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Testing Out The New Holley 1,500HP-Capable Sniper Dominator EFI System

Testing Holley’s new Sniper Dominator EFI system

Jeff Smith Jan 15, 2019
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Make it bigger. That was the plan.

Holley’s Sniper throttle body fuel injector has been a big success—so what do you do to follow that up? Make it bigger—which explains the Sniper Dominator. Think of this as a regular Sniper on steroids. It sits on a 4500-series mounting flange with 3.125-inch throttle bores and eight 100-lb/hr injectors that will feed up to 1,500 naturally aspirated horsepower (1,250 hp forced induction) on gasoline. This is throttle body fuel injection in the large-by-huge size. And it comes with a ton of features—intended more for the race community but we will likely also see this beast on the street.

The features that either come standard or can be added to the Sniper Dominator make it an excellent upgrade for a serious street or drag race big-block. Holley suggests that the engine be capable of at least 800 hp, but among the features are opportunities for either a single stage of nitrous or draw-through or blow-through boosted power from either a crank-driven supercharger or turbos. The Sniper comes with a built-in 2.5-bar MAP sensor that can support up to 36 psi, but you can go higher as there is a provision for an external MAP sensor.

001 Holley Sniper Dominator EFI Dyno 2/13

Converting a carbureted big-block Chevy, for example, to a Sniper Dominator involves more than just bolting on the throttle body since a dedicated EFI fuel delivery system is required. But short of that, yes, you just bolt it on and make a few simple electrical connections.

Features abound on this system, but initial simplicity is the name of the game so you only have to make four simple connections to make this Sniper work: 12v positive and ground direct contact with the battery, a link to an rpm source, and a switched power connection. But the Sniper Dominator offers plenty more opportunities. The idea is to perfect control over both the fuel and spark side of the horsepower equation.

The basic Sniper Dominator operates off of a simple handheld device but for those who really want to pull out the demon tweak, there’s free, downloadable Sniper software that can be loaded on your laptop that offers plenty of other opportunities. For example, enable ignition control through the Sniper and the tuner instantly has access to features like a starting line two-step, boost control via either rpm or time, multiple 0-5–volt sensor inputs, and a slew of programmable ground-enabled outputs.

Of course, all the standard learning-based fuel trim options are also available. So to quickly install the system, you can input the necessary engine specs, create simple air/fuel ratio parameters for idle, cruise, and wide-open throttle (WOT) tuning. This will get the engine running properly but then a software system similar to the same screens used in Holley’s Dominator EFI system appears on your laptop to allow near infinite control over how the fuel and spark will be delivered to the engine.

002 Holley Sniper Dominator EFI Dyno 3/13

This is the Sniper with all of its electronic connections in its entirety. Not all of these connectors must be used, but with them, the installer/tuner has loads of options and opportunities. The wiring is simplified because the ECU is located on board the throttle body. Two finish options are available in addition to our “tumbled silver,” there’s also black and a retro gold color.

Rather than delve into all the Sniper’s features, we decided to put a Sniper Dominator to the test. The accompanying dyno information reveals that if the fuel flow numbers were closer together, the power numbers would have also been nearly the same, so increased power isn’t the point here. Instead, consider what the Sniper offers. Let’s start with bolting on EFI control on a carbureted manifold you already have. Add spark control, which is a no-cost, built-in feature and a separate digital spark curve box is something else you don’t need.

Moving to the nitrous side, there are digital nitrous controls that now aren’t necessary if you intend to go NOS-hunting for more power. If a turbocharger is on the agenda, then turbo wastegate control is also an excellent reason to go the Sniper route. Even if simply running NA is in the cards, the Sniper offers a built-in data logger that can be easily downloaded from an SD card so investing in a data logger is another investment not needed. The Sniper can even control the electric fans. Of course, all of this is included with feedback O2 sensor control of the air/fuel ratio that you choose. No more constantly chasing jets, adjusting float levels, or nitrous fuel flow numbers. With the Sniper, all that control is offered with a few simple keystrokes.

To put this Sniper Dominator to the test, Steve Brule at Westech offered to run this new throttle body up against a typical Holley Dominator carburetor. Frankly, we didn’t expect to see much of a difference, but it was worth running it through the test gauntlet nonetheless. Westech used its 489ci big-block mule engine configured with 13:1 static compression ratio, a 270/272-degrees of duration at 0.050 Comp hydraulic roller cam with 0.680/0.680-inch valve lift, and a 110-degre LSA. Topping this off was a set of AFR 325cc as-cast heads with a CNC machined chamber and a Weiand Team G single-plane Dominator flange intake.

003 Holley Sniper Dominator EFI Dyno 4/13

This is the handheld unit that can be used to initialize the setup and allow all basic and even some advanced tuning. This screen is from a different Sniper application, but the display is the same, revealing idle speed, air/fuel ratio, percent correction, coolant temp, and amount of correction applied. The system can accommodate three programmable 0-5V sensor inputs for oil/fuel/dome or other critical info such as nitrous pressure. Speaking of nitrous, there’s a build-in single stage wet (or dry) progressive nitrous control function.

