension on the spring. It only works for S4 AFMs, but you can easily swap these onto S5 using the pinout in the FSM. I havent actually tried tuning with it though
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it will work on the S4 afms. when you gently pop off the cover, take some paint and mark where stock is. the older afms actually have a adjustable stop @full open, and i think that adding this to the FC afm would be a big help too.
so you can adjust spring tension, and if you add a stop @full open, you can just adjust full throttle too. i put a wideband on my S4 though, and i found that in stock form, its not rich at all |
installing an S-AFC is a much better option than this.
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