Apexi s-afc

[rcbear]

Hey guys, anyone install a S-AFC on their P5? I purchase one but i have no reference on any setting for the P5. I will not install the damn thing until i get some hint on the setting. If anyone have any experience in this device and willing to share some setting with me, i'll be very very happy. =)

Zoom Zoom

Derek

[rowan]

There's a thread or two going on the protegeclub board about this issue... you should give them a read..

http://www.protegeclub.com/forum/showthread.php?s=&threadid=5937 (http://www.protegeclub.com/forum/showthread.php?s=&threadid=5937)

http://www.protegeclub.com/forum/showthread.php?s=&threadid=6485 (http://www.protegeclub.com/forum/showthread.php?s=&threadid=6485)

I have a copy of the shop manual if you need to look anything up about wiring.

[ChopstickHero]

rcbear,
what mods have you done for your car that will warrant the use of the apexi s-afc?
it's useless on a stock car..... but it looks cool though ....

[rcbear]

I have change the Japs spec cams on the car. Because the value opening is more and long duration. i need to re-adjust the fuel mapping. that's why i got the S-AFC for the car.

Derek

[rcbear]

Thanks Rowan and ChopstickHero.

Rowan, I have check the forum and it really didn't help much. but there are some interesting things said there. I think i'll install the S-AFC and book a day on the dyno to tune that damn thing. Hope me as a ginny-pig will help others later on.

[DSlayer]

What is the Apexi s-afc

[ChopstickHero]

ok ok
that makes more sense now .... http://msg.toprotege.com/iB_html/non-cgi/emoticons/smile.gif

[DirtyLude]

I've installed about a dozen V-AFC/S-AFC's on Hondas. With the shop manual, as long is it has a fairly detailed pin-out of the ECU harness, it should only take a couple hours to install it. Most of the time getting at the ECU, putting it back, and checking and double checking the wires you're cutting or tapping into.

I have a wideband O2 as well. I don't have a tailpipe probe for it so it may be a pain to install, but given half a day I should be able to tune it as well.

[DSlayer]

can someone answer me I feel left out http://msg.toprotege.com/iB_html/non-cgi/emoticons/baaa.gif

[DirtyLude]

The Mazda engines use a MAF signal which is basicly a swinging door that lets the ECU know how much air is being pulled in by the engine. If the ECU knows how much air is being pulled in and what RPM the engine is running at, it can calculate how much fuel is needed by the engine to run.

The S-AFC intercepts the signal from the MAF and allows you to either raise the signal or lower the signal that the ECU sees by a certain percentage. It allows you to fool the ECU into believing there's more air or less air than actual. It will then adjust fuel to compensate. If you want to lean the fuel out, you can lower the actual MAF voltage using the S-AFC so that the ECU believes it's getting less air and lowers the amount of fuel it injects.

[obender66]

ChopstickHero, 2 liter has almost 10:1 air fuel ratio past 3500 rpm...Getting AFC even on 100% stock car and leaning it out will save some gas. Running too rich hurts performance too. My speculation is that Mazda engineers did reliability overkill in order to allow engine run on 87 octane gas+allowance for piss in gasoline http://msg.toprotege.com/iB_html/non-cgi/emoticons/smile.gif
My question-is there any safeguard in Super AFC against going too lean?
I am not sure if unit comes with A/F ratio meter. It would have to be tuned on dyno monitoring A/F ratio at the same time, what do you think?

[rowan]

Best of luck getting the s-afc working! That is really the last piece of the puzzle to having a FS-ZE comparable engine.
Think about this .. the MP3 makes 10 more HP than normal Protege 2.0 and that is basically all from the ECU program.

[DSlayer]

how much is the s-afc and were do you get it???

[DirtyLude]

This is one of the things that tends to get a huge markup here in Canada. In the US you can usually get Apex'i s-afc's for about $280.00 USD. About $450.00 CDN. If you go to performance shops around here you'll be lucky if you get anywhere near these prices.

These would be a good groupbuy if you could get enough people interested and get someone who could bring them across the border for you.

Like I said, I have a wideband O2 sensor of my own. I don't mind helping out one person tune it if it's not too hard to mount the sensor, I might make up a tail pipe probe. Otherwise you could pay DPE for an hour on their dyno with their wideband. $75.00 for the dyno and $50.00 for the wideband. It might be a better option the first time around to see wether a leaner mixture is actually giving you any extra power.

The S-AFC does nothing for ignition timing, which is another factor in power output.

[rcbear]

I've heard that our ECU is running on OBE2 spec. which the AFC will do nothing... I am just wondering if this is the case. I have to put mine in first to find out. On the AFC manual, there is nothing about FS-ZE or FS-DE engines, so more of a guessing game... Hope you guys can give me some inputs..

hehe

Derek

[DirtyLude]

There's a couple things about the OBD II ECU that you might want to know about with this.

The OBD II ECU has a long term and short term fuel trim value stored. If it decides that the car is running too lean or too rich it will trim the fuel by a percentage in order to get everything in order. The long term trim will take an average of the short term trim over a period of time. With the s-afc you can specify that you only want it to adjust fuel when you have the throttle wide open. This will make it so the ECU doesn't see any abnormal fuel differences unless you're really gunning it and it doesn't even look at the mixture. This will keep the ECU from learning and correcting the adjustments you've made. The ECU also has a backup power wire so that it remembers the fuel trim when you turn off the car. Another option is to cut this backup power wire so it doesn't remember the fuel trims and starts out fresh every time you start the car.

Closed loop. This is when the ECU checks the O2 sensor to decide how much fuel the engine should receive. Closed loop mode only comes on when the throttle is at a steady state for more than usually about a second or two. Cruizing on the highway or down a road. It will not activate above 40% throttle (usually around there on most ECU's) and it will disactivate with any small movement of the throttle. It can't be used all the time because the O2 sensor that it uses is far too slow and innacurate to be able to provide real time feedback when the engine is under high load or the load changes, like when you give more gas.

If anyone gets an autmeter air/fuel gauge or any of the gauges that connect to the stock O2 sensor you'll see closed loop come on when the O2 reading start swinging back and forth from rich to lean like a pinball machine.

[rcbear]

DirtyLude

So, do you mean most of the time, the ECU runs at open mode, which use the MAF to adjust the fuel mapping. If so, then the AFC should do the job. That's what i am hoping cos i spend the money on the device already. just waiting to have time to install it. if not work, it's just another air frestener for my car..haha...

I have readed many different fourms on this topic and i don't know what i am getting into. It seem that everyone knows what they are talking about and everyone has a different understand'g..haha.. scratching my head!!! who know, maybe a Mazda Engineer will show up and explain everything to me and to others...

Thanks all all your inputs. i need to puzzle everything up and stick with a conclusion..!!!

Zoom Zoom

Derek

[DirtyLude]

During city driving most of the time the engine is in open loop mode, using the MAF to look up how much fuel the engine needs. You need to drive for at least two seconds or so without actually moving the gas pedal for it to drop into closed loop mode.

I've done alot of studying on Engine Management and engine tuning in general.  I have quite a few books on the subject.

An excellent site for learning about the basics of engine management is:

http://www.autoshop101.com/

If you look in the technical articles it seperates all the subjects out very well.  It's meant for Toyota vehicles, but almost all of it is generic enough to apply to any car OBD II car.  I know they have an article on closed loop/open loop operation that might help you understand this stuff a little more.

The OBD II technical documents are online somewhere as well.  They're pretty boring, though and hard to apply to what's actually happening in the ECU.

Good luck.