As you can see from the numbers, the Sniper pulled out a slight power advantage. The maximum horsepower gain was 12 hp over the carburetor, but note that below 5,000 rpm the carburetor actually made slightly more power. Westech tuned this by attempting to match the air-fuel ratios of the Sniper to the carburetor. In our fuel flow graph, you can see that the Sniper flowed more fuel almost everywhere compared to the carburetor. At 4,600, the two curves almost overlap and the power difference is within 2 horsepower. If you really study the power versus fuel flow, it also shows that the Sniper would have benefitted and made more power if we had reduced the fuel flow slightly since below 5,000 rpm the carb flowed less fuel and made more power. The reason for pointing this out is that had the tuning been spot on for both the carburetor and the Sniper Dominator, the power numbers would have been much closer.

The bolt-on Sniper Dominator is not really aimed at the budget conscious searching for a cheap and easy way to make power. Carburetors still shine when it comes to inexpensive power. But the future for putting massive power to the ground is in finite control of spark and fuel. The Sniper Dominator offers the opportunity for both in a compact package.

004 Holley Sniper Dominator EFI Dyno 5/13

If you choose to load and use the laptop Sniper software, this is the base fuel map, expressed as a percentage of volumetric efficiency (VE). At the lower left which is low speed and low load, the VE is around 50 percent while at max load and max rpm in the upper right, the VE is over 100 percent. The advantage of using this software is the ability to make much more precise tuning adjustments to the fuel map.

005 Holley Sniper Dominator EFI Dyno 6/13

The Sniper software is very similar to the current Holley HP and Dominator spark and fuel maps. The Sniper laptop software affords the tuner the ability to control the spark as accurately as the fuel. If this seems a bit intimidating, then tuning shops—such as Westech Performance—can get you all dialed-in.

006 Holley Sniper Dominator EFI Dyno 7/13

One place where Holley’s enhanced software can pay big dividends is with launch control. This screen illustrates how retard can be ramped in and back out to control power over time. This is especially helpful in cars that are “traction challenged” off the line. The programmable launch control can be triggered by a trans-brake input. There’s also a boost control feature that can even control a secondary fuel pump (TPS, RPM, or boost enabled)!

007 Holley Sniper Dominator EFI Dyno 8/13

This is the 1,150-cfm, three circuit Holley carburetor used as the baseline test for Westech’s comparison to the new Sniper Dominator.

008 Holley Sniper Dominator EFI Dyno 9/13

A quick glance might fool you into thinking that this Sniper Dominator is really a carburetor but its tuning potential is far greater. Holley put in extra effort to make the new Sniper Dominator look like a carb, and we think they nailed it.

009 Holley Sniper Dominator EFI Dyno 10/13

Westech used their 489ci, 13:1-compression Rat to test the Sniper Dominator against a not shy 1,150-cfm Holley Dominator. The power numbers were very close and the test was all about trying to come close to the fuel flow of the carburetor with the Sniper. As you can see from this dyno graph, at 6,400 rpm the win light went to the Sniper with 862 hp to the carburetor’s 848, for a gain of 14 hp.

010 Holley Sniper Dominator EFI Dyno 11/13

Holley lists this Sniper throttle body at 1,440 cfm using 2.125-inch throttle plates to move all that air. The unit also incorporates a 2.5-bar MAP sensor and is set up for -8 AN fuel lines. There are only four wiring connections: battery +, battery -, switched ignition, and rpm.

011 Holley Sniper Dominator EFI Dyno Test 12/13

The main reason for that monstrous flow capacity is that there are no boosters to impede the airflow. It’s also why Holley recommends this unit for engines that make at least 800 hp.

012 Holley Sniper Dominator EFI Dyno 13/13

As this fuel flow graph illustrates, the Sniper did flow a little more fuel than the carburetor, so if the fuel flow numbers were closer, the power numbers would have been closer as well. At 4,700 rpm, they actually are the same and not surprisingly, the power numbers were nearly identical. The Sniper isn’t about more power. Instead, it offers more finite control at a reasonable cost. In other words, you can have the tuning and driveability benefits of EFI without sacrificing performance.

Sidebar (1))

Dyno Chart
RPM Carb TQ Carb HP Sniper TQ Sniper HP TQ Gains HP Gains
3,600 642 440 639 438 -3 -2
3,800 660 478 650 470 -10 -8
4,000 687 523 680 518 -7 -5
4,200 716 573 712 569 -4 -4
4,400 738 618 731 612 -7 -6
4,600 743 651 741 649 -2 -2
4,800 749 685 747 682 -2 -3
5,000 753 717 753 717 0 0
5,200 755 748 757 753 +2 +5
5,400 752 774 763 784 +11 +10
5,600 751 801 760 810 +9 +9
5,800 745 823 760 834 +15 +11
6,000 733 838 743 849 +10 +11
6,200 717 846 726 857 +9 +11
6,400 696 848 706 860 +10 +12
  Sidebar (2)
Part Numbers
Description Part Number
Sniper Dominator EFI, 1,449 cfm, shiny 554-841
Sniper Dominator EFI, 1,440 cfm, black 554-842
Sniper Dominator EFI, 1,440 cfm, gold 554-843
Holley 1,150-cfm Dominator carburetor, red 0-80905RD

Photography by Jeff Smith


Holley Performance Products
Bowling Green, KY 42101



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