Calum

Ok, this is a longshot, but have any of you guys worked with an AEM? I've got some problems with one right now and have some real general questions. This thing is a big learning curve.

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All posts by Calum in this thread are copyrighted by Calum, and cannot be edited, deleted, or copied without his express permission.
calum@calumsult.com

 

coalitionSE-L

What's up?

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1999 SE-L SR20DET-- Sold!
1997 Maxima-- The bone-stock family machine!
2004 Xterra-- The wife's ride!

HJBarker

I've used EMS on a 1st generation Mitsubishi, so, I have a little bit of working knowledge... what's happenin'? ///H

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...another thread invasion from Harry, who came back and noticed that everything was suddenly fcuking different. What happened?
Not on the forum much lately since neck injury - we'll be back at it soon, babying the n00bies.

JWT S4, HS 6, Home Depot Intake, Hypercoil 2s w/ KYB "GR-Poo", CF Sunroof Delete panel, and other crap - where's my interior?

Calum

Ok, here's the situation: I spent the weekend wiring in the AEM to a '93 Supra. We put in a 5 bar map sensor, GM temp sensor, 800cc SARD injectors, and removed the stock ignitor box and added AEMs CDI box. I also modified the driver board inside the AEM EMS box to work with the no ignitor setup per AEMs instructions and have the CDI box supposedly set correctly for this. The wiring looks really slick, all thats left is to add a real circuit for the power to the CDI box, but the rest came out really well.

So much for pretty, right now it doesn't work. We've got a tune from some dude thats got a similair setup but it doesn't run. The car will start but will not idle or run worth a crap. You have to stay on the gas pedal just to keep it running. When moving its very sluggish with no power. I think what I'm going to do tonight is first verify that each cylinder is actually getting spark and that they're in the right sequence. I think I've got the CDI wired correctly but if I screwed up thats where it would be. That required a fair amount of hacking on the stock harness. Hindsights 20/20: we should have just installed the EMS and then the CDI box. Oh well. Anywho, this morning we took the stock supra base from AEM and have changed it to work with the new injectors and map setup; I'll try running the car with this next. How does that plan sound to you guys? Is there anything obviously wrong from your experience with the EMS that would make the car run (or lack thereof) the way it is?

Ok, here's my questions about the software. Well, first question, is there a webpage with clear instructions on how to actually use the software? AEMs helpfile isn't very good. I've got the latest version of the software and firmware installed correctly. Each time launch the software it wants to bring up the old cal file. How do I set it up so it doesn't do that? Thats annoying. Also, how do I make changes realtime without having to turn the car off and upload the cal file? Finally, how exactly do you tune the idle? Do you change the % vs rpm map thingie?

Thoughts, suggestions?

Btw, when the car acutally runs its a blast. Big single turbo, HKS cams, lots of fun. The cams idle rough too, that makes figuring out if the car is actually running properly a pain.

coalitionSE-L

Calum, my suggestion would be to start with the base map and configure it according to the particular setup. Using other peoples' calibrations can introduce many problems that you will have to additionally troubleshoot.

Anyhow, the first thing I'd like to mention is that the AEM instruction manual is definitely ambiguous and unfortunately, the info found on the forum is even more ambiguous. There is definitely a learning curve here like you said. Hopefully I can shed a little light on some things for you.

Starting with the base calibration, insure that you changed the injector size and fuel pressure correctly. Not only do you change the battery offset data in the wizard, but you must also change the injector size/fuel pressure in the fuel map itself. To do this, open the fuel map in table view. Right click anywhere in the map and select "change injectors/pressure." You will enter the stock injector size and fuel pressure setting as well as the new injector size and setting. The fuel map is automatically rescaled after this is done.

Next, insure that you configure the calibration for the ignition that you are running as per the instructions. Not sure how to do this myself because I'm not doing it, but I know that the instructions tell you what to do.

Next, changes cannot be made by the end user in real time. You must make changes and then upload them. However, there is an automapping feature that you can use for automated changes to your fuel map (for target AFRs) in real time. I can explain that to you if you'd like.

