In the spectacle that is professional wrestling, signature moves come and go, but one classic has stood the test of time: the Atomic Elbow. What differentiates the Atomic version from your run-of-the-mill elbow and makes it so effective? One word: intensity. MSD's Atomic EFI is every bit as effective and might be just as devastating to the competition, but we are getting ahead of ourselves. Let's start with the fact that we were more than a little skeptical about yet another self-learning, self-tuning EFI system—especially one that promised to work equally well on normally aspirated and (of all things) power-adder applications. Seriously, can you imagine allowing a computer to tune your turbo LS motor all by itself?
Let's take a look at the promises made by the new LS-specific Atomic EFI system (other universal systems are available for conventional applications). First off, don't confuse the promotion of a wired-less system with a wireless system. The wired-less system promised and delivered a reduction in the amount of unsightly wiring. Truth be told, wiring harnesses for both factory and stand-alone EFI systems tend to border on the excessive, making it difficult to create a sanitary engine compartment. Builders have gone to great lengths to conceal all the wiring, but MSD's system has done it for you by hiding the majority of the system under trick, billet aluminum fuel rails that also incorporate the ECU circuitry. In one fell swoop, the system has eliminated the lengthy wiring harness usually associated with remote mounting the ECU(s), replacing it with a single cord run to a hand-held controller. Our one complaint is that we'd like to see an extension cable offered for in-car (or dyno) access to the controller, but the MSD Atomic EFI system gets high marks for both the visual statement and ease of installation with good instructions and a clearly labeled harness.
It looked the part, but now it was time to see if this EFI system was indeed ready to play with the big boys. Prior to installing the Atomic EFI, we tuned this LS3 we borrowed from Gandrud Chevrolet with a stand-alone system to establish a baseline. To illustrate the effectiveness of MSD's system, we decided to start off with something easy, then drop in an Atomic Elbow of our own.
First up was the stock LS3 crate motor. In truth, setting up the system was as easy as the installation. Once we had power, we simply scrolled through the easy-to-use menu of available options. For our application, all we had to do was select LS3 from the available options of LS motors, and the Atomic EFI did the rest by selecting the necessary injectors, map, and 58X trigger wheel. You can select custom options like cam profiles, but our stock engine required only that we click LS3. Fuel was supplied to the billet rail by an Aeromotive fuel pump and regulator. According to MSD, the rails are capable of supporting more than 1,000 hp.
Once programmed, the LS3 fired up at the first push of the starter button and immediately settled into an idle with an optimized air/fuel mixture. The menu on the controller allowed us to program a desired air/fuel mixture at idle, part throttle, and WOT. We selected a 12.8:1 air/fuel mixture at WOT and proceeded to make a few pulls. All we can say is wow, because the Atomic EFI system performed as promised. The system maintained the desired air/fuel mixture at all throttle angles and loads. According to MSD engineers, GM's stock timing tables were loaded into the system, meaning the settings are conservative, rather than set for maximum power. That's no problem, because not only did the controller menu allow us to add ignition timing but also functioned as a data-logging system, which can also be displayed digitally. It's hard to believe, but once we had the LS3 running with 30 degrees of total timing, to match the ignition map used with the stand-alone management system, MSD's Atomic EFI matched the power curve of the programmable EFI system.