The Evolution of EFI

Nov 22, 2009

Fuel injection has been around longer than most of the motoring public realizes. From early British experiments in 1889 by Frederick W. Lanchester to E.J. Pennington’s 1896 U.S. patent for a motorcycle outfitted with it, fuel injection has been encroaching on carburetor territory for more than 100 years.

First used commercially on diesel engines in the 1920s because it was discovered to resist G-forces, fuel injection was adapted for use on WWII aircraft two decades later. Later still, Bosch developed a mechanical fuel injection system that was incorporated on the Mercedes-Benz 300 SL in 1955 and modified for use on Porsches as early as 1969. Because it produced power, good throttle response and reliability, it was used on Porsche racecars through the 1980s, where its deficiencies-poor fuel economy and emissions-were irrelevant.

Chevrolet offered a mechanical fuel injection option with its V8 engine in 1957. The constant flow port injection system produced about 290 horsepower. Throughout the 1960s, various mechanical injection systems continued to be used on V8s and in racing, despite the 1957 introduction of the first commercial electronic fuel injection system, the Electrojector, by Bendix Corporation. Promised at $395 on the AMC Rambler Rebel muscle car, it demonstrated so many problems, EFI didn’t actually make it past pre-production until 1958 when the Chrysler 300D and DeSoto Adventurer claimed the title of first series-production cars equipped with a throttle body EFI system. Unfortunately, most were later retrofitted with four-barrel carburetors due to performance issues.

Conquering its teething problems, closed loop EFI became the answer to progressively restrictive emissions regulations that required fuel metering precision and accuracy. Now facing even stricter emissions requirements, today’s systems are accurate, reliable, low-maintenance and cost-effective, providing cleaner exhaust emissions and more engine efficiency. Once prone to diagnostic disparity, current EFI systems are easy to diagnose and typically require less maintenance than traditional carburetors, which must be adjusted for altitude or seasonal changes.

The Next Level

But the realm of EFI is not static; changes continue to occur with ongoing technological development. Brad Cauzillo, marketing manager with Kinsler of Troy, Mich., lists several advances: more user-friendly software and ECUs with dual-wide band sensing and data-logging capabilities that provide more precise information; large inside diameter fuel rails to reduce pressure pulses; accurate system pressure control; high-flow throttle bodies; and manifolds made for easier EFI component installation.

Elie Nahed, sales manager and EMIC (engine management installation centers) program manager for ACCEL DFI says, “Tuning an OEM ECU is difficult, more complicated. There are parameters that can’t be manipulated.” Therefore, many consumers turn to aftermarket systems like our affordable Thruster EFI Engine Management System. We also offer complete Plug & Play systems for consumers who are starting from scratch. “Everyone wants a complete, easy-to-install system for their car, whether it is for early or late model engines, a kit makes the job easier.”

Kits are convenient, but including everything can get costly, according to Joe Pando, fuel injection manager for MSD, El Paso, Texas. “We considered including adapters in the kits, but then the price goes up.” The problem, he says, is that many USB devices are not compatible. “Laptops come with adapters, but you have to get the right one. We call it ‘USB plug-and-pray.’ Once you get the right connection, it’s easy,” he says, but despite listing compatible adapters in the instructions, “most of our tech time is spent connecting computers, not dealing with software questions. The jobber just sells the product. When the end user has connection problems, we’re the missing link, helping jobbers answer their questions.”

To resolve this problem, MSD is developing a proprietary USB adapter, due out later this year. That’s in line with their MEFI system, developed by GM using quality parts and intuitive, easy-to-use software. “People are more comfortable with EFI, but they don’t have a lot of knowledge about computer systems. This is intuitive; the software is easy-”it doesn’t ask for a lot of technical information. It has pictures in the instructions and point-and-click simplicity. Point-and-click is the trend. It’s easy to use, which is what people want.”

The one thing people want as much as “easy” is “affordable”, and that is another aspect MSD is working on. “We have two basic systems: the MEFI and the Blaster EFI, tuned for racing, not the street, for those who want maximum power. Most companies have a single system they try to use in both arenas. But both require different finesse, so we’ve developed a product at a cheaper retail price, separate from the high-end. Motech costs tens of thousands; entry level is in the thousand range for a different market.”

“Cost is still an issue,” TJ Tracey, partner at Motorvation in Memphis, Tenn., recognizes. “Over the years, people have come to believe in fuel injection, especially in the racing world. It has proven itself. People aren’t afraid of computers any more.” But some are afraid of the cost. That’s why Motorvation is working on building a system to lower the cost so it’s not much more expensive than a carburetor. “We’re filling a void for people who have been scared of EFI, and we’re dropping the price,” Tracey continues. In addition, “Our ECU is a simple unit, but we’re coming out with an advanced unit by summer for guys who want to go to the next level.”

