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-37% Sniper 4150 2x4 EFI System (Standard or Super)

Unfortunately, Holley is discontinuing the Sniper 2x4 and the colors an styles shown are available until supply is depleted and no more will be produced. Optionally, consider the Terminator X Stealth 2x4

The Dual Quad EFI System You've Been Waiting For!

The Sniper 4150 2x4 EFI System was hinted at for years before it was finally introduced. And why not--after all, the standard and Super Sniper 4150 EFI Systems have taken the automotive performance world by storm. It's an easy bet that folks with twin-carb tunnel-rams, cross-rams, and draw-through supercharger setups are going to want to ditch their problematic carburetors for one of these easy-to-use, self-tuning EFI Systems from Holley.

Like the single Sniper 4150, these are available in either a standard or a Super version. The Super version adds the same 8-pin I/O connector that allows you to add up to three 5-volt sensors including an external MAP sensor--critical to those who want to run this on a draw-through Supercharger setup. Unlike the individual Super Sniper, the Super Sniper 2x4 only has four injectors per throttle body (for a total of eight injectors) and is not available with 8 injectors per throttle body at this time.

So, how does this work? Simple: One of the throttle bodies is identical either to the standard 4150 Sniper or the 4150 Super Sniper with one exception: It has small injector sub-harnesses available. The second throttle body is devoid of sensors or ECU. It only has four injectors and two matching injector harnesses. Mate these together and the master Sniper throttle body (the one with the ECU and sensors) drives the injectors in the slave throttle body.

The slave throttle body has its fuel inlet relocated to the front, allowing the two to be placed more closely together--critical in some tight manifold situations. Because everything on the Master throttle body is identical, that means that everything that users have come to love about the single Sniper EFI System (such as the handheld display with Setup Wizard, Sniper software, built-in 2.5 bar MAP sensor and HyperSpark ignition system) all continues to work perfectly. That's right--even at this level of play no external ECU's, laptops or tricky wiring is required.

Choose From standard 2x4 or Super Sniper 2x4 Versions

  • Sniper 4150 2x4 PN: 550-527 (Shiny Silver), 550-528 (Ceramic Black), 550-529 (Classic Gold)
  • Super Sniper 2x4 PN: 550-531 (Shiny Silver), 550-532 (Ceramic Black), 550-533 (Classic Gold)

What Comes With the 2x4 Sniper?

Whether you opt for the Sniper 4150 2x4 or Super Sniper 2x4 EFI System, you get a nice set of included components and features.

3.5-inch LCD Touchscreen INCLUDED: Ok, if you've been following the Sniper EFI Systems from their inception you take this for granted. But do you realize that this is in our estimation the nicest, most capable, easiest to use setup/tuning/monitoring device of any EFI System in its class? For the majority of the users out there this handheld represents all the technology they will ever be required to use to implement their new EFI system. And that's a big deal.

CAN Bus to USB Adapter INCLUDED: Holley understands that the target audience for the 2x4 is a bit different than that of the single 4150 Sniper. Therefore they include the CAN-to-USB adapter cable at no additional cost. Like all Sniper EFI Systems, the adapter cable is not required since it is possible to move the configuration back and forth between the handheld and a PC. The cable just makes it much more convenient (and makes you look like a real guru in the pits when you connect your laptop to your engine!)


  • Direct Fit for Dual-Quad 4150-style Intake Manifold
  • The ECU is in the Throttle Body--No boxes to mount, no complex wiring harness to run!
  • Connect with as few as 4 wiring connections: Power +/-, Ignition, and RPM Signal
  • Bosch Wideband O2 Sensor for self-tuning capability
  • Visually amazing 3.5-inch touchscreen provides both setup and monitoring
  • Self-tuning--no laptop or software required!

Recommended With your Super Sniper EFI System

  • You will need an EFI Fuel System. We have several solutions!
    • A complete EFI Fuel Tank System is also a great choice. Be sure to opt for the 400 LPH pump if you will be making over 630 NA HP.
    • If no complete Tank solution is available for your vehicle but you still want the benefits of an in-tank pump then one of these Retro-Fit Fuel Tank Modules is the right answer. In this case, opt for the 450 LPH version to get the fuel you need to feed your 2x4 Sniper.
    • If you have a racing fuel cell with a 6- or 12-bolt flange around the filler neck then one of these Fuel Cell Tank Modules is ideal, with fuel pump options providing over 1000 LPH!
  • The Sniper 2x4 EFI Systems require an external fuel pressure regulator. We have a page dedicated to fuel pressure regulators that makes the selection process easy!
  • You absolutely will want a way to confirm your fuel pressure.  The Fuel Pressure Gauge is a cost-effective solution but with the added Super Sniper you can add a Fuel Pressure Sensor, allow you to display and data-log fuel pressure. Those who don't install one with their EFI system are invariably the ones who end up needing it.  Don't be that guy!
  • If you're not replacing an existing dual-quad setup then you might need this Cross-Link Bar to connect the throttle levers on the two throttle bodies.
  • The Super Sniper EFI System has the capability to control ignition timing in addition to providing fuel injection. If you choose this then we recommend you upgrade to the HyperSpark Distributor System.

