AEM Engine Management System (Q & A)
10-21-2003, 05:13 PM
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AEM Engine Management System (Q & A)
For those of you who have any questions related to the AEM EMS I am offering our tuner Sean McElderry up for assistance to this forum. He is arguably the best AEM tuner in the world and can greatly assist you with any problems you might have.
We work in conjunction with AEM to promote their products and have installed AEM EMs's in our customers' Supra's / Civics / Eclipses / MR2's / S2000's / 3000GTs and RX7's for the past 2 years.
For those that are considering getting an AEM EMS for your S2000, let me list off some of the key selling points....
1) Auto-mapping... With this, you program in the target A:F based on engine rpm and load. We will typically program in around 11.5:1 under WOT situations, 14:1 on idle and 16:1 to 17:1 on cruise for economy reasons. Then you drive around and the cells in fuel map table will slowly change as you pass through them a few times until they get to the desired A:F ratio. We don't usually use this feature because it doesn't work as flawlessly as some of the other standalones out there, but it does work quite a bit better than it used to. I also don't like to do it because I don't like to take the chance of the computer doing something I don't want it to.
2) O2 Feedback.... We first tune the car with O2 feedback turned off. We do this by adjusting the values in the fuel map. We also use boost compensation (which I'll explain later) which makes this much easier. Once we're pretty close, we'll program the O2 feedback table with the target A:F ratios. Now when you're driving around, the computer is always using your fuel map but at the same it is doing on the fly adjustments to the fuel map based on your feedback settings towards your goal.
3) Boost Fuel Compensation.... We use boost compensation (especially on turbo'd and supercharged cars) to add or subtract from our fuel map. When using boost compensation, the fuel map ends up looking exactly like a torque curve with the peak fuel setting corresponding to the peak torque value. Then much of the fuel map has the same values all the way up and down (on the load axis). This makes it really easy to tune and allows for nearly perfect A:F ratios in all gears.
4) Knock and Timing.... Another thing the AEM does that is fantastic is it will allow you to program your own knock noise table based on engine rpm. There are a lot of things that make vibrations that the computer picks up as knock. Some might be real detonation, but a lot of the noise is simply shifting gears, a turbo wastegate opening, etc. etc. What we'll typically do is run some good gas like C-16 race fuel and leave the timing somewhat conservative. We'll then datalog the knock sensors. Once we have the raw knock values for the car, we'll modify the knock noise table to be right above these values. This tells the computer if you ever see a knock sensor voltage above this amount then it's probably detonation. Now we can program what to do if indeed we do see knock. #1 we pull out timing. You can program how much timing to pull out and how long and how fast to put it back in. You can also program a certain percentage of fuel to inject. Detonation can often be eliminated by injecting extra fuel. Once these are set, we can start advancing the timing to increase power until we do see some knock. then we can back it off a bit.
5) 2-step.... The AEM also has a built in 2-step where you can program it to not only pull spark, but pull timing as well. This 2-step can greatly increase your 60 fts. With boosted cars we've seen as much as 22psi built on the line.
6) Injector Duty Cycle.... One thing that we take very seriously is never running lean under WOT conditions. The AEM shows your injector duty cycle all the time. It allows you to make cylinder to cylinder fuel trim adjustments as well as overall fuel adjustments. We datalog the injector duty cycle and when you get past 80% injector duty cycle we typically recommend running larger injectors. On my personal car we went from 550cc injectors to 720cc to 850cc to 1000cc and we ended up hitting 85% injector duty cycle at 70psi of fuel pressure so now I have 1200cc injectors in it.
7) Boost Control.... If you are running turbos you'll never need another boost controller. You simply program in the w/g duty table and turn w/g feedback on and it will allow you to control boost perfectly through the AEM. You can also advance timing quite a bit in the turbo spool up area to reduce turbo lag.
8) Traction Control.... The newest version of the software now has traction control. It will pull out spark when traction is lost to maintain traction. If you do have turbos you can use speed based boost control to also prevent wheel spin.
Sean will be following this thread and will answer any questions that you may have with your EMS or any tuning related questions.
Take care,
Chris.
__________________
Chris Bergemann
http://www.horsepowerfreaks.com (parts)
http://www.torquefreaks.com (service)
(503) 256-5600
We work in conjunction with AEM to promote their products and have installed AEM EMs's in our customers' Supra's / Civics / Eclipses / MR2's / S2000's / 3000GTs and RX7's for the past 2 years.
For those that are considering getting an AEM EMS for your S2000, let me list off some of the key selling points....
