- Mon Sep 22, 2008 4:27 am
#70931
The AEM EMS is a standalone programmable engine management system that replaces your factory ECU.
What Does it Do?
With the EMS I was able to install an OBDII engine into my OBD1 chassis without changing the ECU harness, run an OBD1 VTEC distributor and injectors so I wouldn't have to rewire them, convert to distributor-less coil-on-plug using Honda motorcycle coils; have full adjustability of both VTEC crossover points, ignition timing, the fuel map, accel fueling and DFCO, injection phasing, purge control, idle and startup. I was able to set up an O2 Feedback target table to run extremely lean at cruising for mpg and rich under load for max power. I was able to set up wide-open-throttle shifting and a two stage rev limiter (for launching and over rev protection).
Resolution
The Fuel and Ignition tables have 17 load breakpoints and 21 RPM breakpoints. This is more than the factory ECU and it allows you to more closely follow the volumetric efficiency curve or you can have more cells for higher RPM and load than factory spec.
What Else Can it Do?
The EMS has the ability to control an extra set of injectors, nitrous, traction control, and a boost controller if I ever decide to go that route in the future. Controlling a two stage manifold ie the B18C is no problem. There are even user definable controls for anything the EMS engineers may not have dreamed up. You can also wire in a switch to control just about anything. The most common examples are to wire the clutch switch in for WOT shifting or wire in a nitrous button.
Plug N Play?
In most cases you unplug your stock ECU, plug in the EMS, upload a base map and start the car. A little bit of fighting with it to start and idle is common. Then you are free to tune away. Many people don't understand the word "base map". They think you can ask someone for a calibration from a similar setup, upload it, and you're all set. That is not the case. Someone else's map should be used just to get the car started and get you in the ballpark to save time tuning. But you always need to tune your car on a dyno, no matter what system you use.
Wiring was very minimal for me. If I had swapped in an OBD1 motor, then there would be almost no required wiring at all. I'm very comfortable with wiring but for people that find wiring VTEC difficult, they should leave this to a professional. I'm running an early AEM box that I've had for years on multiple cars. It's been replaced with a newer model (30-1040). My box (30-1000) requires that you de-pin the redundant ignition wire. I wired up the second VTEC solenoid and knock sensor and had a professional set them up in the software.
Honda Distributors
Honda distributors suck. They are the least reliable part on the entire car. The problem is inherent to the design. You have a cam/crank sensor that puts out a very weak voltage in the same housing as the coil and ignitor which output a very powerful spark voltage. The high voltage tends to interfere with the weak signal. You also have the problem of the distributor shaft wobbling and oil leaking past the seal. What most people don't know is that Honda built a work-around into the stock ECU so that it will tolerate a bad cam/crank signal. Your car runs fine, then you install a standalone and it wont sync up. Aftermarket distributors are even worse. The best thing you can do is replace your distributor with an AEM EPM and convert to distributor-less ignition. The EPM gives you a much stronger cam signal reliable well into high RPM where the stock signal lags behind and breaks up.
Price
$1800 for the EMS and $250 for the Gauge Type wideband is about what people typically spend on bodykits and JDM conversions. For what you get (and a standalone is the ONLY way to get these particular features), $1800 - $2100 is a bargain. Dyno tuning typically costs $100 an hour. Starting with the included base maps a good tuner should be able to tune most setups within an hour.
Where to Buy
Even if you have to pay more, do not buy an EMS on ebay. Buy it from the tuner that will be tuning it for you.
Warranty
AEM has a limited time warranty but I never had a problem with it within that time period. I did have the coil drivers go out years later and it only cost me $50 for them to fix it. They got it fixed and back to me in less than a week.
Gains
On my setup with the stock ECU I could expect close to 110 hp at the wheels. With the EMS and a quick tune I achieved 119hp. These numbers only indicate the peak gain. If I had the stock P2J ECU I could have got a good baseline to compare the entire power curve. I could have got even better power if I didn't start having distributor problems. The torque gain over stock I'm sure what have been even more impressive but I just don't have any solid numbers.
Using a wideband O2 sensor and careful/precise tuning of the fuel and ignition, I'm able to run as lean as 18:1 on my lean burn motor during cruise and even light throttle acceleration. I'm running relatively lean with aggressive timing throughout most of the driving range and the high load range was professionally dyno tuned at the ragged edge of the line between power and engine safety. At 2000 RPM and below the fuel mixture is tuned for stoichiometric in order to pass smog, get good fuel economy and a stable idle.
