Ricktalife
Member
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- 2012 Subaru WRX
Oh and when I say tuning with the MAP sensor, I mean that the FIC is using its onboard MAP sensor to alter the injector pulse, instead of using the MAF to alter the voltage.
AEM F/IC writeup
- Thread starter Ricktalife
- Start date
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- 03.5 YLW MSP
This may sound like a stupid question but can you tune both open and closed loop with this?
I may be wrong but it seems as if you could only tune in close loop?
Its my understanding that closed loop gives you the most variables to tune with, i.e. o2 sensors, IAT, MAF, etc......while open loop cuts out the use of the o2 sensors as a means to read fuel burning.
Someone else that actually has an FIC could chime in
Its my understanding that closed loop gives you the most variables to tune with, i.e. o2 sensors, IAT, MAF, etc......while open loop cuts out the use of the o2 sensors as a means to read fuel burning.
Someone else that actually has an FIC could chime in
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- 03.5 YLW MSP
Thats what I thought but wasn't 100% sure on that. It doesnt help that I have never messed with any sort of tuning solution. I was mainly curious as he said he would be using the MAP to tune with instead of the MAF.
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- 2003 mazdaspeed protege
yeah I guess we all better hurry and get our hands on the aem fic before the price shoots up on them
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- 03.5 YLW MSP
Im curious to see if this is a better solution then the SSAFC and how well everyone else likes them.
Exactly... the SS AFC has an internal map sensor as well. It uses both the MAP and the MAF... and i know it is altering the MAF signal to change the fuel. I just want to know the draw backs of just using the MAP sensor to control fuel.
Ricktalife
Member
- :
- 2012 Subaru WRX
Open loop: probably not, but I'll try to verify that in the next few days.
Closed loop: Yes
Copied from the AEM manual:
O2 Map (See Figure 35)
At times, such as a track day or race event, you may desire to alter the closed-loop airfuel
ratio (AFR) of the factory ECU to achieve better engine performance. This can be
done using the O2 functionality of the F/IC. By outputting a different signal, the F/IC can
alter the target AFR of the factory ECU. The O2 map “Load Input” can be based on
MAP, MAF, TPS, or O2 sensors. The “O2 Map” also has four different operating modes,
Fixed, Percent, Offset, and Voltage. The load inputs and modes are selected in the “O2”
section of the “Setup” window.
Price wise, it is similar to the AFC. The fuel tuning can also be similar to the AFC, however the FIC gives you more options on how you want to alter the a/f mixture since somebody might prefer not to use the MAF (like me). The excerpt I copied above from the AEM manual is a perfect example of one way the FIC lets you alter the a/f with or without the MAF. Now most people don't care about which way the fuel is leaned out, as long as it gets done. But keep in mind, the FIC can also retard timing like the SSFTC but the price remains the same as the AFC. IMO if you have an FTC, keep it. If you have an AFC and want a little more control but don't want to go full standalone, then check out the FIC.
Ricktalife
Member
- :
- 2012 Subaru WRX
While we are on the topic of fuel tuning... I hooked up my computer during my lunch break today and made some small changes to the fuel map just to verify that everything is working well. While running with no EMS I have had fuel cut pretty much everytime I hit boost, so I have kept my foot out of it. Today I removed some fuel by shortening the time that the injectors remain open, which is done in percentage. To add fuel, you would type a postive value such as 10%. To remove fuel, you would type a negative value such as -10%. Obviously I entered negative values, but decided to make smaller steps. First I put -3% in all cells, and was still hitting fuel cut. So I upped it to -6.5% (roundabout value because the FIC enters weird #'s for an unknown reason, but I'll figure it out) and my wideband was still pinging 10.0 but I noticed a significantly less chance of fuel cut because I was actually able to boost a little bit without bucking. So it is clearly heading in the right direction.
Glad you are up and running Ricktalife.
