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We Dig Deep Into The Latest EFI Systems on the Market Today

Super Easy EFI: Why your next carburetor might just be a fuel-injection system

Chris Shelton Mar 23, 2016
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I’m of a particular generation. Well we all are, actually. But mine is the one whose auto shop teacher proclaimed that fuel injection would take over everything. And we found that patently comical. Fuel injection was more than just complex and costly back when Reagan was in office; it was entirely out of the realm of the garden-variety enthusiast. Sure, a few people whittled down OEM systems to work stand-alone; however, they were completely at the mercy of the few people in the country who could burn chips to make their systems work with relatively limited modified engines. So to us there was only one question: how on earth could fuel injection replace the simple and inexpensive carburetor? I mean, the idea sounded great and all but none of us were getting our hopes up about it coming true.

Well, brothers and sisters, we can officially say it happened: the day of simple and inexpensive fuel injection is here.

There was a sort of watershed moment at the 2015 SEMA Show. Three companies introduced 13 very affordable throttle body retrofit kits, many of which require no more than a couple of utterly simple programming entries. Though significant in its own right, the technology wasn’t the big news (self-learning injection dates back about half a dozen years). No, what truly stood out was the tipping point that the moment represented. Those 13 new products represent a 325 percent increase over the prior year! As impressive as that was, it almost paled in comparison to one more thing: three self-learning port-injection and several throttle body kits came in below the $1,000 barrier. And as incredible as that seems, one of those kits costs about what a high-end performance carburetor runs these days.

Too good to be true?

There’s real substance behind these claims. In a nutshell, most engines behave pretty consistently within a fairly broad spectrum of tune. It explains why a universal performance carburetor can make most engines run well enough on most engines to satisfy all but the pickiest of enthusiasts. In oversimplified terms, manifold pressure, engine speed, throttle input, and air/fuel ratio tell us what the engine really needs. So, in grossly oversimplified terms, the manufacturer has to create a generic fuel map to meet those parameters.

But this is where the right cross follows the left jab delivered by the generic tuning. The brains in this new generation of ECU constantly read the sensor parameters and—this is the technology that sounds as if it came straight from a rogue-robot film—learn the engine’s needs. So the ECU makes a note of every hiccup and changes the parameters in that area so it doesn’t happen again. Crazy, huh?

There are a few consistent elements among these systems. All of these systems control idle speed inasmuch as they maintain a user-set target speed. However, some of the advanced kits bump engine speed when the A/C clutch engages. Some systems are able to control a single cooling fan whereas others can control dual fans independently. The ones that control fans require external relays for fan operation. Some even control dual fans independently based on various parameters.

These aren’t just oversimplified carburetor conversions; they’re all incredibly sophisticated devices and some boast quite advanced features. For example, a number accommodate nitrous-oxide injection inasmuch as they alter timing and in some cases the fuel curve by user-set parameters. In fact, a few can control staged nitrous systems by numerous conditions like engine speed, manifold pressure, and throttle input. But all of the nitrous-friendly models require wet systems that inject their own fuel. Some systems have the capacity to drive the entire ignition system using the distributor only to send the spark to its intended plug; however, all are capable of operating as fuel controllers exclusively. The ones that control the ignition system can drive the coil directly or through an auxiliary ignition box like a multi-spark, capacitive-discharge system.

A few systems in this lineup boast Controller Area Network (CAN) technology. It’s a busing standard that lets various controllers in a system communicate with each other by way of a simple cable in a daisy-chain network. These systems accommodate other CAN-enabled components in a company’s catalog, most notably but certainly not limited to controllers for electronic transmissions like 4L60E gearboxes. They also communicate with other companies’ devices like gauge packages. One goes so far as to communicate with a vast array of components that use CAN technology, be they aftermarket or OEM. And while some are E85 compatible, understand that it comes with the penalty of reduced power, an inevitable shortcoming that has nothing to do with the fuel-delivery system.

What follows are what we consider the 18 most significant fuel-injection conversion systems—13 of those coming from the 2015 SEMA Show—and a truly unique problem-solving fuel controller. We also put together a chart to explain the various features at a glance.

This is a significant step in our industry’s evolution that puts enthusiasts at an entirely new crossroads, whether to keep one foot in the past or to take another step into the future. If only I had a time machine so I could go back and tell my teen-aged self. Well scratch that; I would’ve wasted decades wanting this day to come.


Edelbrock made an early entry into the EFI world in the 1990s, really not too long after it started manufacturing carburetors. For E-Street 2, its latest self-learning injection system, it called upon Magneti Marelli, one of the larger ignition and fuel-delivery vendors in the OEM world.

E-Street 2 boasts a number of premium features like A/C idle control and spark control. It offers one feature exclusive in the field: Bluetooth connectivity with Android-based devices. This lets Edelbrock offer each main kit in one of two ways: with or without a color touch screen programmer. Either the programmer or your own Android phone or tablet can be used to configure the system. The programmer or Android device displays a virtual dashboard of gauges and can be used to also alter various values for setup. Though entirely optional, a laptop can also alter the various settings.