1) Auto-mapping... With this, you program in the target A:F based on engine rpm and load. We will typically program in around 11.5:1 under WOT situations, 14:1 on idle and 16:1 to 17:1 on cruise for economy reasons. Then you drive around and the cells in fuel map table will slowly change as you pass through them a few times until they get to the desired A:F ratio. We don't usually use this feature because it doesn't work as flawlessly as some of the other standalones out there, but it does work quite a bit better than it used to. I also don't like to do it because I don't like to take the chance of the computer doing something I don't want it to.
2) O2 Feedback.... We first tune the car with O2 feedback turned off. We do this by adjusting the values in the fuel map. We also use boost compensation (which I'll explain later) which makes this much easier. Once we're pretty close, we'll program the O2 feedback table with the target A:F ratios. Now when you're driving around, the computer is always using your fuel map but at the same it is doing on the fly adjustments to the fuel map based on your feedback settings towards your goal.
3) Boost Fuel Compensation.... We use boost compensation (especially on turbo'd and supercharged cars) to add or subtract from our fuel map. When using boost compensation, the fuel map ends up looking exactly like a torque curve with the peak fuel setting corresponding to the peak torque value. Then much of the fuel map has the same values all the way up and down (on the load axis). This makes it really easy to tune and allows for nearly perfect A:F ratios in all gears.
4) Knock and Timing.... Another thing the AEM does that is fantastic is it will allow you to program your own knock noise table based on engine rpm. There are a lot of things that make vibrations that the computer picks up as knock. Some might be real detonation, but a lot of the noise is simply shifting gears, a turbo wastegate opening, etc. etc. What we'll typically do is run some good gas like C-16 race fuel and leave the timing somewhat conservative. We'll then datalog the knock sensors. Once we have the raw knock values for the car, we'll modify the knock noise table to be right above these values. This tells the computer if you ever see a knock sensor voltage above this amount then it's probably detonation. Now we can program what to do if indeed we do see knock. #1 we pull out timing. You can program how much timing to pull out and how long and how fast to put it back in. You can also program a certain percentage of fuel to inject. Detonation can often be eliminated by injecting extra fuel. Once these are set, we can start advancing the timing to increase power until we do see some knock. then we can back it off a bit.
5) 2-step.... The AEM also has a built in 2-step where you can program it to not only pull spark, but pull timing as well. This 2-step can greatly increase your 60 fts. With boosted cars we've seen as much as 22psi built on the line.
6) Injector Duty Cycle.... One thing that we take very seriously is never running lean under WOT conditions. The AEM shows your injector duty cycle all the time. It allows you to make cylinder to cylinder fuel trim adjustments as well as overall fuel adjustments. We datalog the injector duty cycle and when you get past 80% injector duty cycle we typically recommend running larger injectors. On my personal car we went from 550cc injectors to 720cc to 850cc to 1000cc and we ended up hitting 85% injector duty cycle at 70psi of fuel pressure so now I have 1200cc injectors in it.
7) Boost Control.... If you are running turbos you'll never need another boost controller. You simply program in the w/g duty table and turn w/g feedback on and it will allow you to control boost perfectly through the AEM. You can also advance timing quite a bit in the turbo spool up area to reduce turbo lag.
8) Traction Control.... The newest version of the software now has traction control. It will pull out spark when traction is lost to maintain traction. If you do have turbos you can use speed based boost control to also prevent wheel spin.
Sean will be following this thread and will answer any questions that you may have with your EMS or any tuning related questions.
Take care,
Chris.
__________________
Chris Bergemann
http://www.horsepowerfreaks.com (parts)
http://www.torquefreaks.com (service)
(503) 256-5600
10-21-2003, 05:19 PM
#2
Registered User
Chris,
Thank you for providing this service to the S2ki community. I will sticky this thread until you feel that is has been exhausted.
I want to also remind you that since you are not a site sponsor, you cannot solicit sales through this site for your company. If you'd like to become a site sponsor, please contact cthree of download the media kit at: https://www.s2ki.com/forums/mediakit.pdf
Once again, thank you for the offer of support to us here.
Thank you for providing this service to the S2ki community. I will sticky this thread until you feel that is has been exhausted.
I want to also remind you that since you are not a site sponsor, you cannot solicit sales through this site for your company. If you'd like to become a site sponsor, please contact cthree of download the media kit at: https://www.s2ki.com/forums/mediakit.pdf
Once again, thank you for the offer of support to us here.
10-21-2003, 05:23 PM
#3
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Just to start it off, I think what most people are concerned with is that the EMS is not plug and play as they are lead to believe with the advertising surrounding it.
I know there was trouble in the past with developing base maps for the S2000, how has this progressed over the years to make the unit more plug and play? Have these base maps been configured for the MY00/01 and MY02/03 since the stock ECU has been changed for these years.
