A few years ago MSD rolled out its original Atomic EFI system for LS enthusiasts at SEMA, changing the way many of us viewed and used fuel injection on our LS engine swaps. At the 2015 SEMA Show, MSD is at it again, this time with its new Atomic Stage 1 EFI for LS engines.

There are a handful of primary hurdles to overcome when installing an aftermarket EFI system. The first is the wiring harness. Adding sensors, splicing wires, assembling connectors, and routing a harness can all seem like a daunting task. The second hurdle is tuning. Having not only a compatible laptop, but the skill and knowledge to get the car started creates another major hurdle for many enthusiasts. Lastly is the cost. With a price tag that is often much higher than a good carburetor and intake manifold, or a repurposed OEM harness, an aftermarket EFI can appear to be an expensive alternative.

The Atomic Stage 1 is designed to change all of this. “This is a standalone that will perform on any LS engine with a wiring harness, and is non-PC programmable. It will do the same as the atomic series. It is designed for the novice, and will get any LS engine running for under $1,000,” says MSD’s Joe Pando.

There is an optional drive-by-wire harness for $85 as a plug-in harness upgrade. Pando says this system will work with any engine in the LS family. Designed for the DIY enthusiast the Atomic Stage 1 will also support boosted applications.

The system is non-PC programmable and works via a handheld programmer similar to other versions of Atomic EFI. It is not without some limitations, however. “Because it is self-tuning, it does have some cam-based limitations. Camshafts larger than 240 duration at .050 are going to be limited because the MAP sensor can’t tune the system when it sees erratic pulses caused by this type of camshaft,” Pando says.

Billet Throttle Body

 

MSD also displayed fits for the 93 mm throttle body for LS applications. This all billet-constructed throttle body is cable actuated instead of drive-by wire. “This throttle body is unique since it’s modeled after the OEM design,” Pando says. “It has a parabolic shape at the inlet that meters the airflow correctly on a street car, and gives better drivability, so that when you crack the throttle open you don’t get too much air all at once.”

The Billet 93 mm throttle body utilizes the OEM IAC and TPS sensors, and fits just about any LS specific intake manifold on the market.

LT1 Intake

The aftermarket has been quick to latch onto GM’s new LT1 engine, recognizing it as the future of GM-based performance. At SEMA, GM was showing off its new Atomic intake for the LT1 engine. “This design is based on what we learned for the LS1, LS2, LS6, and LS7 engines. This intake on a stock 2015 Corvette picks up 17 hp on the dyno,” Pando says. Like the LS-designed intakes, this one is also constructed of lightweight composite materials and features the MSD Atomic logos prominently.

The LT1 introduced direct injection (DI) to the GM V8 family for the first time. DI has been the major hurdle in making additional power once the fuel system reaches its limits. This new intake can help resolve that issue since, as Pando points out, it has ports for additional injectors to make more power. “If you have an ECU that will control additional injectors you can add more fuel to make more power,” Pando says.

Getting more fuel in to the LT1 is key when making big power with these engines. With more airflow potential from the new atomic intake, and the provisions for adding additional injectors, MSD is making the option to gain increased power that much easier.