Mark Houlahan
Brand Manager, Mustang Monthly
October 25, 2011
Photos By: Courtesy the Manufacturers

Many people think fuel injection is akin to the dark arts, like Voodoo or something, but it's not really that scary if you understand the basics of how an electronic fuel injection (EFI) system works. Without sounding like geeks in white lab coats, EFI is, essentially, a more precise way to control the fuel requirements of an engine. Where a carburetor is sized to an engine by its cfm rating and certain sized fuel jets are used to control fuel flow to the engine, EFI does the same thing via the cfm rating of its inlet, called a throttle body, and by the EFI's fuel injectors. Think of the injectors as an electronic version of a carb jet, only they can vary in size, making the EFI system more precise for the engine's fuel demands.

While we're over simplifying the typical EFI system here, we're just trying to help those who feel EFI is out of their range of comprehension by doing exactly that, keeping it simple. A whole separate story could be written on EFI theory (frankly whole books have been written on it) and if we really wanted to scare you we could talk about building, literally, with a circuit board and soldering iron, your own EFI computer. But that's not what we want to do. We want to put your mind at ease when it comes to EFI systems, which is why we're going to concentrate on easy-to-install, complete EFI conversion kits only for this buyer's guide.

A lot of technology and ingenuity have gone into the latest EFI systems. Just a few short years ago, many of the top aftermarket EFI systems were pretty much race oriented and required a laptop to even get the car started, let alone running at peak efficiency (hmm, maybe that's where all the scariness about EFI comes from). Today you can easily bolt on a manifold (or in some cases just a throttle body to your existing manifold); plumb some fuel system upgrades, and hook up a couple of wires. You can literally have some of these fuel injection systems up and running in less than a day with great benefits, including lower emissions, better fuel economy, easier starting, and more performance. For our buyer's guide, we scoured the market for complete bolt-on systems that featured either self-tuning capabilities, or came with their own handheld tuner so that no laptop or special software is required to get these systems up and running on your classic Ford. Check 'em out and join the 21st century!

Accel DFI

ACCEL has made a name for itself over the years with its custom programmable EFI system called Digital Fuel Injection (DFI). Now in its seventh generation, the Gen 7 DFI is a very capable and customizable speed density-based engine management system. The Gen 7 DFI electronics allow batch and sequential fire port injection and throttle body injection with individual cylinder control, along with coil-on-plug, coil pack, or single coil ignition setups. Many advanced features include boost controls, nitrous controls, two-step rev limiting, and more-all through an easy-to-use graphic interface software you install on your laptop. ACCEL's latest engine management, the Thruster EFI, offers plenty of user adjustable tuning features and is the backbone of its new engine builder plug-and-play packages.

(216) 688-8300
www.accel-ignition.com

Eight-Stack EFI
ApplicationFord 289/302, 351W, and 351C small-block, 429/460 and FE big-block, 4.6L DOHC modular
System Description50mm throttle bodies on cast manifold, fuel injectors, fuel rails, linkage, harness, ECM and software
Ignition System IncludedMust provide distributor and coil, with Redline and Electromotive management it is complete with coil packs and crank trigger
Fuel System IncludedMust provide fuel pump, fuel filters, fuel pressure regulator, lines, and fittings
Horsepower LevelUp to 650 hp
Optionsstack filters, dyno tuning
Retail PriceStarting at $5,195

Thruster EFI Engine Builder Kit
ApplicationFord 289/302 and 351W small-block
System DescriptionSequential multi-port EFI on a single-plane intake manifold with billet throttle body, high-flow injectors, billet fuel rails, wideband O2 sensor, ECM, and wiring, built-in data logging
Ignition System IncludedDual sync distributor, DFI 6A ignition, DFI E-core coil
Fuel System IncludedFuel pump, DFI billet fuel pressure regulator, most provide own lines
Horsepower Level475-700 hp
OptionsElectric fan control, custom built orders
Retail Price$4,147.95-$4,620.95

Edelbrock

The Edelbrock Pro-Flo 2 EFI systems are complete, fully sequential, EFI systems designed to convert from a carburetor to the efficiency of fuel injection in one kit. Edelbrock's Pro-Flo 2- and XT-based EFI systems include a handheld controller for easy setup and tuning, yet can still be optionally tuned via laptop if the user so chooses. Edelbrock even has the capability of its support staff "seeing" your software calibration during a support session. The EFI system comes with two different tuning strategies built in, speed density (engine speed vs. manifold pressure) and Alpha-N (engine speed vs. throttle position) and even base calibrations to get your Ford up and running quickly. The system uses an included narrow-band O2 sensor and is wideband O2 sensor compatible.

Edelbrock's new Pro-Flo XT EFI systems use the same electronics, including the handheld controller, but that's where the similarities end. The Pro-Flo XT features a more modern look with an OE-style long-runner intake and large 90mm front-mount throttle body. The wiring harness on the Pro-Flo XT also includes a bulkhead connector for easy disconnection and removal for servicing the engine or for engine removal.