Software
AEM has gone through many versions of it's AEMPro software that is installed on your laptop so that you can tune the EMS. You can tune it live with the engine running or you can make changes on the computer and then upload the new calibration. AEMPro is easy to navigate and pretty self-explanatory if you've ever tuned before. Many amateurs who call themselves tuners can feel overwhelmed, but an experienced tuner or anyone who's studied fuel injection will appreciate that having a lot of features necessitates "complexity".
I had my car tuned professionally but I've done nearly all the drive-ability tuning myself. I've perfected idle and start-up, got it to pass smog, improved the fuel economy, etc. It's been a great learning experience although many times I've been frustrated by the lack of documentation (some options have no clear definitions and may be for applications that don't even apply, others have explanations but they're ambiguous). AEM offers factory training but it's only available for people that work in the industry. They don't teach how to tune (like EFI101.com does) but rather they teach established tuners the specifics of their system.
AEMTuner
AEMTuner replaces AEMPro and has worked fine for me in beta form. Essentially they reworked the interface starting from scratch.
Fully Customizable Interface
Both AEMPro and AEMTuner beta feature a fully customizable interface. You can create your own shortcuts that immediately bring up all the parameters and windows exactly how you save them. You can edit out items in the menu that don't apply to you. For instace, I edited out boost, automatic trans, and nitrous among others because I wont be using them any time soon. Getting them out of the way reduces clutter on the screen and makes it easier to get to the menus I use every time.
Logging
AEMLog allows you to view various parameters (sensor readings) over time in graph form. It's essentially anything you could ask for in a logging software and is slated to improve even further with upcoming updates.
Software / Firmware Updates
It's really cool that you can download the software and firmware updates for free and even the fact that the EMS is update-able at all. Hondata, Haltech, and even Motec all sell more expensive units but you'll notice that there's just one EMS per application and it has everything.
Scale 1-10
On a scale of 1-10, 1 being stock, 10 being Motec, the AEM would be right about 9. In some ways it's better than Motec, ie it's Plug N Play, less expensive, and the software contains a lot of Honda specific terminology. I'd put Hondata at like a 4, FAST and Haltech about a 5. Chipped ECU would be 2 maybe maybe a -1 depending on what crap was running on it (Crome).
The reason I don't give it a 10 is because the documentation isn't complete and the software is good but still has room to improve. There are also some minor bugs/flaws in both the software and firmware.
Bottom line is that if you are really serious about having a fast Honda, you have an AEM EMS. Nothing else on the market can compare to it in terms of quality and in the amount of features and expandability it offers.
The AEM EMS is a standalone programmable engine management system that replaces your factory ECU.
What Does it Do?
With the EMS I was able to install an OBDII engine into my OBD1 chassis without changing the ECU harness, run an OBD1 VTEC distributor and injectors so I wouldn't have to rewire them, convert to distributor-less coil-on-plug using Honda motorcycle coils; have full adjustability of both VTEC crossover points, ignition timing, the fuel map, accel fueling and DFCO, injection phasing, purge control, idle and startup. I was able to set up an O2 Feedback target table to run extremely lean at cruising for mpg and rich under load for max power. I was able to set up wide-open-throttle shifting and a two stage rev limiter (for launching and over rev protection).
Resolution
The Fuel and Ignition tables have 17 load breakpoints and 21 RPM breakpoints. This is more than the factory ECU and it allows you to more closely follow the volumetric efficiency curve or you can have more cells for higher RPM and load than factory spec.
What Else Can it Do?
The EMS has the ability to control an extra set of injectors, nitrous, traction control, and a boost controller if I ever decide to go that route in the future. Controlling a two stage manifold ie the B18C is no problem. There are even user definable controls for anything the EMS engineers may not have dreamed up. You can also wire in a switch to control just about anything. The most common examples are to wire the clutch switch in for WOT shifting or wire in a nitrous button.
Plug N Play?
In most cases you unplug your stock ECU, plug in the EMS, upload a base map and start the car. A little bit of fighting with it to start and idle is common. Then you are free to tune away. Many people don't understand the word "base map". They think you can ask someone for a calibration from a similar setup, upload it, and you're all set. That is not the case. Someone else's map should be used just to get the car started and get you in the ballpark to save time tuning. But you always need to tune your car on a dyno, no matter what system you use.
Wiring was very minimal for me. If I had swapped in an OBD1 motor, then there would be almost no required wiring at all. I'm very comfortable with wiring but for people that find wiring VTEC difficult, they should leave this to a professional. I'm running an early AEM box that I've had for years on multiple cars. It's been replaced with a newer model (30-1040). My box (30-1000) requires that you de-pin the redundant ignition wire. I wired up the second VTEC solenoid and knock sensor and had a professional set them up in the software.