I think I have given up trying to get the resistance values perfect. It turns out neither the input differential (what the AEM sees vs what the MAF is outputting), nor the output differential (what the AEM says its outputting and the PCM sees) are linear relationships. It appears impossible to tune this car to run like stock with any amount of resistance. I setup my maps based on my calculations last night (holy crap this software sucks). Now my car idles like a champ (maybe better than stock?), but I can't go full throttle anywhere over 3k rpms without cutting out. This is actually worse than the 1.22kohm resistor which didn't cut until 5k rpms.
You might be able to put a 200k ohm resistor on the MAF signal, and another 1M resistor in between which would make the resistance to ground high enough that the AEM's input impedance wouldn't affect the voltage reading, but I think I am done trying to figure out this headache with the resistors, and will just finish my wideband install and tune it.
Most people are best just to ignore the damn MAF signal.
Ok Rick hear me out on this and I could be wrong. You aren't experiencing "fuel cut." If you look at your data logs, you'll see you're fuel did not shut off. What you'll see is a dip in RPM for a split second (200ms), and a dip in MAF reading and fuel. Then it will bounce back a bit, but by that time your foot is off the gas now, and you decelerate.
What I believe is actually happening is we are so rich that the mixture cannot ignite. When that happens it feels like someone took your foot off the gas, and we think it's fuel cut, but it's acutally just the engine not firing. Since it isn't firing, it will start sucking in less air, and the maf signal will decrease and the engine will pull fuel until it fires again. This is the "bucking" we feel.
I am sure our engines will reach an actual "Fuel cut" at some MAF reading, but I doubt any of us without massive turbos and built engines are going to reach it. In fact, I know it's at least 5v because the car did not pull fuel when I hit 5v.
When you pull fuel with the AEM, you'll see that you are able to boost longer because you haven't flooded the engine yet. Keep pulling that fuel until you get into the 11s, and just keep any eye on it. Once you are smooth everywhere, now you can try getting it to 12's across the board.
As to your guy's questions about closed or open loop, yes you can tune either. You can do whatever you want with the AEM. It's just in closed loop the PCM is going to add or remove fuel to get back to stoichiometric exhaust. To trick the PCM, you output a closed loop signal with the AEM, and then you can do whatever you want regardless of throttle position.
They say to only do this at the track, because you can be putting a lot of unburnt hydrocarbons in the air just cruising around with a 10:1 AFR.
I think I have given up trying to get the resistance values perfect. It turns out neither the input differential (what the AEM sees vs what the MAF is outputting), nor the output differential (what the AEM says its outputting and the PCM sees) are linear relationships. It appears impossible to tune this car to run like stock with any amount of resistance. I setup my maps based on my calculations last night (holy crap this software sucks). Now my car idles like a champ (maybe better than stock?), but I can't go full throttle anywhere over 3k rpms without cutting out. This is actually worse than the 1.22kohm resistor which didn't cut until 5k rpms.
You might be able to put a 200k ohm resistor on the MAF signal, and another 1M resistor in between which would make the resistance to ground high enough that the AEM's input impedance wouldn't affect the voltage reading, but I think I am done trying to figure out this headache with the resistors, and will just finish my wideband install and tune it.
Most people are best just to ignore the damn MAF signal.
Ok Rick hear me out on this and I could be wrong. You aren't experiencing "fuel cut." If you look at your data logs, you'll see you're fuel did not shut off. What you'll see is a dip in RPM for a split second (200ms), and a dip in MAF reading and fuel. Then it will bounce back a bit, but by that time your foot is off the gas now, and you decelerate.
What I believe is actually happening is we are so rich that the mixture cannot ignite. When that happens it feels like someone took your foot off the gas, and we think it's fuel cut, but it's acutally just the engine not firing. Since it isn't firing, it will start sucking in less air, and the maf signal will decrease and the engine will pull fuel until it fires again. This is the "bucking" we feel.
I am sure our engines will reach an actual "Fuel cut" at some MAF reading, but I doubt any of us without massive turbos and built engines are going to reach it. In fact, I know it's at least 5v because the car did not pull fuel when I hit 5v.