I'd say focus on getting it started and running on the base calibration that is correctly modified for the new injectors and ignition. If you still experience idling issues, we can delve into that at another time. BTW, each time you open the EMS software, it brings up the last cal that you worked on. That's a default thing.

Let me know if you need any more info, I'll be glad to try and help.

Calum

Expect more questions tonight. I am such a newb at this, but its a really neat toy. I'm tempted to buy one for one of my cars just to play with.

Edit: Two quick questions.

1st, we don't have a wideband hooked up right now. We've got the AEM, but I haven't installed it yet. Whats the O2 scaling thingie uder the O2 menu? The only options are for different wideband types. Do I need to change anything since its using the stock non-wideband O2 sensor?

2nd, can you elaborate on how the self-learning works? I'm surprised you can't make changes on the fly, thats something I can do with the stock Nissan ecu.

coalitionSE-L

Calum, I forgot to touch on the most important part of getting a car running on the EMS--startup. There is a very involved startup process that you must go through in order to insure that the car runs properly. I don't know if you did this or if you even know about it, but I will explain it in detail just in case. After you have modified your base calibration to the current configuration and uploaded it to the unit, do the following:

First be sure that the throttle has been setup. Connect with the EMS first. Go to the "Configure" menu and select "ECU Setup" and then "Set Throttle Range." Follow the instructions to set the throttle range. It is very self explanatory. No go on to the following:

1. You need to insure that the cam and crank angle sensors are synchronized. To do this, connect with the EMS. Go to the "Options" menu and select "Injector." Uncheck active for every injector being used. Next, go to the "Templates" menu and select "Home." There will be a parameter called "Sync" or "Stat Sync." It should be off. Crank the engine and verify that it turns on within a few seconds.

2. Next you need to verify timing. To do this, connect a timing light to #1. All injectors should still be inactive. Go to the "Engine Start" menu and select "Options - Engine Start." Set the "Crank Adv" value to whatever base timing is desired, but make sure that it coincides with a marking on the crank pulley. Be sure to note what the "Crank Adv" value is before you change it, you will have to set it back later. Next go to the "Configure" menu and select "ECU Setup" and then "Set Ignition." Crank the engine. The engine timing seen from the timing light should match the "Ign Timing" parameter in the "Set up Ignition Timing" window. If there is a discrepancy, use the "advance" or "retard" buttons to make the timing light match the displayed value. The advance and retard buttons affect actual engine timing, so the difference will be seen in the timing light, not the displayed parameter. Whenever the values match, click OK.

3. After these things have been done, be sure to save the calibration as a new name and note that these things were done in the notes. Turn the injectors back on and set the "Crank Adv" parameter back to its original setting.

4. Now it is advisable to sync ignition timing while the engine is running at low and high RPM. To do this, connect the timing light again to #1. Connect to the EMS (if you disconnected for any reason). Go to the "Ignition" menu and open the ignition map in table view. Either copy the ignition map or do something that will enable you to reset the values after this is done. Set the ignition advance really conservatively (you'll be revving near the rev limiter). You may want to disconnect the wastegate or put it full open somehow depending on the setup. Go to the "Ignition" menu again and select "Advanced Ignition" and then "Ignition Trims." Set all the ignition trims to zero--but take note of the settings before this is done so that you can reset them. Go to the "Configure" menu and select "ECU Setup" and then "Set Ignition." Start the engine. Be sure that the light and the displayed parameter agree once again and make the necessary adjustments if they don't. When the values match, click OK. Now rev the engine near the rev limiter (this is why the timing needed to be conservative). Verify the ignition has not moved around. If the timing is not synced at high RPM, adjust the "Pickup Delay Comp" option until the "Ign Timing" parameter and the light match. After that, reset all ignition trims and the ignition map. Save the calibration again as a new name and make notes as to what has been done.

coalitionSE-L

1. If you are using a unit with the U (i.e. 30-1600U) on the end of the model number, you need to put the UEGO wideband in place of the first O2 sensor (stock O2 sensor), since the calibration is configured for that by default. The "U" units have a separate plug for the UEGO on the side and they take readings from that. If it is not a "U" model, just select the proper O2 sensor in the wizard for now. You don't want to screw with anything like that just yet.