On the Mark(et)

Whatever the level, simplicity is important. Motorvation introduced its new Motorvator EFI at PRI in 2007. With a simple software package tailored for drag racing or street rodders, it cuts costs and the work load. Tracey explains how it works: “You pull the carburetor and use the existing manifold, just slide the carburetor up, slide the throttle body down. The injectors are built into the throttle body.” He believes the system’s simplicity will sell it. “Most systems are too complicated for the weekend rodder or racer. We use terminology they understand. It’s a simple setup. We even do the base tune-up for new customers; they fine-tune it; it’s easier.”

Easy is the name of the game. Motorvation offers complete kits with fuel pump, regulators, electronics, sensors and wiring harness. “Just add labor, fuel lines and fittings!” Parts are also sold individually for customers who, “have EFI and are changing from an OEM computer to ours or want injectors in the intake like standard EFI systems-¦” Tracey explains. “It runs identical, only you lose the ability to individually tune each cylinder.”

Accel DFI also has a new Thruster EFI program for jobbers. “It’s an affordable, entry-level engine management system,” Nahed explains, “Designed for the masses, from 200 horsepower to 1,400 horsepower applications. The software is loaded with EFI base calibrations for most GM crate engines and numerous other calibrations that are designated by engine size and horsepower.” Both the Spark Fuel and Plug-and-Play EFI kits are easy to use and are fully upgradeable to a Pro version later down the line. “No need to change the wire harness to upgrade; just send the ECU in to us,” Nahed says. “The new Thruster’s limitations lie not in horsepower, but in all-out bells and whistles. For example, unlike in the Pro version that offers three stages of nitrous. The Thruster offers one stage only.”

Today’s consumers are not only looking for max horsepower, they want to maximize fuel economy as well.

“They’re converting from carburetors and installing EFI plug-and-play systems like our Thruster kits on their crate engines. With gas at $3-plus a gallon,” Nahed states, “You’re better off going with EFI. In some instances, the system pays for itself within a year, depending on how often you drive the vehicle. It’s economical; if you switch the camshaft, you have to reconfigure the carburetor or buy a new one. That can cost over $600. With Thruster EFI, you just fine-tune the engine.” Accel DFI Plug & Play packages are fully upgradeable to any engine combination. “For the racecar fanatics, Accel DFI’s Gen 7 has remained popular for years. Nahed says, “It offers up to 144 screens of tuning and diagnostics. It has four separate air/fuel tables and can run four injectors per cylinder. It is only sold through our EMIC Dealer network.”

Both Thruster and Gen 7 systems can be ordered with a Standard O2 or a Wide Band O2 that includes a DATA Logger.

Cauzillo says most of the EFI brands Kinsler sells now offer dual-wide band O2 sensing capability for engines with two exhaust collectors. “Data logging allows the user to monitor O2, MAP, TPS, rpm, coolant temperature, etc., then save the information while running the engine and upload it to their laptop for diagnosis.”

Like Accel DFI, MSD also does a lot of conversions through its dealer network. The company also provides EFI for crate motors for GM, and Pando says, “Ford and Chrysler are coming this year. Late model crate motors are easier, cheaper and more reliable and can be put in a Camaro, a street rod, a sand car. It’s easy to make a lot of power with a new engine, especially the light all-aluminum engines.”

But increased power has a dark side: emissions. As Pando observes, “Emissions is a big deal. There’s a lot of scrutiny by the EPA, especially of the sand car, which is popular in California and Arizona. That’s a huge niche market, and it’s under the microscope.” That’s why MSD, in conjunction with GM, is developing one of the first emissions-legal aftermarket EFI systems. “If we provide a certified system, it’s more appealing. Sure, it’s costly, but it will pay off.” Pando sees acquiring emissions-legal certification as this year’s benchmark.

Regulation may quell Nahed’s concern that emissions can be, “tuned out of a vehicle because you have full control over the ECM with a laptop.” The introduction of new products to assist in emissions-compliant operation will also help. The Aeromotive Digital FMU has filled a need in return-less fuel systems by offering the ability to control a secondary fuel pump necessary to provide the additional fuel needed in forced induction EFI applications while still retaining the emissions-friendly, return-less fuel system.