We listed the main system (PN 3664) without the fuel-delivery system but Edelbrock offers E-Street kits with two fuel-delivery options. Part number 3665 includes the 3664 kit with a return-style fuel-delivery system. Part number 3667 includes the 3665 kit with a universal EFI sump fuel kit.


Edelbrock went straight to the OEM world for its E-Street system. Because an Android device can access all of the parameters via Bluetooth connectivity, Edelbrock offers the kits without the supplied tuning tablets. The tuning readout also boasts a virtual dash for tuning activities.


To call FAST one of the founders of the modern fuel-injection movement is a bit of an understatement. A second-generation ECU manufacturer, it initiated a revolution as significant as the stand-alone ECU was to the prior generation. Those systems may have given us injection but FAST gave us an altogether higher level of sophistication, power, and—most importantly—accessibility. They made tuners out of mere mortals.

FAST once again revolutionized the industry with a self-learning, plug-and-play ECU in 2009. More than the first on the market, it was the first to employ CAN technology. This technology lets FAST systems interface with other CAN-enabled components by a single plug, at which point they communicate seamlessly. Though the system is proprietary, FAST shared its CAN addresses with gauge manufacturers who offer CAN-enabled components. Most dyno manufacturers can also interface with these systems to record data straight from the ECU.

The company offers the kits seen here with single throttle bodies but offers duals as an option. Triggering a wet nitrous system initiates a user-set spark retard. Additionally, they can transform to accept E85 fuel by a simple change made in the handheld module. But the real news is the convertible nature of the ECUs; they will just as easily drive port injection systems, making system expansion much more affordable. In fact, FAST offers a multi-port variation of the plug-and-play design using the same EZ-EFI ECU.


EZ-EFI is FAST’s base entry in the retrofit market. It foregoes ignition control, and while it will work with a wet nitrous system, it won’t compensate for its use.


EZ-EFI 2.0 controls ignition with optional components and will compensate for a wet nitrous system by retarding spark. Its eight injectors give it a 1,200hp capacity.


EZ-EFI Multi-Port testifies to the EZ-EFI 2.0 ECU’s versatility by transforming to port injection, something all kits can do with some reconfiguration. The company offers it in two flavors: one with a 550hp capacity and another with 1,050hp capacity.


FAST XFI Sportsman Roots Blower debuted at the 2015 SEMA Show. It adds a second throttle body plus the capacity to work in supercharged applications, specifically on roots-type blowers. It supports self-learning but foregoes the hand-held controller for laptop programming. It also data logs, a feature exclusive to these four FAST systems.


FiTech had every one of its systems at the 2015 SEMA Show. The name is new but the company has significant roots in the injection-retrofit industry. About 15 years ago its principle, Ken Farrell, began introducing systems, the first inspired by the hot rodder’s favorite carburetor, the Stromberg 97. The brains within the company’s current self-learning systems are the result of a collaboration with Cal Poly engineers.

Some of the units accommodate supercharging, whether draw- or blow-through operation. Those units also handle wet nitrous injection but in a unique way, as the trigger with multiple conditions (engine speed, manifold pressure, etc.). Boost- and nitrous-enhanced versions also offer alternative spark and fuel maps. The systems also work with E85 fuel by configuring the ECU with the hand-held controller. All FiTech systems boast variable-speed fuel-pump drivers.

The big news for the budget-minded are two entries for less than $1,000. The really big news is the simple $795 Go Street model. But don’t confuse simple with unsophisticated. This unit shares most of its architecture with the other systems in the lineup. It just lacks some of the features like dual-fan control and special mapping for boost and nitrous applications. While it maintains idle speed to a user-set target, it won’t bump up idle speed for A/C clutch engagement. On the opposite end of the spectrum, FiTech applied the self-learning retrofit model to a port-injection system.


Go Street is the unit that has carburetors leaking little puddles in fear. FiTech kept prices low by eliminating features like ignition control, data logging, and optional laptop programming, and by supplying it with a one-color, joystick-controlled programmer. The company bills it as the entry-level carburetor replacement and the icing for a crate-engine cake.


As its name implies, Go EFI 600 supports as much as 600 hp. It also boasts the color touch screen controller, ignition control, data logging, optional laptop programming, and single-fan control. It’s also the company’s second model for less than a grand.


Power Adder 600 adds 25-psi boost and nitrous capability to the package. It does that by altering fuel and spark maps to suit supercharging (exhaust or mechanical) and nitrous injection. But more than respond to nitrous injection, everything in the Power Adder series can trigger nitrous based on various conditions. A second fan controlled independently from the primary fan comes with the package.


Power Adder 1200 doubles power capacity by doubling injector count (eight in one body). It also brings more sophistication to bear in the form of A/C idle compensation. Rather than merely maintain a target idle speed, it increases idle speed by a user-programmed amount whenever the A/C clutch engages.


Dual Quad is Go EFI 600 but with a second throttle body. Dual Quad Power Adder is Power Adder 1200 with a second throttle body.


Go Port 550 and 1050 are FiTech’s entries into the port-injected market. Functionally, they’re like the Go EFI 600 but with eight injectors mounted to the manifold. An arrangement with Edelbrock maintains one price respective of injector model regardless of manifold design.


