While you could spend a lifetime learning how to tune a carburetor, getting a car running reasonably well with one can be as simple as picking the right carb and bolting it on. Not so with fuel injection – switching a classic musclecar from carburetion to EFI is at task best left to the experts and their laptops. Or at least it was, before FAST introduced their new EZ EFI system. Now, practically anyone can experience the benefits of better gas mileage and drivability that come with fuel injection, without all the headaches. Thanks to the FAST EZ EFI’s self-tuning technology, converting a carbureted car to fuel injection, and more importantly getting it to run like you want it to, has never been easier.

EFI to Carb and Back Again

Our test mule, the “Riced Rat Rod”, is a Nissan 240SX that’s been an experimental subject on many different fronts, though it has always been powered by a carbureted 400ci small block Chevy since we started messing with it. The 240SX is a light, Tremec TKO-600-equipped vehicle that makes 425 HP to the rear wheels. Since it sees a lot of driving on the street, we figured the EZ EFI could help make this moderately-cammed Chevy a little more livable in daily driving. It seems a bit ironic that we took a factory fuel injected car to a carburetor, and then back to fuel injection, but it makes perfect sense in this case.

Along with the EZ EFI we installed a complete ignition system from Mallory. Though the EZ EFI doesn’t require an aftermarket ignition – even a stock-style distributor will work – we took the opportunity to upgrade in this area as well. We opted for the EZ EFI Master Kit that includes a fuel pump, filter, lines, fittings, wiring harness, regulator, and fuel pressure gauge. Again, you don’t need the master kit to use the EZ EFI (though it makes the installation much easier than sourcing the individual parts) but you do need a return-style high pressure fuel system – the low pressure carbureted counterpart won’t cut it.


Here's our carbureted 400ci small block Chevy before the EZ EFI swap.

The first part is getting the new FAST throttle body installed. It utilizes all the same mounting points as a 4150-style 4-barrel carburetor, so even the throttle return spring is a direct fit. All of the electrical connections are labeled, and the majority of them plug directly into the throttle body. The wide-band O2 sensor that allows the EZ EFI system to tune itself goes in the header collector, but since we already had the FAST Budget Wide Band system installed (which uses the same kind of sensor) we only had to plug the EFI connector in. The other external sensor is for coolant temperature, which we installed in the intake manifold next to the water neck and opposite of our Auto Meter water temperature sensor.


The FAST throttle body bolts on just like a carburetor, though the wiring harness for the injectors, throttle position sensor, and intake air temperature sensor has to be plugged in as well. External connections for power, coolant temperature, the wideband O2 sensor, and RPM signal complete the wiring for the EZ EFI system.

The wiring is extremely simple. Heavy-gauge black and red wires for power and ground must be routed directly to the battery to avoid any electrical noise problems. As we said before, the Master Kit includes a plug-and-play fuel pump relay harness that snaps into place and only requires a power wire connected to the fuel pump. The RPM input is one of the most important sensors and hooks directly to your ignition box output, or there is a signal converter for HEI-equipped vehicles included with the kit. All that is left is the serial cable plug for the display, the display power connection, and a wire to a 12 volt switched source that will turn the ECU on. There are also ground circuit provisions for A/C-equipped cars to raise your idle speed when the compressor is running, and an electric fan control with an adjustable activation temperature controlled by the ECU.

Chevrolet Big Block EFI System for the 427, 454, 502 and Other Chevrolet Big Block Engines



System includes:
•Four barrel single plane Edelbrock Victor Jr intake manifold.


•Our own custom 1000 CFM 4 bbl throttle body. It features all aluminum and stainless steel construction, sealed ball bearings on the throttle shafts, and progressive linkage. Comes complete with idle control motor and throttle position sensor. This is absolutely the finest 4 bbl throttle body on the market!


•Jumbo fuel rails and mounts. Rails have 9/16" diameter bores providing excellent flow and dampening characteristics.


•Our custom compact high flow patented mass air meter. The air meter is concealed within the air cleaner of your choice to maintain the vintage look! Systems are also available with our patented Pro-M mass air meters for draw through or blow through application.


•Complete production quality wiring harness. This stand alone high quality harness allows easy installation of our EFI system into any vehicle without connecting to your existing harness. For ease of installation each harness connector is individually labeled.


•Production mass air sequential electronic fuel injection computer.


