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Today's hot-rodding and muscle-car landscape offers enthusiasts the potential for more power and more tunability than ever before. Gone are the days when a four-barrel carburetor was the only choice for building significant power, as Holley's electronic fuel injection systems ushered in a new era of performance controllable through a single handheld computerized interface.
Most notable among these systems are the company's Super Sniper EFI 650 and Super Sniper EFI 1250, along with its Sniper EFI XFlow systems. Each feature several advancements that allow the enthusiast to implement electronic fuel injection onto their existing engine easily — whether it's naturally aspirated, boosted, or even nitrous-injected.
There are several flavors of these units, so we enlisted the help of Holley Fuel Injection Systems Engineer Matt Lunsford to detail the differences. Together we break down where an enthusiast might want to switch from one to the other and explain the valuable features each of the different units offers to help you choose the right system for your application. Each of the Super Sniper units is based around an 825 cfm Holley EFI throttle body.
Holley has manufactured its original Sniper EFI systems for some time now, but the Super Sniper systems offer additional features and capabilities and the familiar, integrated ECU of the original Sniper systems, which greatly simplify wiring as there are no other modules to mount underhood or in the car.
"Super Snipers have the ability to handle draw-through supercharging, as well as blow-through, whereas the normal Sniper only can do a blow-through boosted application. The main body is machined to allow you to reference the manifold air pressure sensor below the blower with the draw-through sitting on a positive-displacement blower; with the normal Sniper, it's not," says Lunsford.
Remember that for those not needing boost control, the original Sniper systems will support the same 650 horsepower as the Super Sniper 650.
Super Sniper systems offer a simple upgrade from old-school carburetion to modern fuel injection all in one package. And if you're running boost, even better — these throttle bodies accept your blow-through carburetor hat and even work on draw-through roots-style blowers with ease.
The Super Sniper 650's quartet of 100 lb/hr fuel injectors supports 650 horsepower while offering boost control capabilities for those small-turbo and blower applications so prevalent today. This system is designed for those lower-horsepower engine programs, as long as the user doesn't exceed the fueling capabilities of the system. There is a great demand for systems that can support this power level, and the Super Sniper systems provide extra features that the standard Sniper systems do not offer. Additionally, a significant advantage all Super Sniper systems have over non-Super units is managing boost with a boost controller.
The notable difference between the Super Sniper 650 and Super Sniper 1250 is the fueling capabilities; where the 650 unit has four injectors, the 1250 unit adds four more injectors to support the increased demand of high-horsepower, high-boost applications.
When a customer is on the performance edge of the 650 unit, Lunsford always directs them to the higher-horsepower unit to ensure their satisfaction.
"I ask about their goals and the engine’s potential. If it's more than 650 horsepower, it's always, 'Put the 1250 on it and be done with it — the eight-injector version.' If they say, 'It’s going to make 450 horsepower, and it's got a turbo that makes 6 pounds of boost. What do I do?' They have the option of doing a 650 Sniper or 650 Super Sniper. In that instance, the differences are, 'Do you need boost control? If you have a supercharger that's not even a deciding factor. If you need boost control, you've got to do the Super Sniper, even if it's only making four or five pounds of boost,'" he says.
The Super Sniper 1250 systems feature eight 100 lb/hr injectors in the throttle body to support up to 1250 horsepower with self-tuning capabilities, while 650 Super Sniper systems use four injectors. Even a tuning novice can be successful with fuel injection using one of these systems. The fuel injectors hide in what would be the bowl area of a traditional carburetor.
All Super Sniper systems have a long list of shared features controlled by the easy-to-use handheld programmer, which walks the user through the programming options. The self-tuning ECU ensures that the vehicle runs properly when the tuning process is completed. The user answers several questions about the engine's specifics using Holley's Calibration Wizard, creating a base fuel map utilizing data Holley has on hand from thousands of engines. The ECU then continues the learning process as the engine runs using the system's wideband oxygen sensor, optimizing the map to the individual vehicle to provide the user with a seamless installation that performs as advertised.
Lunsford says both Super Sniper systems offer three configurable inputs, which can be outfitted with pressure transducers to read transmission line pressure, oil pressure, fuel pressure, or any other pressure in the engine the user wants to monitor.
"Even if you don’t have a supercharger and you just want to monitor your oil and fuel pressure electronically in a data log or on the handheld, the Super Sniper 650 four-injector version is the way you'd go because then you can plug in an oil pressure sensor and a fuel pressure sensor and you can have it live as you're driving down the road," he explains.
Throttle body with ECU exposed: The self-contained installation is part of the Super Sniper and Sniper XFlow appeal. The ECU mounts inside the throttle body, and only the necessary wiring is routed through the unit to provide easy hookup to the required sensors for the application.
● User-friendly Boost Control with handheld adjustability
● Programmable Target Air Fuel Ratios per Boost level
● Advanced boost control is available via free Sniper EFI tuning software, including Boost vs. RPM and Boost vs. Time – Same popular boost control offered in Holley HP and Dominator EFI systems!
● 2.5 Bar MAP sensor included which safely works on applications up to 21.5 PSI
● Built-in Single stage progressive nitrous control
● Dry or Wet Nitrous Support
● Progressive or Non-Progressive control strategies
● Lean/Rich AFR Cutoff
● Time or RPM-based Timing Retard and much more!
