Project E46 M3: Part 6 – AEM Infinity Plug-and-Play EMS
Power with benefits
Our E46 BMW M3 is back. If you’ve missed any of the project you can visit the Project E46 M3 homepage. To recap, with bigger wheels, tires, a front-and-rear big brake kit and a healthy 323whp from the Epic Motorsports tune of the engine-back exhaust system, the car was as happy as a clam. The ECU hardware itself, however, suffered a broken pin due corrosion inside the 24-pin connector. Of all 80-plus pins it could have been, it turned out to be the one for the ECU relay and, thus, we had a temporarily dead ECU.
In anticipation of more power adders in the future, talks of installing a stand-alone ECU were already happening. But this untimely ECU mishap pushed us to move on this sooner. Enter Advance Engine Management Systems, otherwise known to the rest of performance industry as AEM.
Having run an AEM engine management system (EMS) with AEM gauges on one or more of my cars since 2003—including a 550whp E36 BMW M3 turbo (aka “Vader M3”) I had built for a different magazine years ago—I’ve always been confident in their products.
Looking through AEM’s website can be costly because there’s so much cool stuff to buy, including fail-safe and gauge-type methanol systems, digital and analog gauges, gauge-type boost controllers, sensors, all sorts of injector drivers and data loggers. Call me biased, but I’ve also honestly felt like I’ve always gotten more than I paid for, and their customer service is thick icing on the cake, too.
In 2012, AEM took the tuning world by storm with the release of the AEM Infinity EMS. The previous Series 1 and Series 2 systems are great, but the new Infinity EMS raises the bar to a whole other level.
From the start, it should be noted that the AEM Infinity EMS is to be used on cars that are used for off-road and racing purposes only, and never to be used on a public highway.
The AEM Infinity hardware features full weather proofing enclosure, motorports-grade connectors and printed circuit board technology. It also houses quad flat no-lead components (QFN) in its circuit board, which is an ideal choice for keeping things small, lightweight, and maintaining high electrical and thermal performance.
Gear heads may be wondering whether a stand-alone EMS is right for them. If you plan to keep your M3 lightly modified with, say, just an intake and exhaust tune on it, then a one-time ECU tune from a reputable source, like the one we tested from Epic Motorsports in Parts 1 and 3, works well.
If you plan to do several upgrades, however, you might be at a disadvantage. First, multiple upgrades can mean multiple tunes, and multiple tunes means multiple software flashes. The S54 computer has been known to lock tuners out after a couple dozen uploads, rendering the expensive BMW ECU useless. Some tuners claim to get past this, but it’s still a potential risk.
There’s also the need to pay considerable amounts of money for each flash, and most first-time tunes can range anywhere from $500-1000. You’re also extremely limited to the number of shops that can perform these types of custom tunes in-house, whereas there are several AEM tuners throughout the country that can tune your car on a dyno to maximize power, drivability and reliability, given your environmental and octane limitations. For years, I’ve sent my cars to Modified by KC here in the Kansas City area.
In the case of the E46 M3, it’s even better for AEM Infinity owners. Not only is the computer way faster than the factory S54 ECU, it incorporates CAN BUS—the “controller area network” standard that allows devices to communicate with each other within a vehicle. We'll show you more on this in the later pages, but think along the lines of launch modes, traction controls and map switching all done through the buttons on the factory steering wheel!