2. I don't have time to go into automapping just yet because I have to go to work, but when I get home, I will give a write-up on that for you as well. It is pretty easy once you get the car up and running.

Calum

We got the car running over lunch. We switched to the modified base AEM supra tune and it runs! We should have done that from the begining. At least that means I wired and modified the EMS box correctly.

I did the TPS calibration last night, I'll do the timing stuff tonight. I think I'm going to wire up the wideband too if I get the time. I'll take some pics too, its a pretty car.

I'm looking forward to your post on the automapping.

Calum

On a side note, I think people intrested in tuning the stock nissan ecu should read this thread:

AEM Boost Comp thread

The details are not important. What is important is you can do the exact same principle on the nissan ecu.

JayLew

Thats how Enthalpy tunes his fuel maps. Or at least it is on the copy that I have.

Its easier to understand how the fuel map works when you see it in a linear way.

Thanks for the link

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Jason

1992 240SX
2006 WRX (wingless non TR)

coalitionSE-L

OK, so now on with a couple of tuning features available with the EMS. I'll cover Automapping as well as O2 Feedback. Both of these are utterly useless if you are not using a wideband O2 though, unless you just want 14.7:1 across the board--but obviously you don't. So be sure to get that wideband hooked up.

The internal datalogging feature of the EMS is an extremely helpful tool and can obviously be used for tuning--if you want to tune on a cell by cell basis after a road test. That is quite tedious though, and the aforementioned methods alleviate a great deal of the tedious process. Anyhow, here goes:

Automapping

The automapping feature, in a nutshell, allows the end user to specify target AFRs throughout the RPM/load range of the fuel map, and makes automated, real time changes to the fuel map on a road test to meet those targets. This feature makes the fuel tuning process very easy. There are basically four windows utilized for this process in the AEM software: "Automap Fuel Log Map," "Fuel Target," "Fuel Map," and "Auto Mapping."

To preface how this works, it is important to understand the structure of the table views of the various maps--specifically fuel and ignition. You surely will not have any problem with this, Calum. You'll want to configure the resolution of these maps first, before doing any tuning. The default maps have the RPM scale going all the way to 10,500. Obviously, the Supra is not going to see that, so reconfigure the maps to your liking (with the load axis as well). This will allow you much richer resolution for tuning. Your final config will be reflected in all associated maps that use RPM vs. Load axes.

Now, the Automapper logs in the "Automap Fuel Log Map" (duh) what is really happening with your AFRs. The "Fuel Target" map is set by you. Both of these maps are structured exactly like the fuel map, RPM vs. Load with individual cells for each combination in your resolution. The difference is that the value in the cells of these two maps is the AFR as opposed to injector data in the fuel map.

Now with all that being said, let's begin automapping. First you need to connect the AEM software with the EMS. You also might want to make sure that your base fuel map is a bit on the rich side just as a precaution. Maybe take the car for a spin and datalog the run. Make any adjustments to the base fuel map that you deem necessary to insure it is a safe starting point. Go to the "Fuel" menu and select "O2 Sensor feedback" and then "Options - O2 Sensor FB." Verify that "O2 FB Control" is unchecked. Now go back to the "Fuel" menu and select "Automap Fuel Log" and then "Target." Here is where you set your desired values. If you know where you want to be for every cell individually, then go to town. If not, maybe just set the whole map to 12.5:1 or something like that as a start. Now go back to the "Fuel" menu and select "Automap Fuel Log" and then "Log." Right click anywhere in that map and select "Initialise Auto Mapping." The "Auto Mapping" dialog box appears. I will tell you a good initial configuration for this box, but first I'll explain the nitty gritty of the different parameters because I know you'll want to play around with them later.