For the current owners, how can they obtain these base maps for little or no cost to them from AEM?
I know there was trouble in the past with developing base maps for the S2000, how has this progressed over the years to make the unit more plug and play? Have these base maps been configured for the MY00/01 and MY02/03 since the stock ECU has been changed for these years.
For the current owners, how can they obtain these base maps for little or no cost to them from AEM?
10-22-2003, 08:59 AM
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3ngin33r1... thanks for the sticky. I will sponsor this forum. I'll get in touch with you about that.
The EMS can indeed be very close to plug-n-play these days. Version 1.03 is awesome and provides a ton of flexibility. When we sell our EMS kits, we deliver our base-maps with them. We have base maps for nearly every car and car configuration. We did a car yesterday that the customer said drives better now than it did when he bought it brand new. He said it drives smoother, rev's better, is perfect when you get in and out of the throttle. He road races, so this is very important to him.
The tricky part is getting the driveability issues worked out. That is where Sean comes into play. He's been doing this for a long time. He has created base maps for every car that will get the car nearly dead on. Then it's just a matter of very fine tuning.
I give the following analogy to people, "Let's say you have a bone stock S2000, and your buddy has a turbo-charged one with a bunch of other mods and he's running piggy-back's on his stock ECU to control fuel. Now you both swap the ECU's and nothing else. Will both cars run the same as they did before given the ECU's are for the same year and style of car? If you answer yes to that question, then you would have to agree that if Sean can tune the driveability issues nearly perfect in a number of S2000's, then his maps will probably work very well in your S2000. Now granted, everyone might have slightly different performance mods in their car such as a turbo or exhaust system, etc. but this is where the fine tuning comes into play.
Here's an S2000 we did yesterday.
Here's a shot of the engine. You can see the turbo tucked away on the left side.
Here's a before and after shot of our tuning. The 2nd result was a much smoother, much safer map at 7psi of boost. The A:F was tuned to 11.5:1.
Take care,
Chris.
The EMS can indeed be very close to plug-n-play these days. Version 1.03 is awesome and provides a ton of flexibility. When we sell our EMS kits, we deliver our base-maps with them. We have base maps for nearly every car and car configuration. We did a car yesterday that the customer said drives better now than it did when he bought it brand new. He said it drives smoother, rev's better, is perfect when you get in and out of the throttle. He road races, so this is very important to him.
The tricky part is getting the driveability issues worked out. That is where Sean comes into play. He's been doing this for a long time. He has created base maps for every car that will get the car nearly dead on. Then it's just a matter of very fine tuning.
I give the following analogy to people, "Let's say you have a bone stock S2000, and your buddy has a turbo-charged one with a bunch of other mods and he's running piggy-back's on his stock ECU to control fuel. Now you both swap the ECU's and nothing else. Will both cars run the same as they did before given the ECU's are for the same year and style of car? If you answer yes to that question, then you would have to agree that if Sean can tune the driveability issues nearly perfect in a number of S2000's, then his maps will probably work very well in your S2000. Now granted, everyone might have slightly different performance mods in their car such as a turbo or exhaust system, etc. but this is where the fine tuning comes into play.
Here's an S2000 we did yesterday.
Here's a shot of the engine. You can see the turbo tucked away on the left side.
Here's a before and after shot of our tuning. The 2nd result was a much smoother, much safer map at 7psi of boost. The A:F was tuned to 11.5:1.
Take care,
Chris.
10-22-2003, 10:07 AM
#5
Registered User
Thanks Chris for the detailed response. One other question (or maybe two or three).
The AEM is a mod I have been seriously considering after I went FI. I have seen that they also manufacture a WB02 device that connects to the EMS and from what it looks like, the sensor will replace the stock sensor and the EMS/WBO2 units are obviously smart enough to not throw a CEL when using it's own 0-5v sensor rather than the stock 0-1v.
So here's my question(s), what is the interaction between the EMS and the WBO2 unit? Obviously it's going to have a constant measurment of A/F, will the EMS autotune itself based on the WBO2 readings?
The AEM is a mod I have been seriously considering after I went FI. I have seen that they also manufacture a WB02 device that connects to the EMS and from what it looks like, the sensor will replace the stock sensor and the EMS/WBO2 units are obviously smart enough to not throw a CEL when using it's own 0-5v sensor rather than the stock 0-1v.
So here's my question(s), what is the interaction between the EMS and the WBO2 unit? Obviously it's going to have a constant measurment of A/F, will the EMS autotune itself based on the WBO2 readings?
