Best Aftermarket EFI Systems: Optimum Power and Efficient Fuel Delivery
These top aftermarket EFI systems will provide optimum power and efficient fuel delivery for your vehicle.
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BY Heather Fishel / LAST UPDATED ON May 26, 2021
Thinking about upgrading your carbureted engine to an aftermarket EFI system? Electronic fuel injection (EFI) systems are becoming increasingly popular with car enthusiasts who want better efficiency and increased power. Adding an EFI system to your car can take your engine to entirely new heights, thanks to the digital technology that takes control of the air and fuel flow through a throttle, port, or direct injection process. Thanks to their upgraded, smarter technology, these innovative systems deliver more than improved efficiency — they also give you better fuel economy, helping you fill up less often.
Worried that converting your carbureted engine to an EFI system will be too challenging? With one of the best aftermarket EFI systems, it can be a fun project. You just have to make sure you do your research and choose an EFI system that suits your car, your engine, and your needs. Whether you’re looking for an aftermarket EFI system for your passenger car, light truck, or a race engine, check out our picks for the best options right here.
This Holley 550511 EFI kit can support up to 650 HP. It comes with a handheld EFI monitor and a self-tuning ECU.
- Features an easy-to-use self-tuning system
- Includes easy-to-replace oxygen sensors
- Eliminates cold start, vapor lock, and hesitation issues
- Master kit version that comes with a complete fuel system is more expensive
- Assembling the kit requires automotive knowledge
This EFI kit comes with everything you need to maintain the classic look of your carburetor by hiding the injectors.
- Eliminates vapor lock, flooding, and cold start issues
- The more you drive, the more it adapts to your driving style
- Can be mounted wherever you want to maintain the classic look of your carburetor
- Decent mechanical abilities are required for installation.
- Doesn’t come with a fuel system
Weighing only 16.14 pounds, the MSD 2900 Atomic EFI Master kit can easily fit multiple models.
- Includes single fuel line self-tuning and built-in sensors
- There is no need for bulky ECU
- Has only eight wirings
- Laptop not needed for programming
- Battery charger needs to be plugged in for a long time
- Computer tends to drain the battery faster
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Our reviews are driven by a combination of hands-on testing, expert input, “wisdom of the crowd” assessments from actual buyers, and our own expertise. We always aim to offer genuine, accurate guides to help you find the best picks.
Benefits of Aftermarket EFI Systems
- Eliminate the need for a carburetor. Carburetors need to be adjusted mechanically to control the rate of air and fuel flow. However, they can get out of tune over time and risk failure if they aren’t constantly adjusted. EFI systems eliminate the need for a carburetor and continue to regulate the air and fuel flow independently with computations provided by the electronic control unit (ECU). This requires minimal effort on your part in adjusting the system.
- Lower fuel consumption. EFI systems are more fuel-efficient than carbureted engines. This is because the electronic system constantly adjusts the air to fuel ratio to ensure that optimal levels are delivered. Carbureted engines, on the other hand, may deliver an excess fuel to air ratio, which can lead to more fuel consumption.
- Meet the engine’s operating conditions. Your engine may have different fuel or air needs depending on the operating conditions. EFI systems can continuously monitor the operating conditions, and adjust the air to fuel ratio with respect to the ambient temperature, altitude, driving conditions, and other engine requirements such as cold starts or overrun conditions.
- Maintain optimal engine performance. Engines that use EFI systems often provide a higher torque than carbureted engines. EFI systems can optimize power, ignition timing, and air to fuel ratios across different engine speeds to promote consistent performance.
Types of EFI Systems
A single point injector or a throttle body injector has one injector mounted at the throttle body. Fuel is sprayed into the engine in rapid short bursts, which creates a buzzing noise when the engine is started. In comparison to a carburetor, this system has better cold start characteristics and is better at regulating the air to fuel mixture.
Modern EFI systems typically use a multipoint fuel injector (MPFI). It has a separate fuel injector for each cylinder that sprays fuel directly into each cylinder’s intake port. The injectors can be timed to spray at the same time to all cylinders, or to coincide with the respective cylinder’s intake stroke.
A direct fuel injector sprays fuel directly to the combustion chamber, instead of directing it to the intake valve in the case of a gas engine, or a pre-combustion chamber in the case of a diesel engine. This type of injector has a needle valve at the nozzle that’s operated with a solenoid to regulate the pressure of the fluid being delivered into the engine cylinder. Since they are installed so close to the cylinders, they are exposed to more heat and require higher-grade material that can withstand the high temperatures. This is why they are more expensive.
Holley is an automotive brand that has been making automotive fuel systems for over 100 years. It was birthed by Bradford, Penn., brothers George and Earl Holley in the late 1800s. Today, the company designs fuel pumps, intake manifolds, EFI systems, and millions of carburetors. A series of mergers throughout the years led to the absorption of other brands under its umbrella including MSD Ignition, Accel, Powerteq, and Racepak. If you would like to try out one of its products, check out the New Holley Sniper EFI Kit.