Honda Distributors
Honda distributors suck. They are the least reliable part on the entire car. The problem is inherent to the design. You have a cam/crank sensor that puts out a very weak voltage in the same housing as the coil and ignitor which output a very powerful spark voltage. The high voltage tends to interfere with the weak signal. You also have the problem of the distributor shaft wobbling and oil leaking past the seal. What most people don't know is that Honda built a work-around into the stock ECU so that it will tolerate a bad cam/crank signal. Your car runs fine, then you install a standalone and it wont sync up. Aftermarket distributors are even worse. The best thing you can do is replace your distributor with an AEM EPM and convert to distributor-less ignition. The EPM gives you a much stronger cam signal reliable well into high RPM where the stock signal lags behind and breaks up.
Price
$1800 for the EMS and $250 for the Gauge Type wideband is about what people typically spend on bodykits and JDM conversions. For what you get (and a standalone is the ONLY way to get these particular features), $1800 - $2100 is a bargain. Dyno tuning typically costs $100 an hour. Starting with the included base maps a good tuner should be able to tune most setups within an hour.
Where to Buy
Even if you have to pay more, do not buy an EMS on ebay. Buy it from the tuner that will be tuning it for you.
Warranty
AEM has a limited time warranty but I never had a problem with it within that time period. I did have the coil drivers go out years later and it only cost me $50 for them to fix it. They got it fixed and back to me in less than a week.
Gains
On my setup with the stock ECU I could expect close to 110 hp at the wheels. With the EMS and a quick tune I achieved 119hp. These numbers only indicate the peak gain. If I had the stock P2J ECU I could have got a good baseline to compare the entire power curve. I could have got even better power if I didn't start having distributor problems. The torque gain over stock I'm sure what have been even more impressive but I just don't have any solid numbers.
Using a wideband O2 sensor and careful/precise tuning of the fuel and ignition, I'm able to run as lean as 18:1 on my lean burn motor during cruise and even light throttle acceleration. I'm running relatively lean with aggressive timing throughout most of the driving range and the high load range was professionally dyno tuned at the ragged edge of the line between power and engine safety. At 2000 RPM and below the fuel mixture is tuned for stoichiometric in order to pass smog, get good fuel economy and a stable idle.
Software
AEM has gone through many versions of it's AEMPro software that is installed on your laptop so that you can tune the EMS. You can tune it live with the engine running or you can make changes on the computer and then upload the new calibration. AEMPro is easy to navigate and pretty self-explanatory if you've ever tuned before. Many amateurs who call themselves tuners can feel overwhelmed, but an experienced tuner or anyone who's studied fuel injection will appreciate that having a lot of features necessitates "complexity".
I had my car tuned professionally but I've done nearly all the drive-ability tuning myself. I've perfected idle and start-up, got it to pass smog, improved the fuel economy, etc. It's been a great learning experience although many times I've been frustrated by the lack of documentation (some options have no clear definitions and may be for applications that don't even apply, others have explanations but they're ambiguous). AEM offers factory training but it's only available for people that work in the industry. They don't teach how to tune (like EFI101.com does) but rather they teach established tuners the specifics of their system.
AEMTuner
AEMTuner replaces AEMPro and has worked fine for me in beta form. Essentially they reworked the interface starting from scratch.
Fully Customizable Interface
Both AEMPro and AEMTuner beta feature a fully customizable interface. You can create your own shortcuts that immediately bring up all the parameters and windows exactly how you save them. You can edit out items in the menu that don't apply to you. For instace, I edited out boost, automatic trans, and nitrous among others because I wont be using them any time soon. Getting them out of the way reduces clutter on the screen and makes it easier to get to the menus I use every time.
Logging
AEMLog allows you to view various parameters (sensor readings) over time in graph form. It's essentially anything you could ask for in a logging software and is slated to improve even further with upcoming updates.
Software / Firmware Updates
It's really cool that you can download the software and firmware updates for free and even the fact that the EMS is update-able at all. Hondata, Haltech, and even Motec all sell more expensive units but you'll notice that there's just one EMS per application and it has everything.
Scale 1-10
On a scale of 1-10, 1 being stock, 10 being Motec, the AEM would be right about 9. In some ways it's better than Motec, ie it's Plug N Play, less expensive, and the software contains a lot of Honda specific terminology. I'd put Hondata at like a 4, FAST and Haltech about a 5. Chipped ECU would be 2 maybe maybe a -1 depending on what crap was running on it (Crome).
The reason I don't give it a 10 is because the documentation isn't complete and the software is good but still has room to improve. There are also some minor bugs/flaws in both the software and firmware.
Bottom line is that if you are really serious about having a fast Honda, you have an AEM EMS. Nothing else on the market can compare to it in terms of quality and in the amount of features and expandability it offers.