● Integrated ignition timing control for precise timing curves
● Programmable inputs and outputs
● Three Programmable 0-5V Sensor Inputs for Oil/Fuel/Dome or Nitrous Pressure Sensors
● Six Programmable Ground Outputs
● One +5v Reference Output - +5V Power Supply for 0-5v Sensors
● One Sensor Ground – Ground supply for 0-5v Sensors
● Internal fuel pressure regulator eliminates the hassle of plumbing an external fuel pressure regulator (Preset to 58.5 PSI) for N/A or Nitrous applications
Super Snipers shine in blow-through applications such as this 1,000hp ProCharged small block.
The Sniper EFI tuning software offers the same types of controls as Holley's HP and Dominator EFI systems, with boost control and advanced tuning capabilities as the most significant advancements in the Super Sniper series of EFI systems. The user configures boost timing retard in degrees using the Sniper EFI tuning software and handheld touchscreen display as the boost ramps in, can set air/fuel ratio boost offset (add fuel as boost comes in), and target specific air/fuel ratios at idle, cruise, and wide-open throttle. The included 2.5-bar Manifold Absolute Pressure sensor monitors boost and sends that information to the system.
For nitrous racers, the built-in single-stage progressive controller is initially set up through the Sniper EFI software and is subsequently adjusted using the handheld programmer. Timing retard for the nitrous system is either RPM or time-based and is altered at the touchscreen. A lean/rich cutoff point can be implemented for engine safety.
Each Super Sniper also works with Holley's digital dashes and analog-style digital gauges. Super Sniper throttle bodies are dual-drilled for 4150 and spread-bore fitments (spread-bore applications should use Holley's Spread Bore Sealing Plate (PN 9006). The OE-style throttle position sensor and idle air control sensor are designed for years of trouble-free service. These systems also interface with Sniper's Hyperspark ignition, MSD billet distributors, and MSD capacitive-discharge ignition systems.
The 650 and 1250 units are each available in three finishes.
● Super Sniper 650 Black Ceramic: 550-519
● Super Sniper 650 Classic Gold: 550-520
● Super Sniper 650 Shiny: 550-518
● Super Sniper 1250 Black Ceramic: 550-513
● Super Sniper 1250 Classic Gold: 550-517
● Super Sniper 1250 Shiny: 550-512
But wait — there's more! Remember we mentioned the Sniper XFlow systems back at the beginning of the article? The Sniper XFlow systems include all of the great features of the Super Sniper systems and add CNC contouring to the throttle body, which boosts the flow rate to 900 cfm. The standard XFlow 4-injector unit uses 120 lb/hr injectors and supports 800 naturally aspirated horsepower, while the 1375 eight-injector systems support 1,375 boosted ponies. There are no other functional differences to the XFlow systems, only the ability to support more power thanks to the contoured throttle body openings and upgraded injector capabilities.
● Sniper EFI XFlow Black Ceramic: 550-541
● Sniper EFI XFlow Classic Gold: 550-542
● Sniper EFI XFlow Shiny: 550-540
● Sniper EFI XFlow 1375 Black Ceramic: 550-545
● Sniper EFI XFlow 1375 Classic Gold: 550-546
● Sniper EFI XFlow 1375 Shiny: 550-544
If you are in the market to upgrade your carburetor-equipped ride to something more modern — and add significant boost-handling capability along with many other useful features — then look no further than the Super Sniper and Sniper XFlow electronic fuel injection systems. They're packed with the goodness you've come to expect from Holley EFI and will support today's big-power boosted and nitrous engines with ease.
The user must enable and set up the nitrous controls with the Sniper EFI software before it's available on the handheld controller. Activation and shut-off RPM and functions like system-on delay and length of activation in time are controlled here. Nitrous timing retard is adjustable using the handheld using either time or RPM-based strategies. For boosted applications, the user dials in the amount of timing retard desired when the vehicle is in boost from 0 to 5 degrees. The Sniper EFI software handles that seamlessly. The handheld unit displays the amount of retard selected as boost rises.
Super Sniper and XFlow systems require an external bypass fuel regulator in a boosted application. The Super Sniper systems have an integrated regulator for naturally aspirated use, but to accurately reference boost, either Holley's 12-848 Dominator two-port regulator (up to 800 HP) or two-port VR Series 12-851 (more than 800 HP) return-style regulators should be used.
Keep in mind that to support all of this horsepower from your ride, you're going to need the appropriate fueling capabilities to support it. Holley offers a massive range of vehicle-specific drop-in fuel systems, along with brand-new tanks, pumps, regulators, and filters along with Earl's plumbing items — as part of kits or available separately — that will support these power levels with ease. Whether you need an in-tank retrofit module with Holley's Hydramat filter attached or an externally-mounted pump solution, Holley has what you need.
"For your 650 horsepower Super Sniper user, or even your XFlow user at that lower horsepower level, the four-injector units, our drop-in modules have 450 liter-per-hour pumps. Anything more than that, you end up really needing an external bigger pump," says Lunsford.
"We even have some of the muscle car pumps where can take out the factory pump and sending unit to replace with our product — a fuel pump on a stick, basically. You now have a return-less system for your EFI car. We now have those with higher flow pumps on them as well. So now you don’t have to put a fuel cell in your car or anything of that nature, and you can support higher horsepower in your older retrofit cars."