Tech: Holley Dominator EFI Vehicle Management System
In the world of performance engine management, there are a number of options from which the end user can choose. One of those systems, the Holley Performance Products Dominator EFI Vehicle Management System, has been turning heads as of late, thanks to its full-featured capabilities and a function list designed for both street and racing applications.
Controlling the many different engine parameters presents numerous challenges, and the Holley engineering team had a number of specific goals in mind when they set out to create a world-class design, chief among them the ability to control all aspects of vehicle management within one box.
“Basically, we were looking for full-featured functionality, but ease of use at the same time,” explains Doug Flynn, Holley’s chief engineer on the project. “We didn’t want someone to have to be a professional engine tuner to be able to use the user interface. At the same time, we wanted to give a reasonable amount of features so that the professional tuners would have what they needed. It’s always a compromise, but at the end of the day we wanted to make the best unit we could. It was very important for us to have a welcoming interface for the end user. What we’re trying to do is open the door for people who might have been scared to get into doing their own tuning.”
- Twelve sequentially driven 8:2 peak and hold injector drivers with multiple staged injector strategies
- A pair of wideband oxygen sensors (shown above) enable the Learning Mode and help simplify the tuning process.
- Twelve channel Distributorless Ignition (DIS) outputs capable of directly driving “Smart” ignition coils or Holley DIS coils.
- Plug and Play control of factory GM 24x and 58x LSx engines
- Integrated electronic transmission control.
- Integrated dual channel wide band oxygen sensor controls.
- Integrated drive by wire throttle body control.
- 4 stage progressive nitrous control
- Turbo boost control
- Integrated water/methanol injection control
- Integrated “Data Acquisition and Control”
- Internal data-logging standard with a huge 2GB of memory
- Self-tuning fuel table strategy
- Store and change between four calibrations
- Individual cylinder fuel and spark control allows you to unlock your engine’s potential
- See the Full Feature List
“With some systems on the market, the interface looks like a spreadsheet,” continues Flynn. “That’s what engineers like and are used to, but having a whole bunch of parameters and numbers crammed into one screen scares the novice user. It takes a lot more effort on our end to make things pleasing.”
That effort is certainly appreciated by the racer as well as the novice user.
“It’s super-simple,” praises longtime engine tuner and NMRA Renegade racer Tim Matherly. “When I initially put it on my car, I over-complicated everything, as I’m used to tuning some of the other systems on the market. This thing, you plug in your injector size, and the car starts – you choose a fuel map and then the learn function will adjust it, just like that.
“I can literally tell you, I made three pulls on the dyno and left for the NMRA Florida race,” adds Matherly. “It has different base fuel maps for different applications, which gives you something to start with. Then you just walk through the paces, which ignition system you have, your cam sensor, your crank sensor, and once you put all of that into the map, you load the file into the computer, and that’s it. Once you tell the car what air/fuel ratio you want in specific situations, like idle and midrange, the system will then adjust the fuel map as it learns. You tell it what you want and where you want it, then go out and make a pass, and it corrects itself to work from there.”
Matherly also recommends the Dominator to street enthusiasts who frequent his MV Performance shop in Winder, Georgia.
“I’ve got a customer with a ’79 Pinto and a turbo 4-cylinder using it, a ’67 Barracuda with a Hemi using it, a Z06 with an LS3 onboard, cars like that,” he says. “We even tuned a drift car from Road Atlanta. Rick Anderson from Holley was there with the customer and they were having trouble getting it to run right. We got it on the dyno and played with it a little bit to sort it out, and the customer ended up ecstatic with how well the car was performing.”
Continuous feedback from units in the field
Since Holley has a number of operatives out in the field, working with its products in conjunction with some of the big-name tuners like Matherly, the company constantly receives real-world feedback about the product’s performance.
“You can actually drive the car around and feel the system making changes on the road,” says Anderson. “Once you pass that point, like with a race car, you’re going to give it control in certain areas and not give it control in certain areas, like at low rpm with that bigger camshaft. That will need to be tuned in.”
“One of the best features has been how well the closed-loop control has worked,” says Flynn. “The learning feature has allowed for a lot easier use of tuning and has provided a safety net for people when their tuning has been off. It’s saved them from damaging the engine so that they can go back figure out the tuning process. The other big thing about the Dominator is that we have everything integrated into the one box.