Throttle Body Spacing Requirements

This usually isn't the first question folks ask but it's almost always at the top of the list. Holley has gone to great lengths to configure the throttle bodies so that they can be mounted as close as possible. In most cases that works out to 6.43 inches center-to-center. (Measure the distance between the air cleaner mounting studs if you currently have a set of carburetors in place on your 2x4 manifold.) Not that too many folks have this problem but you can mount the Sniper 2x4 throttle bodies as far as 13.5 inches apart (again, measuring center-to-center of the air cleaner stud, not the physical space between the throttle bodies.)

This Is Great But It's Not Exactly What I Need

We hear you. Maybe you have a need to control a GM or Ford electronic transmission. Or you want to run a coil-on-plug ignition system. Or you simply want throttle bodies that look more like carburetors.

Long before the Sniper 4150 2x4 EFI System was introduced we were custom-building Twin Quad Terminator EFI Systems. And those are going to continue to be a better answer in some circumstances. View the Twin Terminator Systems and let us know if you think that is closer to meeting your specific requirement.

Everyone says, "Buy From EFISystemPro.Com". Why?

When you buy it here at EFISystemPro.Com, that means we're on standby to answer your questions. Our level-3 tech support will gladly talk you through any challenge--just try to get that sort of personal service from a big-box auto performance store! Because here at EFISystemPro.Com, our look is high-end professional, but our service after the sale is home-town helpful!

Don't Miss This! FREE Sniper EFI T-shirt with every Sniper EFI system purchased from EFI System Pro!

This T-shirt is yours for $0.00 with your Holley Sniper EFI System purchased from EFI System Pro. Simply choose between Black and Dark Gray and designate your T-shirt size in the dropdown when adding the Sniper system to your shopping cart.

CLICK HERE for T-shirt product page

Watch This Great Video On The Sniper 4150 2x4 EFI System

Not Sure? Review this product documentation before you buy!

Owners & Installation Manual
Holley Sniper 4150 2x4 EFI System

Quickstart Manual
Holley Sniper 4150 2x4 EFI System

Wiring Tips
Holley Sniper EFI System

Boost ControlYes
DIS OutputsNone
Fueling StrategySpeed Density
Includes Power HarnessYes
Injector DriversEight
Internal DataloggingNo. All datalogging done via external CAN bus device such as 3.5-inch handheld (included), laptop software, or digital display.
Knock Control Channels0
Nitrous ControlYes
Number of Cylinders8 Cylinder (Even Fire Only)
User Configurable I/OYes
User-Selectable MAP StorageNo
Water-Methanol ControlNo
Displays And Controllers
Auto BrightnessNo
CAN Bus CapableYes (Specific to Holley ECUs Only)
Case/Bezel FinishBlack
ConfigurableMonitor dozens of pre-configured metrics provided by the ECU, including sensors, air/fuel ratio, switched outputs, drive-by-wire data, and more.
Data LoggingYes
Display TypeLCD
FunctionsSetup, Monitor, Tuning
Gauge/Display Size3.5 Inch Rectangular
Internal StorageYes (SD Card)
Throttle Bodies
Airflow Rate (CFM)800 CFM per Throttle Body (at 1.5 Inches Hg)
Barrels (BBL)4
Gaskets IncludedYes
IAC Motor IncludedYes
Injectors IncludedYes
StyleThrottle Body Injection
Throttle Bore Diameter (ea)42.86mm
TPS Sensor IncludedYes
Fuel Injectors
Flow Rate (Lbs / Hr)100 PPH
Fuel Pressure Regulators
StyleIntegrated in Throttle Body
Fuel Filters
Mounting Bracket IncludedMaster Kit Only: No
Harness Type7-pin Power/Ignition/Fuel Pump, 10-Pin I/O, Wideband O2, Coolant Temp, CAN Bus (All fixed to Throttle Body). Super adds second 8-Pin I/O Harness.
Crank Timing
Sensor Harness IncludedNo (Ignition Adapter Only)
TypeAir Temperature, 2.5 BAR MAP and Throttle Position (Integrated in TB); Coolant Temperature, Wideband O2
Also Included3.5-inch Touchscreen Display
ApplicationUniversal (Requires intake manifold for square bore carburetor or adapter there-to)
ColorStandard: Shiny Silver (550-527), Ceramic Black (550-528), or Classic Gold (550-529) Super: Shiny Silver (550-531), Ceramic Black (550-532), or Classic Gold (550-533)
Emission Code3
Unit of SaleKit

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Sniper 4150 2x4 EFI System (Standard or Super)

  • Views: 35502
  • Brand: Sniper EFI
  • Product Code: 550-527 | 550-528 | 550-529 | 550-531 | 550-532 | 550-533
  • Availability: In Stock
  • $2,616.00
  • $1,647.76

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