The "Auto Mapping" dialog box basically tells the automapper what to do and when to do it. 1. Weight Before Change The "Weight before change" value determines the cumulative weight of values collected for a cell before any modification is made to the base fuel map. In other words, if it were set to 5, then it would not make any changes to any individual cell until at least 5 readings were taken for that specific RPM/load combination. To understand why you would want different values for this, you must know how the automapper determines values for each cell. Each cell's displayed value is actually an average of all the readings taken for that particular cell. The higher the weight before change value, the more data the EMS has collected to make a modification from. 2. Target Accuracy The "Target Accuracy" value is the minimum absolute difference between a logged value and a target value required for the Automapper to make a modification. This is a +/- value. In other words, if it is set to .5 and a specific cell has a target value of 12:1, then the Automapper will only modify the base fuel map if the logged value for that cell is greater than 12.5:1 or less than 11.5:1. If the "Weight Before Change" and "Target Accuracy" conditions are met, then automapping will modify the particular cells that meet that criteria.

The next values in the "Auto Mapping" dialog box determine the constraints of the changes made by Automapper. The "Error Multiplier" and "Error Additive" are variables in the equation that Automapper uses when making changes to the base fuel map. The equation is as follows: Change = (Target Map value - Log Map value) * Error Multiplier + Error Additive. The specifics on these numbers could take up an entire thread so I won't go into them right now. Don't worry though, I'll give you some good starting values.

Lastly, the "Max Percentage Change" and "Max Absolute Change" values are the final constraints. They are pretty self explanatory as in the Automapper will only change the cell values in the base fuel map as much as these values.

Now back to what we were doing. Configure the "Auto Mapping" dialog to your liking. A good starting point is the following:

Weight Before Change: 5
Target Accuracy: .3
Modify Base Map by: Percentage
Error Multiplier: -7
Error Additive: 0
Max Absolute Change: +50, -10
Max Percent Change: +50, -10

Now open the base fuel map. You should be viewing three windows total: "Automap Fuel Log Map," "Fuel Target," and "Fuel Map." Right click in the "Automap Fuel Log Map" and click "Start Automapping." Go driving! You should notice after a while that changes are being made to the base fuel map. Be sure to get the engine in as many different RPM/Load combinations as possible to change as many cells as possible. When you are done, right click "Automap Fuel Log Map" again and click "Stop Automapping." The base fuel map should have been changed.

You can continue to do this over and over again until your AFRs are where you want them. The cool thing about Automapper also, is that it only makes changes at 5% throttle or above so decel maps and idle maps are not affected at all.

I will discuss O2 feedback in my next post. Hope this helps you with Automapper. Let me know if you have any questions.

coalitionSE-L

O2 Feedback

O2 Feedback tuning can be useful, but in my opinion it is more dangerous and less helpful than Automapping. The reason for this is that when O2 Feedback is enabled, the EMS operates in a closed loop. If the O2 sensor fails or malfunctions under high load, lots of damage can potentially occur as you are probably well aware. Anyhow, I will touch on it regardless since it could come in handy for some types of tuning (like possibly fuel economy). Note: I am not going to delve into the Zeigler Nichols Tuning Method using O2 Feedback because I feel it is too tedious and there are too many better options with the EMS. I will explain simply using the target map.

Connect to the EMS. Go to the "Fuel" menu and select "O2 Sensor Feedback" and then "O2 FB Target Map" in table view. This brings up a simple target AFR map using RPM vs. Load axes. In this table, you can enter all your desired values and the EMS will adjust your fuel map to meet these while running in closed loop.

Next, go back to the "Fuel" Menu and select "O2 Sensor Feedback" again and then "Options - O2 Sensor FB." Check the "O2 FB Control" box to put the EMS into full time closed loop. Configure the datalogger to run while you take the car for a test drive. The easiest way to do this is to go to the "Setup" menu and select "Internal Logging." A dialog box appears. Check "Log Always" and "Loop Logging." You might want to adjust the rate of logging at the bottom of the dialog box to give yourself more log time.

Go drive the car and come back when you feel you have enough data. Study your datalog, specifically the injector duty cycle for specific RPM/Load combos. Go back into your base fuel map and make changes according to this data because this is what is needed to achieve those desired AFRs that you entered in the target map. Get out of closed loop mode, you're done.

I'm sure you'll agree that for major tuning, Automapping is much better, but O2 Feedback tuning could come in handy here and there.

Calum

This thread needs to be a sticky.

Calum

Lol, please don't. The last controls class I had was when I was an undergrad and I've avoided them ever since. I'm an electrical engineer btw, whats your background?

coalitionSE-L