Aeromotive is focused on the fuel delivery side of EFI, manufacturing fuel pumps, fuel pressure regulators, filters, EFI adapter fittings, fuel rails and accessories such as the Pump Speed Controller and Digital FMU. “As an engineering-driven company,” says Fickler, “we focus on developing solutions to problems that exist in the market.” They have more than 30 fuel pumps and 30 fuel pressure regulators developed for specific applications.

However, because it’s easy in EFI applications for consumers to mismatch components and create a fuel system that is more a collection of mismatched components than a system, Aeromotive offers dozens of complete systems to keep it simple.

Due to the popularity of crate engine EFI combinations in the street rod and muscle car markets, Fickler claims that Aeromotive’s new EFI-style quick-connect adapter fittings are in high demand as builders adapt from OE fuel rails to AN style plumbing for the rest of the project.

One innovation at Kinsler is a new 12AN fuel rail I that’s 0.970″ I.D. to reduce fuel pressure pulsations caused when large injectors open and close. “Our K-140 pressure relief valve will handle 1,000 lbs/hr with ease, maintaining a constant rail pressure, yet it is extremely accurate with only 100 lbs/hr flowing through it,” he boasts, adding that all Kinsler fuel injection manifolds are designed to accept EFI components, some with multiple injectors per cylinder.

As performance levels increase, Fickler speculates that many builders will opt for the billet fuel rail kits and systems offered by Aeromotive for the popular LS Series engines (1, 2, 6 and 7), all of the popular Ford EFI V-8s, including the Mod-motor, and the Chrysler Hemi.

Race on Sunday…

Performance levels do continue to rise, thanks in part to weekends at the race track. Pando says the, “Win-on-Sunday, sell-on-Monday tradition is still alive.” Although racing is a large portion of their business, MSD is, “constantly developing new products” for all markets, but, “by working with racers, we can simplify the technology for the street market.”

Fickler believes that much of the market is still paranoid about the “black box,” but as more cars adapt EFI technology and more EFI cars win races, “The paranoia evaporates.” Ironically, he notes, “Old-school carbureted guys make the best EFI salesmen when they realize the potential of EFI and how racer-friendly the technology has become.”

Credited by Fickler as the real pioneer in this area, Motorvation’s Tracey won the inaugural Million Dollar Drag Race with an EFI combination against hundreds of carbureted racecars. Others have followed. Through it all, “the Aeromotive A1000 is still the standard bearer in the EFI aftermarket,” he claims. “Capable of supporting up to 800 horsepower in a forced induction EFI application with 125,000-mile continuous duty durability, the pump offers racecar performance with OE reliability.”

“The Eliminator, offering about 20 percent more flow than the A1000, has been very strong as horsepower levels in the EFI aftermarket continue to climb,” Fickler continues. He says the market is defined by high-horsepower EFI tuners that will run one of their inline fuel pumps such as the Eliminator, Pro Series or Belt Drive Mechanical Pump combinations with horsepower levels exceeding 2,500. “A milestone in the belt drive EFI market was the introduction of our tall-top Ultra-high Flow EFI Regulator. Designed for belt drive systems, it has demonstrated the ability to data graph well, while eliminating the disadvantages of extremely high current draw and weight. Of course, our Belt-drive fuel pump combinations offer unmatched fuel flow and control for the ‘lunatic fringe.'”

Whether or not they’re “lunatic,” many customers are racing on the fringe. For them, Kinsler manufactures billet aluminum throttle bodies designed to last a long time in harsh environments. The throttle shaft bores are rifle-drilled, then bronze-bushed. The throttles are final-bored, giving a perfect round sealing surface for the throttle plate. The throttle shafts are made from a very tough steel alloy, then milled on both sides for high air flow. They are chrome plated for long life. Cauzillo proclaims the progressive linkage and virtually any TPS mounting on this throttle body, “ideal for any racing use.”

Fickler claims there are very few markets that do not have some level of EFI penetration. “Aeromotive has experienced growth in every aspect of the EFI market from micro-sprint combinations that produce 200 horsepower to 3,000 horsepower Pro-Mod style drag race cars.” While he feels that much of the focus on EFI has been on drag racing due to the power levels and subsequent need to deliver enormous amounts of fuel, he contends that off-road, road racing, street rod, sand sport, sport compact, mini-sprint, marine and the recreational performance enthusiasts have all experienced measurable EFI growth in recent years. “Unlike many manufacturers, we are seeing significant growth in the sport compact market. As that market matures into a true performance market and away from the cosmetic accessories that defined much of the market’s earlier growth, we see horsepower levels that require the same fuel system more commonly found on high-horsepower V-8s.”