When you pull fuel with the AEM, you'll see that you are able to boost longer because you haven't flooded the engine yet. Keep pulling that fuel until you get into the 11s, and just keep any eye on it. Once you are smooth everywhere, now you can try getting it to 12's across the board.
As to your guy's questions about closed or open loop, yes you can tune either. You can do whatever you want with the AEM. It's just in closed loop the PCM is going to add or remove fuel to get back to stoichiometric exhaust. To trick the PCM, you output a closed loop signal with the AEM, and then you can do whatever you want regardless of throttle position.
They say to only do this at the track, because you can be putting a lot of unburnt hydrocarbons in the air just cruising around with a 10:1 AFR.
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- 03.5 YLW MSP
Sweet and thanks for the very detailed update, well actually thanks for everyone for taking their time out to get this thing up and running! Another tuning option is a good thing! Now can you tune it to go into a closed loop status any time the presure is lets say -1psi off of the MAP sensor? Sorry if these are very noobish questions but as Ive stated before Ive never really looked into FMU's so I dont know to much about it.
Oh I also wanted to mention that when I started my car this morning I immediately got a CEL. My code scanner said "Crank sensor signal A". I unplugged the harnesses from the AEM and replugged them in and it was fine. When I was messing around with the harness last night I must have pulled it lose a bit, but this may have been the CEL I originally got with the 1.22kohm resistor in place. Simply didn't have a good connection. That's going to be something to watch out for when this is mounted somewhere in the footwell. That's another task that is somewhat daunting. Getting this cleanly put in now with my gigantic patch harness sitting in between the PCM and main harness.
You have the option to output the O2 based on the O2 itself, the MAP, the TPS, and MAF if you have it hooked up. So yeah, you can have it go into closed loop at whatever pressure you want. It's measured in abolsute pressure though, and here in Phoenix it's been about 14.4. So yeah you could output the O2 signal starting at 13.4 psia from the MAP.
Can the FIC tune on the fly? Or do you have to the same as with the SS afc. Turn off the car make your adjustments,load and start and then go.
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speedracer
Member
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- '03.5 MSP
nope you can make running changes
Ricktalife
Member
- :
- 2012 Subaru WRX
@jdwk I think you could be right about it not being fuel cut and yea my wideband was pinging 10.0 when it bucked, so it was drowning itself. I ran a wire from the AEM over to my wideband but it is not connected yet, because I didn't want to bother with it until I had the car running. That's why I only made a small change to the fuel map for now. Tomorrow I hope to accomplish hooking up the wideband to the FIC, reinstalling the ECU under the kick plate, and mounting the FIC in the glove box or wherever it fits best. Depending how long that takes me, I might be able to log a bit as well.
Well since you stated that you are intercepting the crank sensor wires, it is definitely something with the MAF wire that is causing the CEL. As soon as I put the MAF back to stock, I was good to go.
I was pretty sure this was the case but didn't try it yet just to be safe. That's a big plus IMO.
Well since you stated that you are intercepting the crank sensor wires, it is definitely something with the MAF wire that is causing the CEL. As soon as I put the MAF back to stock, I was good to go.
I was pretty sure this was the case but didn't try it yet just to be safe. That's a big plus IMO.
Spent a few hours tonight tuning with the wideband on. I can't seem to completey get rid of the hesitation.
First I adjusted the MAF signal until I was pretty close to 12.0 AFR with no pinging. Then I went to work with the Fuel maps.
I couldn't completely get rid of the hesitation though. Right at 4250 rpms, the AFR goes from sky high 15 to 9.2 immediately. This is our hesitation. I don't know how the car runs at 15, but I guess it's ok at lower rpms. No matter how much fuel I trim at the next point, 4675, it still drops to 9.2. It's infuriating. I got it pretty smooth, almost not noticeable, on one pull, but then made it worst on my next pull.
Yes you can do all of this on the fly, except real time graphs would be really helpful. After every pull, I'd pull over, save the log file. Import the log file to AEMLog, then see what was up with only three graphs at a time.
