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.
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.
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.
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.
|RPM||Carb TQ||Carb HP||Sniper TQ||Sniper HP||TQ Gains||HP Gains|
|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