A little more than a decade ago, it seemed as if electronic fuel injection (EFI) would completely reshape the auto racing landscape and replace carburetors in almost all top-tier classes.

NASCAR Cup cars made the switch in 2012, trading a Holley HP series carb for a Holley EFI throttle body that sits atop a conventional-style single-plane intake manifold modified for fuel injectors. The ARCA series introduced a new engine package in 2015, developed by Ilmor, which included an entire Holley EFI system. Three years later, the NASCAR Truck series adopted the same package. NHRA Pro Stock mandated a Holley-based EFI in 2016 after more than 45 years of dual four-barrel setups.

A surge of aftermarket EFI development followed those examples. It wasn't that long ago that only a handful of companies, like Holley, BigStuff3, FAST, Electromotive, MoTeC, Haltech, and a couple of others in the UK and Australia, offered ECUs, wiring harnesses, and other EFI equipment to amateur and pro racers on a wide scale. Today, numerous companies are in the EFI market, designing not only highly sophisticated hardware and software, but also entry-level, self-tuning products for those on a budget.

These observations beg the question: Has the shift to EFI hit a ceiling? The debate over whether there's a performance advantage has pretty much been sorted out—and the answer depends on the application and the rules.

Finding The Advantage

"One of the struggles is always cost," observed Ben Strader of EFI University, Lake Havasu City, Arizona. "You look at circle track, ASCS, 360 or 305 sprints, RaceSaver guys—they're happy. They're not looking for a solution to end any problem. So it's really hard to sell those guys on EFI. I think the growth in the marketplace is where somebody's looking for an advantage. That tends to be drag racing, where you follow the weather and extract more power through tuning. Or road racing, where you're looking for efficiency and fuel economy."

Cost plays a significant role in any technical changes considered by a sanctioning body, especially when evaluating the benefit to the racer.

"With the restrictions in the rules and many series adopting crate engines, there isn't a huge performance advantage—at least not enough to justify the expense if they have a good carburetor and fuel system and are running up front every week," said Graham Fordyce of Holley, Bowling Green, Kentucky.

The sanctioning body itself must also balance progress with scarce human resources, including relying on older volunteers with 20 to 40 years of experience inspecting carburetors, but who have no EFI background.

"The majority of sanctioning bodies have a rule that prohibits data logging and any form of traction control. Again, without trained officials, how can you enforce a rule when you can't detect it?" asked Fordyce.

Cost factors multiply when considering the expense of teams adding a laptop computer, electric fuel pumps, and safeguards to shut off the pump in the event of an accident.

"We have provisions for this with the Holley ECUs, but the officials need to know how to test this," added Fordyce. "With a carburetor and a mechanical pump, the fuel flow stops as soon as the engine stalls. Sanctioning bodies also believe that if they allow EFI, the teams will need to hire an engineer to get all the benefits of EFI, which will greatly increase the cost of racing."

Tailored Solutions

Since Holley has been a carburetor powerhouse from the early 1900s as well as a leading EFI innovator more recently, the company can serve both interests.

"Our motorsports group works with the teams and sanctioning bodies to ensure they have the best products for their situation. Plus, we provide trackside support at as many events as we can," said Fordyce.

Over at NHRA, Holley products are mandated in Pro Stock and Factory X. Both use the Holley HP ECU with a spec rev limiter hard-coded in the firmware set to 10,500 rpm in Pro Stock and 10,200 rpm in Factory X.

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