When the folks at Holley Performance set out to design the original Dominator EFI system, they did so with the specific intent of developing something that was incredibly capable, yet also accessible; a system that embodied the concept of “EFI for all.”

“There were other high-end options out there at the time, but the problem was that they seemed like they were designed for engineers rather than racers and enthusiasts,” explains Ryan Witte of Holley Performance. “And those are two different types of people. Your typical enthusiasts just want to go fast and have fun with their car. They don’t want to spend all of their time learning the principles of fuel injection just to make it work. So our goal with the Dominator system was to reduce cost, increase features, and make those features easy to use.”

As a result, when the Dominator EFI system came to market, it had the distinction of being the first to have drive-by-wire and transmission control included in its base price rather than as an optional add-on. And by Witte’s estimation, it was also the first system to be truly plug-and-play with the LS engine platform.

“There were competitors that offered similar features, but they had massive upgrade costs to get the same functionality as the Dominator.”

And that approach provided the Dominator system with the flexibility to be adapted to a wide variety of applications and use cases. “It was right around the time when Drag Week started, and without realizing it, Holley Performance had created the perfect solution for a build like that. Drag Week builds are all over the map, and they have a wide variety of needs, so this was purpose-built for the job.”

Devin Vanderhoof of HCR Innovations agrees. The Pelzer, South Carolina-based tuning and wiring specialist focuses on the sort of finishing work that takes street machines and race cars from “running” to running right, and Vanderhoof notes that there’s a big difference between the two when it comes to these types of applications.

“It doesn’t take much to make cars run, but it does take a lot to make them do all the other stuff correctly, and that’s where the Dominator shines. And drag-and-drive cars are kind of the ultimate test of that. People make this assumption that street cars are less complex than dedicated race cars, but it’s actually the opposite in this case. These cars have to not only perform at the track, they also have to work on the street, and that requires features that can be adapted to a much wider range of situations and scenarios. Really, at the end of the day, the Dominator is for anyone who wants to be able to control everything in their car.”

Going Above and Beyond

The aforementioned features, like drive-by-wire control and transmission control, as well as configurable IO and plug-and-play compatibility with the larger Holley Performance ecosystem made Dominator EFI a compelling option right out of the gate. But it’s the system’s adaptability, and its steady evolution through software updates that have kept it at the forefront of the EFI realm over the years.

“One of the Dominator’s biggest advantages is the number of inputs and outputs it offers, and the fact that they’re user-customizable, so they can do whatever you need them to do,” says Witte. “We have all this expansion in there, so people can do what they want. We also try to look at what people are doing with these systems and then add that feature to the ECU, so they don’t have to use their customized IO port to do it. Power management is a big part of that: We have a lot of packaged ways to manage power in the ECU, but you can’t anticipate them all – people always want to try a new way of managing power. And that’s where having configurable IO, and configurable tables for people who need that, delivers that flexibility.”

Vanderhoof says that people tend to focus on the input/output count when cross-shopping EFI systems, but that doesn’t really tell the whole story.

“The IO control is one of the most overlooked but most powerful things in the Dominator ECU. The system cleans house when it comes to the number of physical connections available, but when it comes to inputs and outputs, that’s not where you should be focused. For example, cooling fans – the OEMs control cooling fans in a hundred different ways in a factory application.

“But on most aftermarket EFI systems, there’s a very limited window for fan control,” continues Vanderhoof. “Some will simply trigger the fan at a certain engine temperature, but the Dominator takes things several steps further. We can turn the fan on above a certain RPM, a certain temperature, below a certain wheel speed, at a certain throttle position, and so on. It’s something that might not be obvious when looking at a spec sheet, but it makes a huge difference in practice.”

Vanderhoof points out that the software’s design also translates to better results right out of the box as well as features that are ultimately more useful.

“The software is really approachable without feeling limited – aside from MoTec and stuff like that [which is aimed at a different customer and comes with a much higher price tag to match], the Dominator’s fuel control is second to none. When I’m getting a new car up and running, I can put together a fuel map and, as long as all of my information is correct, I’m usually within five or six percent of where it wants to be the first time I fire up the engine.

Some of that comes down to experience,” continues Vanderhoof. “But it’s also because the system is using all of the correct parameters to calculate fuel flow – a lot of other manufacturers don’t. I have yet to find another system that makes accurate fuel control this easy. And you have the ability to do pretty much whatever you want with the advanced tables, too. Those tables take a strong foundation and allow you to customize it to your exact needs for that specific car. We use those for all types of stuff – fuel modifications, timing modifications based off of wheel speed, or front-versus-rear wheel speed, etc. You can easily do all of that with the Dominator EFI system.”

And the Dominator’s ability to support a dual-fuel system can also be particularly useful for drag-and-drive events.

“Staged injection allows you to control multiple sets of injectors independently of each other,” Witte explains. “You can use it to control multiple very large injectors, like what you might find on a small engine running a lot of boost. In that case you might only want to run a few of the injectors at idle and low-power conditions, and then you’ll turn on more of them as fuel demand increases. Some people in the drag-and-drive world also like to switch fuels depending on whether they’re driving on the street or racing at the track, and you can do that as well. You swap between a set of injectors running one type of fuel and another set running a different type of fuel on the fly. Or, more commonly, you can just load a different tune that uses the other set of injectors and you’re ready to go.”

Form And Function

Witte tells us that the key to making these features accessible and useful to a wide range of users was to make the hard stuff look simple.

“That means we try to reduce the number of parameters that a person has to use in order to get value out of some function of the ECU. A good example of that is boost control. On one end, you have the user who might not be really well-versed in boost control, and they just want it to make boost. For them, we have a drop-down with, say, five settings that they can try, and then decide which one gives them the best boost control. But for the user who wants to dig deeper into it, there’s also a sixth selection on the drop-down menu called Custom, which unlocks all of the controls and settings, so you can make all of the manual adjustments you want.”

In the years since the original Dominator EFI system’s introduction, its functionality has expanded substantially, with a steady series of software updates that have often delivered much more than just bug fixes.

“Since the original system launched, we’ve added boost control, traction control, the advanced tables, support for additional transmission types, and other new features,” Witte says. “And the goal is to make each new version more refined than the one that preceded it. And along the way, we also add features that might not make headlines, but can prove to be very useful, like PIN MAP test mode. That allows you to turn any one of the pins on the ECU on or off to test it. That can be really handy for troubleshooting if you think you might have a bad injector or something like that. Just unplug it, go to the test mode, turn the output on, and check it with a test light or a voltmeter. It can really come in handy if you’re doing your own custom wiring harness, too – you should check every single pin with that before you try to start it.”

Vanderhoof is also quick to point out that software updates often usher in refinements that make the system more intuitive to use.

“With some of the other systems that are out there, it almost looks like someone has just copied-and-pasted an Excel spreadsheet into their software. If the interface isn’t well thought out, it not only makes the system cumbersome to use, it also kind of makes you question the quality of the product itself. It might seem silly, but small refinements can really affect ease-of-use, and by displaying instantly recognizable icons at the top of the toolbar in the Holley software, it really makes life a lot easier. If I want to make changes to boost control settings, I can just click on the little turbo up there. Oh, and there’s a little fuel injector up there, too – that’s probably where my fuel is.”

That sort of attention to detail can have a meaningful impact on the overall user experience, which is part of the reason why the Dominator EFI system has stood the test of time. “It makes it easy to pick things up quickly,” he adds. “If I show a Holley system to someone who has always tuned EFI with something else, they’re up and running in 30 seconds.”