Street Testing MSD’s Atomic EFI Conversion Kit

We recently installed MSD’s new Atomic EFI master kit on a sweet 1969 Nova daily driver owned by Corey Dotzler of Santa Barbara, California. In part one of our testing of the new EFI kit from MSD, we went through the installation of the kit from start to finish. As advertised, the Atomic EFI kit was an easy install with nothing out of the ordinary. For a complicated system like electronic fuel injection, making it a simple process is a positive.

Recapping the Installation

For a car that had to be trailered to the shop because the owner was afraid to drive it in southern California highway traffic, the ride back home was off the trailer and along the scenic Pacific coastline.

MSD ships the Atomic EFI Master Kit (Part #2900) with everything needed to complete the installation in most cases. If you are adding an external pressure regulator because you are plumbing in a return fuel line, you will need to source the regulator and fittings. There is an engine coolant temperature sensor that will need to be installed in the engine cooling system, so you will need to ensure that there is an available boss to install the coolant sensor.

MSD supplies a chart with point values assigned to critical conditions like daily operating temperatures, quality of fuel and fuel pump location. Based on the point totals for our setup, we came to the conclusion that our project Nova was on the boarder of needing a return line or relocation of the fuel pump.Our installation was straight forward and by the instructions. We chose to run the system without a return line because the car owner lives in a climate where the temperature is very mild and the engine is operated on 91-octane gasoline.

A baseline dyno before the installation and a final dyno run after told us what we needed to know about performance.

Going Returnless

The Atomic EFI handheld controller offers several different screens to monitor and adjust the system, one of those being a dashboard screen that allows the user to monitor critical engine measurements like A/F ratio, engine coolant temp and fuel pressure. We decided that running the system returnless while monitoring fuel pressure and A/F ratio would gives us a great indication on how the Nova would perform in this configuration.

Initial startup proved that the system would support a returnless design even under hard acceleration. The A/F and fuel pressure readings remained constant and it seemed that the returnless configuration would work well with our project car. We strapped the car down on our DynoJet chassis dyno and gave the car a full run to verify the A/F ratio and power measurements.

Corey Dotzler’s 1969 Nova

  • GM 454 HO crate engine (Part #12568774)
  • Cylinder Head: Cast iron, rectangular port
  • Valve Diameter: 2.19/1.88-inch intake/exhaust
  • Chamber Volume: 118cc
  • Camshaft: Hydraulic roller tappet
  • Lift: 0.510/0.540-inch intake/exhaust
  • Duration: 211 intake, 230 exhaust @ .050-inch tappet lift
  • Centerline: 112 ATDC intake, 112 BTDC exhaust
  • Rocker Arm Ratio: 1.7:1, stamped steel
  • GM Performance Parts aluminum dual plane manifold (Part #19131359)
  • 8.75:1 compression ratio
  • 3-inch-diameter exhaust system through Hedman ceramic-coated shorty headers and Flowmaster mufflers.
Driver Impressions

Prior to installing the Atomic EFI, Corey’s daily driver was a temperamental machine on the city streets. “It’s a little unruly in traffic, especially bumper to bumper traffic,” Corey told us. We verified what Corey told us when we pulled the beast onto the DynoJet chassis dyno for the baseline dyno run. The engine sputtered and hesitated throughout the run and had an inconsistent lopey idle. The large 850cfm carburetor was purchased second hand and bolted on top of the big block with no tuning or adjustments. This was not a well-tuned car.

Granted, the engine would have performed at a much higher level if tuned properly for the combination however, carburetor tuning is a slow dying art for the next generation of street hot rod enthusiasts which is where self learning EFI systems shine by handling the tuning internally within the system. It’s probable we would have seen similar results with other self-learning systems as well.

Our post installation dyno run positively showed what a properly tuned fuel system could do for the big block. “The idle is steady and consistent,” said Dotzler. “The acceleration seemed smooth and crisp,” he added.

On the Street

Right after the final dyno run we took the car around town to gauge the driveability of the crate engine equipped classic Nova. Power was not an issue. Corey was correct, the acceleration was crisp and very controllable. The unruly street behavior was replaced with good mannered aggression.

We took the car up and down the streets in various types of driving situations. Stop and go, long stretches of straight road and some twisties to check out the throttle control. Corey’s Nova exhibited a responsiveness to throttle input that made driving the classic a lot more exciting. For a car that had to be trailered to the shop because the owner was afraid to drive it in southern California highway traffic, the ride back home was off the trailer and along the scenic Pacific coastline.

Back Home

Once we were pleased with the installation and had collected all the data we needed to evaluate the Atomic EFI system, we sent Corey on his way to get some miles on the engine while the Atomic EFI performed it’s self learning function.

Two weeks later we gave Corey a call to see how the system was operating. “I couldn’t be more pleased with the EFI kit,” said Dotzler. “The only thing I changed was the camshaft setting because we had replaced the stock cam with a more aggressive one.” He confirmed that the performance in power and throttle control had continuously gotten better the more the car was driven. “At first there was an small issue with restarting the car when it was warm but that went away after a few days,” said Corey.

We sent Corey back home to put some miles on the system so that it could continue to self-learn and self-correct.

When asked about fuel mileage, Dotzler said, “It’s gotten better. It’s very noticeable when you don’t have to fill up as often.” This was expected, as with any fuel injection system that operates only at the time and amount that the engine demands at a given point.

Final Verdict

The Atomic EFI system took roughly 8-hours to install, even with our crew shooting video and photographs the entire time, and a quick 10-minutes to program the system by answering basic questions about the engine. The car fired right up and was road-worthy from the start. After 3-miles of self learning, the engine was running perfectly and we were able to Cory back on the road, heading for the coast.

The car owner was happy with his dream car after the conversion. Great performance and looks made this a win-win proposition.

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About the author

Bobby Kimbrough

Bobby grew up in the heart of Illinois, becoming an avid dirt track race fan which has developed into a life long passion. Taking a break from the Midwest dirt tracks to fight evil doers in the world, he completed a full 21 year career in the Marine Corps.
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