10-22-2003, 10:21 AM
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3ngin33r1,
The EMS has what is known as 02 Feedback. You fill a table with your target A/F ratios. The table is RPM vs Load. When O2 Feedback is enabled the EMS fine tunes the supplied fuel, using the wideband as measurement to achieve the target A/F ratio. It is a terrific system for smoothing such changes as air temperature, barometric pressure, heat soak and other variables that would otherwise make an accurate A/F ratio impossible.
If you do not have a wideband then you can use your stock sensor (but not for initial tuning). The stock sensor will only supply accurate readings for an A/F of around 14:1 so it is only useful for while the car is idling or under low load. General consensus is that the stock ECU only uses feedback up to about 20% throttle position. With the wide band you are able target the A/F ration for whatever you want.
In practise I have found O2 feedback to very accurate. The rate at which it responds to change is fully configurable and it is easy to monitor how much fuel it is adding and when.
O2 Feedback can also be enabled under various conditions, such as the load is below X, the rpm is below Y and the coolant temperature is about Z etc.
As for the CEL... The EMS has complete control of the CEL. My CEL is used as an A/F ratio warning under boost. If the mixture gets too lean the CEL will illuminate which tells me instantly to 'back off'.
I have currently put 10,000 miles on my car since the EMS has been installed and I can safely say it has been the best thing I have done for the car. I know exactly what the engine is doing. I know exactly how it responds to knock. I know exactly why the EMS is doing what it does. Knowing provides a great deal of peace of mind.
Giles
The EMS has what is known as 02 Feedback. You fill a table with your target A/F ratios. The table is RPM vs Load. When O2 Feedback is enabled the EMS fine tunes the supplied fuel, using the wideband as measurement to achieve the target A/F ratio. It is a terrific system for smoothing such changes as air temperature, barometric pressure, heat soak and other variables that would otherwise make an accurate A/F ratio impossible.
If you do not have a wideband then you can use your stock sensor (but not for initial tuning). The stock sensor will only supply accurate readings for an A/F of around 14:1 so it is only useful for while the car is idling or under low load. General consensus is that the stock ECU only uses feedback up to about 20% throttle position. With the wide band you are able target the A/F ration for whatever you want.
In practise I have found O2 feedback to very accurate. The rate at which it responds to change is fully configurable and it is easy to monitor how much fuel it is adding and when.
O2 Feedback can also be enabled under various conditions, such as the load is below X, the rpm is below Y and the coolant temperature is about Z etc.
As for the CEL... The EMS has complete control of the CEL. My CEL is used as an A/F ratio warning under boost. If the mixture gets too lean the CEL will illuminate which tells me instantly to 'back off'.
I have currently put 10,000 miles on my car since the EMS has been installed and I can safely say it has been the best thing I have done for the car. I know exactly what the engine is doing. I know exactly how it responds to knock. I know exactly why the EMS is doing what it does. Knowing provides a great deal of peace of mind.
Giles
10-22-2003, 10:33 AM
#7
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Thanks Giles. So do you run the wideband sensor constantly or did you revert back to stock after tuning?
Also, is there any visual display for the EMS other than having your laptop plugged in?
Also, is there any visual display for the EMS other than having your laptop plugged in?
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10-22-2003, 10:44 AM
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I have a Techedge wide band that is permanantly connected about 6 inches after the turbo for optimal A/F ratios. The AEM wide band is also excelent. The EMS contains sensor tables for both models aswell as other such as FJO etc.
I have O2 feedback running pretty much all the time.
Other than a laptop you can use any PC device that supports windows and that has a serial port or in some cases a USB port with a suitable USB to serial convertor.
I went with a very neat and small onboard PC with a small LCD touch screen. This enables me to monitor everything as I'm driving the car as well as change settings on the fly. It cost a bit to do but I think it was well worth it as I have done a fair bit of tuning since Sean (TorqueFreaks) first tuned my car. Any changes that I have made Sean is sent so that he can incorporate them as he feels fit into the TorqueFreaks archive of calibrations. That way one can be sure that TorqueFreaks are at the top of their league. I will post a picture of my hardware setup.
I have O2 feedback running pretty much all the time.
Other than a laptop you can use any PC device that supports windows and that has a serial port or in some cases a USB port with a suitable USB to serial convertor.
I went with a very neat and small onboard PC with a small LCD touch screen. This enables me to monitor everything as I'm driving the car as well as change settings on the fly. It cost a bit to do but I think it was well worth it as I have done a fair bit of tuning since Sean (TorqueFreaks) first tuned my car. Any changes that I have made Sean is sent so that he can incorporate them as he feels fit into the TorqueFreaks archive of calibrations. That way one can be sure that TorqueFreaks are at the top of their league. I will post a picture of my hardware setup.
