AEM Series 2 ECM

Plugging and Playing with AEM's Series 2 ECM and B-Series Coil on Plug Kit

By Joe Popovits

If you're up to speed on the Project Civic EJ series, then you're familiar with its rather unique engine built by MotoIQ editor Chuck Johnson.  In short, Project Civic EJ's compression ratio has been increased through a set of JE Pistons and its rod ratio improved through the use of K1 Technologies connecting rods originally intended for a Nissan QR25DE.  A gambit of additional modifications were also performed to the cylinder head as well as the intake and exhaust system.  If you're not up to speed on the build, be sure to get up to caught up here at the Project Honda Civic EJ's summary page.


Project Honda Civic EJ at Buttonwillow Raceway

It's clear that Project Honda Civic EJ's B18C1 has been significantly re-engineered to quickly power the popular Honda chassis around the track.  Now, if only we had something awesome enough to control this mechanical masterpiece… Oh wait, we totally do!  The AEM Series 2 plug and play ECM.


OEM 1997 B18C1 ECUIt was apparent that our built B18C1 had outgrown the factory Honda engine control unit (ECU).

The factory Honda ECU simply was not capable of adjusting its tune enough to run the engine correctly.  Typically in cars of this generation, the factory ECU will have one main fuel map which will trim approximately 5% fuel in closed loop.  During closed loop, the ECU looks at the O2 sensor for feedback of the air fuel mixture and as a result, adds or subtracts small amounts of fuel.  This trimming of fuel is continuously occurring during the engine's operation in closed loop.

On the flipside, during wide open throttle (WOT) the ECU moves to open loop and ignores any trims to the main fuel map. One of the reasons you can get away with making a bit more power with a stock ECU is because the default WOT map is conservatively tuned with a slightly rich mixture.


b18c1 honda acura

When modifying an engine, you essentially increase its efficiency as an air pump.  However, two more ingredients are needed to complement that efficiency and make more power.  These two ingredients are additional fuel and proper ignition timing.

Since the factory ECU can only make small adjustments in fuel and timing, it often becomes a menacing roadblock for many people which ultimately discourages further engine modification.  Chances are if you're reading this, you're like us and wouldn't stop there.  Fortunately, we have AEM to help get us over the engine management hurdle.


AEM Series 2 ECMIf our long rod, high compression engine is the heart of Project Civic EJ, then the ECU is certainly the brain.  With the plug and play nature of AEM Series 2 EMS, the decision was a no-brainer.

Many piggy back type options exist for supplying the engine with more fuel while keeping the stock ECU, but none of these devices compare with the  Series 2 EMS's ability to fully control the engine. In all fairness, these alternatives may be just the ticket for your application; they're cheap, readily available, and easy to install and remove.

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Dusty Duster
Dusty Dusterlink
Wednesday, January 29, 2014 7:41 AM
That coil-on-plug conversion kit looks pretty cool!
Wednesday, January 29, 2014 8:04 AM
I am going to take a conservative shot and say 215 whp. But I will probably be way off on it. Can't wait to see the dyno numbers.
Wednesday, January 29, 2014 12:31 PM
But does it have knock control?
Wednesday, January 29, 2014 1:43 PM
It's a Honduh, so I'm going to say 300hp @ 9k RPM and a lowly 12 ft/lbs of torque ;-)
Actually I'm very curious to see what this thing does.
Wednesday, January 29, 2014 2:00 PM
Hmm, 215 to the ground from a B18 is pretty good for 11.5:1 compression. I think we may see closer to 205 to the wheels with a better torque curve due to the rod ratio.
Wednesday, January 29, 2014 4:16 PM
I recognize the standard capacitive discharge CBR coils (with the valve cover grommets removed) and a Bosch Audi/VW coil driver. Can you buy the crank trigger separately?
Wednesday, January 29, 2014 7:43 PM
215whp with gobs of mid range torque and awesome reliability! :D

I think it's pretty sad that most honda track enthusiasts (like me) usually have a spare distributor in their toolbox...
Chuck Johnson
Chuck Johnsonlink
Wednesday, January 29, 2014 9:35 PM
There are some interesting guesses in here regarding HP. Any guesses on how many seconds were shaved off the lap times at BW config 13?
Chuck Johnson
Chuck Johnsonlink
Wednesday, January 29, 2014 9:38 PM
@pizzamaniac- yes to the knock control question

@fabrick8- not sure if you can buy just the CAS from AEM. You'd have to call them.
Thursday, January 30, 2014 4:20 AM
I am guessing 220hp.

Why no mention of the option of OBD1 ECU conversion?
Scott Helmer
Scott Helmerlink
Thursday, January 30, 2014 9:09 PM
@fabrick8 - Yes, yes you can, they just have a different name for it on their website (EPM - Engine Position Module as opposed to CAS).

Hmmm... I think I'm probably in the 215-220whp camp with everybody else. Can't wait to see the results!
Wednesday, February 05, 2014 9:42 PM
With the OBD1 ECU, tuned with Neptune, flat foot shifting is tunable. On a Dynapack, im gunna geuss 218hp, 155-160ish ft lbs. Needs a better intake manifold.
who needs brakes
who needs brakeslink
Wednesday, August 12, 2015 10:36 AM
Sorry to bump, but I just read this and cannot find the next segment. What the project scrapped or just the ECU?
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