FiTech is headquartered in Riverside, Calif., and makes some of the best fuel systems. Apart from making EFI systems, it also makes fuel pumps, fuel filters, fuel pressure gauges, and regulators. The FiTech 30021 EFI System and the FiTech 30005 Easy Street EFI are some of its best EFI systems with innovative designs.
Aftermarket EFI Systems Pricing
- Under $1,000: The EFI systems within this price range are able to control injection timing according to the speed, load, and the type of driving the vehicle is experiencing. It’s possible to program them to optimize fuel consumption, especially in heavy-duty diesel engines.
- $1,000 and up: Most EFI systems are a bit on the expensive side, but that often means you are getting a reliable system that can create a program that will suit your specific application. Therefore, at this price range, you can expect to find an EFI system with a programmable control system that you can monitor and control from a separate handheld monitor.
Type of System
Like we mentioned above, there are a few different types of EFI systems — single point, multipoint, and direct. When you’re picking out an aftermarket option, it’s important to determine which type fits your car and your engine the best. Each has its own pros and cons, and the design differs between the three types. The type you choose will affect everything from the installation method to the cost of the EFI system, so make sure to consider this key detail before spending a cent.
Size or Power Output
Once you’ve settled on a type of aftermarket EFI system, it’s important to look at the size or power output of those that you’re considering. This is critical, as the size needs to suit your engine’s airflow and fuel requirements to deliver the horsepower you want (or are used to). Having a system that meets your engine’s size, power output, and horsepower will ensure you get prime performance once it’s installed. Look at the power output of an EFI system’s injector, and think about the size of your engine. Often, it’s given in a range — for example, you’ll see a max horsepower rating of 275 to 400 for a stock engine size of 250 to 400 c.i.d. or 600 to 750 horsepower for a 350 to 500 c.i.d. engine size.
Technology is one of the biggest reasons to install an aftermarket EFI system on your vehicle. These systems have become increasingly smarter in recent years, and they’re nothing like the old EFI systems that required laptops and specialized computer knowledge to get your car at peak efficiency. Today’s systems are easy to install and run with impressively easy technology. To find the best and most up-to-date options, look for EFI systems that include self-tuning capability. You can also look for systems that include handheld tuners for easy management and adjustments.
- Compatibility: Any aftermarket part you buy should be compatible with your vehicle to avoid fitting issues. The best way to get a suitable EFI system is to search for one by entering your vehicle’s year, make, and model. If for any reason that doesn’t work, try searching for your vehicle’s OEM part number, which is often indicated on the EFI system.
- Fuel: Consider the type of fuel your vehicle uses as well. Some EFI systems come with a complete fuel system consisting of a fuel pump and filters that may not work with both gas and diesel.
- Warranty: A warranty serves as proof that the EFI system was designed with high-quality materials. It will help you get a new EFI system or free services from the supplier in case the one you bought stops functioning due to defects in workmanship.
Best Aftermarket EFI Systems Reviews & Recommendations 2021
- If you are planning to use a power adder (such as a supercharger) with your EFI system, you should consider a system that is compatible with your power adder.
- If your engine is a new build, consider consulting with an engine-building professional before installing an EFI system.
- EFI systems require higher fuel pressure for efficient operation. Therefore, you should consider upgrading the fuel line to meet the EFI system requirements.
- Usually, EFI systems do not include a fuel reservoir as compared to a carburetor that has bowls for fuel storage. Therefore, you should also consider installing a fuel tank designed for EFI systems.
- The location of the fuel pump is very important because it cannot stand higher temperatures for a longer time. Make sure to mount it in a location where it can easily cool down.
Q: How does an aftermarket EFI system work?
An aftermarket EFI system uses high-pressure fuel delivery to an injector. It also uses computer controls, and overall it increases the power and fuel efficiency of a vehicle. The whole system is controlled electronically.
Q: What do I need to install an aftermarket EFI system?
You will need throttle bodies, a suitable manifold, a fuel pump with high pressure, injectors, and a filter. Apart from this, you will also need a regulator, a fuel rail kit, ECU, and a return line to the fuel cell.
Q: Do I need to use air cleaners on an EFI system?
Yes, we recommend you use cleaners. Any standard aftermarket cleaner can be used.
Q: Is an EFI system better than a carburetor?
This depends on your vehicle, your engine, and what kind of performance you’re getting right now. For anyone who wants increased power and better performance, an aftermarket EFI system can be a great upgrade over a current carbureted engine. However, if you aren’t worried about performance or power, you may not really see a huge benefit from the cost of buying and installing an EFI system.
Q: How much horsepower does an EFI system add?
The horsepower is tied to the size of your engine and power output potential of the aftermarket EFI system you buy. Typically, an EFI system will enhance your engine, but it may not directly increase your horsepower. Most aftermarket EFI systems can handle engines with anywhere from 450 to 600 horsepower, but some are suitable for as much as 1,200 horsepower.
Our pick for the best overall aftermarket EFI system is the New Holley Sniper 550511 EFI Kit because it provides a great deal of functionality.
For a budget-friendly option, you should consider the FiTech 30021 Go EFI System.