I bought some T taps to put in the LC1. I think I am going to redo my harness so I can quickly switch from AEM's maf output, to pure maf to ecu. I want to see what my AFRs look like stock with the wideband. Even though I got it running well with the MAF going through the AEM, I still wonder if it's making this harder on me. The reason is because the inj% was hitting 94 at peak tonigh. But when I logged the maf tapped by the aux in but otherwise going straight to the ECU the other night, the highest inj% I hit was 70. Maybe I was lean, but I don't remember any pinging.
Well, I'll keep this thread updated with my progress.
By the way, this is the first time I've ever experienced pinging first hand. It really isn't that noticeable in our cars. It kind of sounds like some small gravel is being thrown up into the engine bay, not nearly as the violent as the "marbles in a blender" description I've been told before.
First I adjusted the MAF signal until I was pretty close to 12.0 AFR with no pinging. Then I went to work with the Fuel maps.
I couldn't completely get rid of the hesitation though. Right at 4250 rpms, the AFR goes from sky high 15 to 9.2 immediately. This is our hesitation. I don't know how the car runs at 15, but I guess it's ok at lower rpms. No matter how much fuel I trim at the next point, 4675, it still drops to 9.2. It's infuriating. I got it pretty smooth, almost not noticeable, on one pull, but then made it worst on my next pull.
Yes you can do all of this on the fly, except real time graphs would be really helpful. After every pull, I'd pull over, save the log file. Import the log file to AEMLog, then see what was up with only three graphs at a time.
I bought some T taps to put in the LC1. I think I am going to redo my harness so I can quickly switch from AEM's maf output, to pure maf to ecu. I want to see what my AFRs look like stock with the wideband. Even though I got it running well with the MAF going through the AEM, I still wonder if it's making this harder on me. The reason is because the inj% was hitting 94 at peak tonigh. But when I logged the maf tapped by the aux in but otherwise going straight to the ECU the other night, the highest inj% I hit was 70. Maybe I was lean, but I don't remember any pinging.
Well, I'll keep this thread updated with my progress.
By the way, this is the first time I've ever experienced pinging first hand. It really isn't that noticeable in our cars. It kind of sounds like some small gravel is being thrown up into the engine bay, not nearly as the violent as the "marbles in a blender" description I've been told before.
Ok what I really want to know is what the F is going on with the stock maps. Why in the world do they do this? Is it still in closed loop until 4250 rpms? Is it related to the VICS or VTCS?
But from my understanding, AFR's should be constance regardless of RPM.
Here's a picture of what I am talking about. I even tried looking through the SSAFC threads to see what they did to solve this, but forums aren't good for digging up information. It's like a needle in a haystack.
But from my understanding, AFR's should be constance regardless of RPM.
Here's a picture of what I am talking about. I even tried looking through the SSAFC threads to see what they did to solve this, but forums aren't good for digging up information. It's like a needle in a haystack.
Ricktalife
Member
- :
- 2012 Subaru WRX
Well I haven't done any datalogging yet so I have no idea how to comprehend the maps lol. But I do know that open loop kicks in around 4k so I would say it's accurate.
edit: Are the injectors supposed to be operating at such a high duty cycle? I think that is the problem because you can see it lean out in a hurry once you hit open loop. I adjusted my injectors by about -6% so far and it can still hit 10.0, but it can't be going far under that because it doesn't buck like it did when running the stock map. These cars are tuned way rich from the factory, and adding modifications like intake and exhaust doesn't help the matter. That's why EMS is pretty much a requirement.
edit: Are the injectors supposed to be operating at such a high duty cycle? I think that is the problem because you can see it lean out in a hurry once you hit open loop. I adjusted my injectors by about -6% so far and it can still hit 10.0, but it can't be going far under that because it doesn't buck like it did when running the stock map. These cars are tuned way rich from the factory, and adding modifications like intake and exhaust doesn't help the matter. That's why EMS is pretty much a requirement.
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