As Fickler revealed, Motorvation is staffed by drag racers. Tracey confesses that, “drag is what we focus on because it’s in our hearts. We are racers and users of these systems. It helps our credibility. Other systems are built by engineers who aren’t users. We’re available at many of the NHRA drag races to answer questions and sell products.” No one better knows the benefits of EFI within that market. “With drag racing, the cost of racing fuel is $10-12/gallon. Rumor has it methanol is going to $5-6/gallon. EFI burns less, sometimes half as much as other systems. You can save hundreds or thousands in fuel costs. That’s a selling point.”

But no matter how focused they are on racing, Tracey understands that Motorvation’s customer base is a mix and that the, “street rodder market is huge.” He knows they’re looking for drivability and that, “EFI is second to none for that.” But he wasn’t fully aware of other possibilities until recently. “PRI opened us to new markets: off-roading, rock crawlers, guys who play in mud, Baja, arena, etc. Those are vehicles that take abuse. The float level in the carburetor doesn’t work well in those conditions.”

Perhaps the largest new market, however, is the marine industry. “They’re building 600-inch torque motors. Their carburetors are getting fuel slosh and burning up the motors when in a lean condition. It’s a safety factor for both those markets.”

Education is the Road to a Secure Future

While the manufacturers are learning about new markets for EFI, they also must work on educating all markets. As Pando points out, there’s more information about it available now, including websites like and classes to certify jobbers and installers.

“You can learn with a tutor, get online help or take classes,” Nahed elaborates. Accel DFI offers four classes a year. “Like anything electronic, it can be frustrating, but once you learn how to do it, the complications go away.”

However you learn, Nahed believes it’s important to do so. “The future is fuel injection. Lots of countries don’t allow carburetors anymore.” He lists several benefits of Thruster EFI vs. the carburetor:

  • Easier start in all weather
  • Better idle control
  • Improved acceleration and throttle response
  • Improved fuel economy-up to 25 percent on cars
  • Reduced emissions
  • Increased horsepower and torque
  • No more rejetting of carbs when the weather changes
  • Ability to switch from gas to E85 on the fly

“People want a street-able car,” he continues. “Whether it makes 300 horsepower or 1,000 horsepower, they want to drive it. Gone are the days when all they did was to put it in a car show on weekends. Fuel injection is the only way to get a radical car drivable.”

EFI is a great tool to have control of your tuning. Tracey advocates letting the customer know, “This is not new stuff; it’s old technology that’s proven. There’s nothing to be scared of. They aren’t guinea pigs.” He believes acceptance of EFI has been slow because of the expense and fear, but says all that has changed and it’s time to let the market know.

If the customer needs more than information, Motor-vation will help. “We’re tuning our systems on the front end so it’s 90-percent finished.” Motorvation makes EFI simple for the end user, but also assists the retailer. “Our products are price-structured for the WD and jobbers and engine builders, who are 90 percent of our business,” Tracey reveals. They’ll even drop-ship the system. “We offer endless support. We do everything up front so there’s less follow-up needed. Everything’s labeled with thorough instructions; it’s idiot-proof.”

Nevertheless, until the jobber is up to speed, he can call with the customer’s information and Motorvation will recommend what parts to put together in the kits. “We customize kits per engine,” Tracey explains. “Most kits are standard, but some may need a larger pump or injector. Most importantly, you need the right combination of parts. Our kits have four horsepower levels. We tell our customers, ‘up to this horsepower level, use this part number.’ Jobbers can look that up.” He mentions that kit prices fluctuate with injector size, but says Motorvation takes the loss internally so kits remain the same price to the jobber.

That kind of security is important, Tracey believes. Industry security is also important, and he sees plenty of it. “There have been small changes [in fuel injection] over the years-improvements in electronics. They continue to build computers smaller and faster for less money.” However, he reassures, if you buy a system today, there’s no need to change in two or three years. “There are always software or firmware upgrades that can accomplish needed changes.”

Security about the product aside, Fickler believes there still exists a need to simplify. “I think companies such as Motorvation, MSD and FAST have taken the lead in trying to give the market a product that eliminates the ‘black box’ paranoia.”

However, to achieve successful sales of EFI components, retailers must alleviate the customer’s concern about the technology. The successful EFI retailer must have a good working knowledge of the various aftermarket ECUs, their strengths and weaknesses.


From a novelty option in the 1950s to more practical applications through the next few decades, EFI has become a mainstay in the automotive industry. “People are more comfortable with fuel injection,” Pando reiterates. “Eight to 10 years ago, it was still a big mystery; today, every car has it. If you want your streetrod to start and drive like a Mercedes, you have to have fuel injection.”