One might call it appropriate that the industry’s oldest carburetor manufacturer has the longest history selling comprehensive stand-alone injection systems. Nearly 30 years after its entry into the fuel-injection market, Holley carries on in that pioneering tradition with two laptop-free, self-learning designs.

The Terminator Stealth is basically the Terminator that debuted last year but with a cover that’s pretty close to indistinguishable from a carburetor, at least when seen partly obscured by an air filter. Though not quite as versatile or handsome as the Stealth, the Sniper EFI’s proposed price point of less than a grand makes it one of the more capable units for the money. Holley brass also states that a dual-quad version is in the works.

The Holley systems will work in boost and nitrous applications; however, they require laptop configurations to do so. But they both mount with minimum work and programmed by the hand-held controller exclusively if installed as-intended: as carburetor replacements.


New for this year, Sniper EFI covers the fuel-control bases for less than $1,000. It supports as much as 600 hp, but an optional eight-injector installation gives it 1,200hp capacity.


Terminator Stealth is essentially a re-release of last year’s Terminator but with a cover that makes the unit resemble the company’s legendary double-pumper. It controls spark incident and supports boost. Though primarily module-programmed, the unit accommodates laptop programming and supports data logging.

MSD Atomic

Surely every one of us knows MSD for its multi-spark, capacitive-discharge ignition systems. But a few years ago the company diversified into the fuel side with its Atomic-series injection systems.

MSD employs the injection systems in a novel way. The injection systems are only one component in a greater CAN system. MSD offers various CAN-enabled components like an optional transmission controller that commands electronic automatic transmissions like the 4L60E. What makes this CAN system exceptional is that it updates its address list to include a very broad range of aftermarket and OEM items. If it operates on the CAN system, chances are it’ll work with the MSD Atomic system.

The Atomic system has a feature unique in the segment: it’s the only one with a CARB Executive Order (D-722), making it a California-legal install in 1987-and-older GM vehicles.


Like most others, Atomic EFI houses its ECU within the throttle body. It’s an exceptionally powerful brain at that, operating with CAN-bus technology that lets it communicate with other CAN-enabled devices. It’s also the only one in the list that comes with the fuel-delivery system. The unit alters fuel maps by user-set parameters for nitrous-oxide injection, and spark control lets it retard timing for boost applications.

Quick Fuel

In carburetor-manufacturer terms, Quick Fuel Technology entered the game relatively recently; however, seemingly overnight it earned a reputation as one of the premier performance manufacturers and tuners. In 2014, it entered the injection arena with a self-learning retrofit with a billet throttle body and a joystick-navigated controller. But in 2015 it stepped up its game with twice as many injectors, double the power potential, and an even more sophisticated color touch screen controller.


The QFI 500 model released last year relies on a one-color, joystick-navigated controller. It maintains data logging and supports optional laptop connectivity but only within a PC system (no Mac). But it has ignition-control capability, dual fan controllers, and supports boost and wet nitrous oxide installs.


QFI 8i released this year shares many of its features with FiTech Power Adder 1200 due to a collaboration by the two companies. It differs, however, by finish options; Quick Fuel offers it in Silver and Black Diamond.

FiTech Command Center

FiTech gets a special extra because it released something truly special, something that makes an injection system, regardless of brand, about as easy to install as a carburetor.

Plumbing a car is probably the most bothersome step to install a fuel-injection system. It requires mounting a high-pressure pump very close to the tank and in some cases a lift pump to prime the system (high-pressure pumps don’t self- prime). Sometimes the factory fuel line doesn’t lend itself to high-pressure operation, which requires a new line, not to mention a return line. And routing lines requires tools like tube flares and benders, good design sense for routing, fasteners and clamps, and a fair amount of time if you want to make the system work properly. And that doesn’t include dropping, boiling out, and retrofitting the tank for the return nipple. It’s a pain.

But FiTech’s Command Center eliminates every bit of that hassle. In a nutshell, it’s a reservoir with an integral fuel pump and fuel-pressure regulator that works with your vehicle’s existing fuel lines and—here’s where it gets crazy—even its engine’s mechanical fuel pump or low-pressure pumps mounted near the tank. And because it serves as its own return system, it eliminates the plumbing back to the tank. Just mount it in the engine compartment, plumb it to the throttle body or fuel rails, wire it for power, and you’re done. It’s good for as much as 850 horsepower (and honestly, how many engines make that much?). And at $395, it costs hardly more than an independent pump and plumbing—and if you ask us the price alone is worth not having to run a return line.


Don’t want to re-plumb your car for fuel lines? No problem; mount FiTech’s Command Center in your engine compartment and feed it with the existing pump that once fed your carburetor. It works with any injection system, be it aftermarket or OEM. This is a real problem solver.


Click HERE to enlarge this Fuel Injection Throttle Body Retrofit Kit Breakdown chart


Quick Fuel Technology
Bowling Green, KY 42101
Bowling Green, KY 42101
Memphis, TN 38118
Torrance, CA 90503
El Paso,
FiTech EFI



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