“We have a lot of customers out there where the only electronic component in the whole car is the Dominator system. It runs the ignition, boost controller, nitrous controller, they are running coil-on-plug, and are also using it for data acquisition,” continues Flynn. “If the racer wants it that way, it can be the only box in the car But it doesn’t limit the customer – if they are familiar with, or already have a Racepak and want to integrate the Dominator system with it, there is a module that can be purchased from Racepak that will take our data and display it on the Racepak software.”
Depending on how mild or wild the engine is, for a street engine, up to a certain camshaft, you can basically set the target air/fuel ratio and let the system do everything. – Rick Anderson, Holley EFI
Flexibility is key design features
“We don’t hard-code the system inputs and outputs. Some of the systems on the market say, for example, ‘this input has to be turbo shaft speed input.’ That’s what it’s called and that’s what it’s named, and a lot of times you run out of inputs and outputs,” explains Flynn. “We permit the user to define the inputs and outputs, which does create a little bit of complexity for the user, but that’s not been a hurdle. We let people define those extra inputs and outputs and it gives them the opportunity to do a lot of unique things that they can design within the software.”
Installation of the product is relatively straightforward, although there are a number of precautions.
“The wiring installation and making sure it is done properly is the number one key thing for the success of any engine management system,” says Flynn. “You also need to make sure that the electronics are not in a noisy environment. That’s the secret to having the product work well down the road. Once you do things wrong, you’re going to fight it forever. People don’t understand how critical good grounds and just good general wiring practices are; they tend to blame the box when things don’t work properly when many times it’s the actual hardware installation.”
Holley wiring tips
Each of those features mentioned previously, like the boost controller and nitrous controller, are not just basic designs but rather full-featured component controllers that are capable of handling the extreme combinations that a customer can design. For example, the nitrous controller utilizes a four-stage progressive design that will support wet and dry types in both progressive and non-progressive iterations. On the Nitrous Parameters screen, each stage is enabled, the TPS trigger point is set, and the rich/lean cutoff air/fuel ratios are programmed. Each stage has its own setup page where type (wet/dry, progressive/non-progressive) are inputted into the system’s controls, and the RPM trigger/cut-off points, delay, progressive control and even closed-loop settings are also programmed on this screen.
The boost controller setup is of a similar design. Boost is controlled versus time, speed, engine rpm, and can even be controlled versus time and speed in each gear. There are multiple control strategies that allow control of the wastegate dome pressure or control of the actual manifold (boost) pressure. These two items can be controlled in both open or closed-loop modes.
Datalogging is handled by PC or internal logging, and the number of items along with the rate of logging are all programmed in the Datalog dropdown menu. Triggering of the system is handled a number of different ways – upon engine start, rpm, TPS, nitrous activation, oil pressure reading, and even a simple toggle switch. There is a data overlay feature that permits the log to be traced on any screen in the tuning software, making it ideal for situations where you are trying to track down an problem, for example intermittent nitrous activation. A whopping two gigabytes of internal memory is on-board, so there are no worries about losing a tiny SD card.
Another cool feature is the option to control a water-methanol injection system for those of you with boosted street cars looking for that extra edge. With the Dominator EFI system, you can program the percentage of flow your engine requires as a function of injector flow, meaning that there are no opportunities for over- or under-injection – the tuning is based on engine RPM and load. The only caveat is that you need to use Holley’s solenoids and nozzles as they are flow-characterized specifically for use with the Dominator’s design.
As Flynn discussed earlier, this system can be the only electronic device in the car, and that holds true even for late-model vehicle owners who are looking to use electronically-controlled transmissions and the like.
“We don’t charge extra for the features that are built in. We include all of the hardware in the ECU. If you get a Dominator ECU, the ECU can control an LS1 engine, a 4L80E transmission with lockup converter, drive-by-wire throttle body, and that’s standard – every ECU is the same and it’s all included in the box,” he says.
But don’t think you’re stuck using just Holley equipment – if a customer is comfortable using their MSD ignition, that can be controlled with the system as well. It’s as simple or complex as you want to make it, and in our eyes that makes it a winner. In a bit of a departure from the norm, Holley’s EFI software is on their website, free for consumers to download and inspect.
“Anyone can download it, look at it, and play with it. There are already a bunch of tunes on there, so if someone wants to open a tune and see how it relates to their car before they buy anything, they can do that,” adds Anderson.
Taken at face value, this system is chock-full of features that can benefit anyone from the weekend warrior to the hardcore heads-up racer – take a look and see if you don’t agree.