(800) 416-8628
www.edelbrock.com

Pro-Flo XT Multi-Point EFI
ApplicationFord 289/302 small-block
System DescriptionLong-runner intake manifold, 90mm throttle body assembly, fuel rails, 29- or 44-lb/hr injectors, wiring harness, ECM, handheld calibration module, software
Ignition System IncludedMallory distributor, must provide your own coil
Fuel System IncludedFuel pump, fuel filter, fittings, and lines
Horsepower LevelUp to 450 hp with 29-lb/hr injectors, up to 650 hp with 44-lb/hr injectors
OptionsAs cast or black powdercoated manifold, larger injectors, larger fuel pump, coil-on-plug conversion
Retail Price$4,309.95-$4,569.95

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Pro-Flo 2 Multi-Point EFI
ApplicationFord 289/302 and 351W small-block, 390-428 FE big-block
System DescriptionIntake manifold, throttle body assembly, fuel rails, 29- or 44-lb/hr injectors, wiring harness, ECM, handheld calibration module, software
Ignition System IncludedMSD (small-block) or Mallory (big-block) distributor, must provide your own coil
Fuel System IncludedFuel pump, fuel filter, fittings, and lines
Horsepower LevelUp to 450 hp with 29-lb/hr injectors, up to 650 hp with 44-lb/hr injectors
Optionslarger injectors, larger fuel pump, coil on plug conversion
Retail Price$3,359.95-$4,111.99

FAST (Fuel Air Spark Technology)

Walk through the pits of most any Sportsman racing event and you're bound to find FAST EFI equipment in many of the race cars. The FAST XFI systems feature a broad range of operating parameters, options, and scalability. The XFI system is available with Ford wiring harnesses and ignition adapters for the late-model TFI-style distributor, but because it's purchased in kit form, we're going to limit the XFI system to this mention here, but if you need the laptop tuning ability and customization, the XFI system should be on your list of EFI systems to look at. With that said, the folks at FAST know that the XFI system can be a bit challenging for the bolt-on crowd that simply wants to yank their carb off, go EFI, and reap all the benefits. That's why FAST has developed its EZ-EFI self-tuning EFI systems. On the market just a few short years, the EZ-EFI is available as a throttle body system, complete multi-port system, and even a multi-port retrofit to use with a factory manifold setup (great for swapping a factory EFI 5.0L Mustang engine into a classic). All EZ-EFI systems are speed density based.

(877) 334-8355
www.fuelairspark.com

EZ-EFI 4150-Based EFI
ApplicationAny 4150-style flange intake manifold
System Description4150 carb flange throttle body with built-in fuel rails and 88-lb/hr injectors, wiring harness, ECM, handheld calibration module, wideband O2 sensor (Master Kit includes fuel pump, filter, lines, and fittings)
Ignition System IncludedMust provide your own distributor and coil
Fuel System IncludedOnly included with Master Kit system
Horsepower LevelUp to 550 hp, dual quad option supports over 1,000 hp
OptionsDual quad kit, fuel pump kit, universal in-tank fuel pump kit, multi-port retrofit
Retail Price$1,802.45-$2,371.23

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EZ-EFI Multi-Port EFI
ApplicationFord 289/302 and 351W small-block
System DescriptionSingle-plane intake manifold, billet throttle body assembly, fuel rails, injectors, wiring harness, ECM, handheld calibration module, and fuel pump kit
Ignition System IncludedMust provide your own distributor and coil
Fuel System IncludedIncludes fuel pump and fuel filters, must provide fittings and lines
Horsepower LevelUp to 1,000 hp
OptionsFuel pump hose and fitting kit
Retail Price$2,667.39-$3,593.51

Holley

With a name like Holley, synonymous with fuel delivery, you know Holley has something to offer for aftermarket bolt-on EFI systems. Indeed, Holley has been involved with EFI systems for decades and has recently relaunched its aftermarket EFI business under the umbrella of "Holley EFI" with several sub-families of EFI packages. We're mostly concerned with the Avenger and HP lines of EFI, as its Dominator line; while more than capable of running a street engine is not a whole-system solution, which is what we're focusing on in this guide. The Avenger and HP lines feature throttle body and multi-port EFI systems. The Avenger and HP EFI systems are speed density based and both feature self-tuning capabilities and utilize a handheld programmer for tuning inputs should you feel the need to adjust a parameter yourself. Additionally, the HP-based systems offer enhanced features like nitrous retard, boost control, distributorless ignition driver, water/meth injection control, internal data logging, and much more.

(800) HOLLEY-1
www.holley.com

Avenger EFI 2/4BBL TBI
ApplicationAny 4150-style flange intake manifold
System Description670- to 900-cfm cast throttle body assembly, injectors, wiring harness, ECM, handheld calibration module, wideband O2 sensor, and fuel pump kit
Ignition System IncludedMust provide your own distributor and coil
Fuel System IncludedIncludes fuel pump and fuel filters, must provide fittings and return line
Horsepower Level200-600 hp
OptionsUpgrade to HP-based ECU, oil and fuel pressure transducers
Retail Price$1,799-$1,999

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HP EFI Universal Multi-Port Retrofit
ApplicationAny 4150- or 4500-style flange intake manifold
System Description900-cfm cast throttle body assembly, wiring harness, fuel rails, fuel injector bungs, fuel pressure regulator, ECM, and wideband O2 sensor
Ignition System IncludedMust provide your own distributor and coil
Fuel System IncludedIncludes pressure regulator, must provide fuel pump, fuel filters, fittings, lines, and properly sized injectors
Horsepower LevelDependent upon injector size
OptionsFuel pumps, injectors, Ford TFI ignition adapter, oil and fuel pressure transducers, knock sensor
Retail Price$1,849

HP EFI 4BBL TBI
ApplicationAny 4150-style flange intake manifold
System Description900-cfm cast throttle body assembly, 75- or 85-lb/hr injectors, wiring harness, ECM, handheld calibration module, and wideband O2 sensor
Ignition System IncludedMust provide your own distributor and coil
Fuel System IncludedFilters included, must provide your own fuel pump
Horsepower LevelUp to 525 hp (75-lb/hr injector), up to 600 hp (85-lb/hr injector)
OptionsKnock sensor, oil and fuel pressure transducers, 5.7-inch touchscreen controller, Ford TFI ignition adapter
Retail Price$1,749