If you’ve been modifying Japanese imports for a more than a few years, chances are you’ve installed an AEM cold-air intake on a car or two. These cleverly engineered long-tube intake systems have stood the test of time, proving their effectiveness thousands of times on the dyno and turning more than a few heads thanks to their unique induction noise. But as the name suggests (AEM stands for Advanced Engine Management), this Hawthorne, California-based manufacturer has a lot more going on than just “filters on a stick.”
AEM actually started out as a tuning facility, so engine management has always been in its blood. Back in the day, AEM was the R&D department for Redline/Weber, becoming a stand-alone facility in 1987. A decade later it became a full-time manufacturer, re-entering the electronics/engine management world in 2003 with its now-famous Series 1 EMS. The Series 1 EMS was so impressive that it won the Primedia Technology Award in 2004 as the first EMS to plug into a factory harness. That year also marked the introduction of its first-generation wide-band controllers, and in 2005, AEM introduced the first wide-band controller gauge on the market.
Clearly the company has been a leader and an innovator in the performance electronics industry, and better still is the fact that it brought these products to the masses thanks to pricing that didn’t require organ donation. That’s really the beauty of AEM’s approach to performance electronics and engine management: Regular guys like you and me who before could only dream of owning the electronic unobtanium we’d see on professional race cars suddenly found it within reach. And now, with AEM’s new Infinity EMS, the bar has been raised even higher in the world of affordable engine management thanks to a whole host of new and innovative features and options that not only make ECU tuning easier and more accurate but also make it safer and more reliable.
To give you a quick idea of how advanced the Infinity is compared with the previous-generation unit (Series 2 EMS), check out the chart for a side-by-side comparo. It’s pretty telling stuff, with highlights than include a 32-bit 200-mhz CPU core capable of executing 400 million instructors per second, making it 20 times faster than the previous-gen ECM. It also has far more sophisticated data logging, traction control, and knock sensing capabilities that we’ll get into later, along with a super robust case that makes it suitable for engine bay mounting.
But what really sets the Infinity EMS apart is, according to AEM Marketing and PR Director Lawson Mollica, its ability to do airflow model-based calculations. “The real benefit of an airflow model, and therefore VE- [volumetric efficiency] based tuning, is that the numbers make inherent sense to the tuner without any additional knowledge required. In older injector pulse-width-style systems, the main tuning tables work in units of time, or milliseconds of injector-on time. These numbers are meaningless on their own, and without injector flow information, the number of injectors, the size of the engine, and so on, the tuner can’t say what the table actually means. Is 6 ms of fuel rich? Is it lean? You can’t know without more information. With VE model-based tuning, the general airflow characteristics of the engine are tuned, not the specifics; you leave that up to the model. Now you simply have to tell the system how good the engine breathes at different operating points. Even if you are off in your initial estimates, you are still going to be pretty close, and it’s easy to make the initial estimates because the numbers make sense. You let the model take care of the effects of temps, pressures, gas constants, engine displacement, and other factors. What this means, essentially, is that you can be way off your optimum VE number and the car will still run because all these other variables are in play.”
This change to airflow model-based calculations based on the engine’s volumetric efficiency not only makes tuning far more intuitive, but when combined with some of the Infinity’s other features, it also makes it a far safer stand-alone system to tune with. One such feature is the Internal Simulator, which allows the user to simulate input channels to the Infinity EMS. As Lawson explained, “If you know a given engine combination should make a certain amount of horsepower and you have a certain size injector, with experience, you will know at WOT what your injector duty cycle value will be. You can plug all that data into your VE table and then the simulator will show you what the ECU will do under those circumstances, without actually having to run the engine, which means you can test changes to the VE table without putting the engine at risk.”