•Eight high quality fuel injectors, sized to your application. The injectors are sized to allow ample room for large increases in horsepower. These fuel injectors are held to much closer tolerance than typical production injectors.


•All needed sensors. Most of the sensors are mounted right on the injection system for a simple install. No crank sensor to complicate the process!


•High performance billet aluminum distributor complete with ignition module, rotor and cap. Our entire ignition system is contained within the distributor and ECM. Just install the distributor and plug it into the harness. No spark boxes needed. However, after market capacitive discharge ignition systems, boost retard systems, nitrous control systems, rev limiters and shift lights can all easily be added.


•High performance coil featuring faster rise time and increased spark duration for increased performance. This coil comes with heat sink and mounting bracket.


•Throttle body base gasket, throttle cable bracket, assorted hardware and fittings and detailed instructions for a simple turn key installation.
All of these components are absolutely the best quality available. Unlike the competition, we will never sell you something that is "good enough" just because it costs less to produce.

Why Our System?
. . . Here's why!

Don't settle for empty promises, GET REAL RESULTS! The other companies make it sound as if it's a benefit to have the ability to "tune" their systems. It's NOT a benefit... IT'S A HASSLE! The reality is, programmable speed density EFI systems are not much more efficient than a 4 bbl carburetor. You're punching keys on a computer, rather than turning screws and changing jets and springs in a carburetor. The end result is an expensive system, that cost almost as much money to get tuned properly as the initial cost of the system. And where is the advantage? They require constant laptop fiddling to keep running properly. You could have gotten that with a carburetor! They are a little more efficient than a carburetor, but not enough to justify the cost. The only thing worse than a programmable speed density system, (besides a carburetor), is a NON-programmable speed density system. Non-programmable speed density systems only work on bone stock or specific applications. Non-programmable (or non user-programmable) systems are factory calibrated to a specific engine, with a specific combination of parts. They have no provision to account for variances such as engine modifications (even minor ones!), vehicle specifics, or atmospheric conditions. The result is, they just do not work very well.

The latest thing being offered by the competition is the "self tuning" speed density EFI system. They claim that their system will tune itself while driving. This is very misleading. These systems DO need to be programmed by the installer, so don't be fooled by their careful use of words. They are far from "self tuning". These systems require you to tell the computer what air/fuel ratio you want under any certain set of circumstances. Keep in mind that the real benefit of a good EFI system is all the knowledge that you buy with it. Our computer comes with all the programing done for you. With our system, you get the benefit of thousands of man hours spent by the OEM fine tuning the processor. It is simply not practical for you, or a dyno shop, to even attempt to duplicate the expertise you get pre-programmed into our processor. Even if you spent months attempting to perfect your tune with one of the "self tuning" systems, it still would not nearly compare to what we give you with our system. Quite honestly, if you're thinking about buying one of the other EFI systems, just save your money and buy a carburetor. Their "self tuning" systems do not offer enough benefit to justify the cost.

In addition, many of the competitors EFI systems are "throttle body" systems. While these may offer some ease of installation, the benefits over a carburetor are minimal. Throttle body systems are not nearly as efficient as our Sequential Port Fuel Injection system. For more information on throttle body vs. port CFI, please see our Q&A page.

Our MASS AIR system does it all for you, and provides REAL PERFORMANCE BENEFITS over a carburetor or speed density system. It is by far the most user-friendly and most effective aftermarket fuel injection system on the market. Get improved power and torque as well as improved fuel economy, performance and reliability. Unlike programmable speed density systems, you will never need to tune this system. No laptop, no hand-held programmer, no tuning or tweeking, no dyno! This saves you the hassle and expense of tuning and trips to the dyno. When it comes time to make further engine mods, chances are you will not need to change a thing on our system. If you plan to make LARGE gains in horsepower, and you need to change your injector size, just return the computer, and we will recalibrate it for you, rather than retuning, reprogramming, and more trips to the dyno. Our system is even easier to use than a carburetor. You need to tune a carburetor. With our system, you just install it, and you're done!

Edelbrock's Torker II intake manifolds feature a single-plane, low-rise design that can give you top-end horsepower without affecting the mid-range. What Edelbrock did was increase the plenum volume and alter the short-side radius of the runners, to give the air/fuel charge a straight shot at the intake valves. That straight shot produces a potent power build from 2,500 to 6,500 rpm.