While carburetors certainly have their virtues in terms of period-correctness and the unique road manners they provide – along with the ability to deliver a whole lot of fuel in quick fashion in competition setups – it’s hard to argue with the fact that a fuel injection system makes a car much easier to live with on a day-to-day basis.
Dialing in carburetors is a fine art, and not one that many can do properly. Moreover, while a certain tune might be totally dialed in one day, changes in temperature or engine setup can completely throw things off, and there’s always that feeling that a carb is never “perfectly” in tune.
In this article we’ll be showing you how bolt up FAST’s latest EFI system, EZ Fuel (PN. 30227-06KIT) to show how making the transition from carburetion to fuel injection is simpler than ever – and how you can drivability, fuel economy and horsepower gains in the process.
While a carburetor contends with the air and fuel mixture based on a number of mechanical adjustments – which must be tweaked regularly for a multitude of external factors – modern fuel injection systems use software to analyze the situation on a constant basis, making real-time adjustments to the mixture whenever required without the need for you to get under the hood to investigate the situation.
That sort of reliability goes a long way when you’re about to cold start your ride at the crack of dawn on the day of the car show, or when you’re about to make an impromptu wide-open-throttle run on some back road.
It’s that rationale that helped Cameron Prause, whose father is the owner of this clean ’55 Bel Air, arrive at the conclusion that it was time to make the switch, some 20 years after acquiring the car.
“We got the car at the Ponoma Swap Meet back in 1996,” Prause explains. “It was straight out of a barn – full of bullet holes – and it was a four-year project for my dad and I. We’ve got a few other projects, but this one is definitely our favorite.”
This Bel Air is powered by a 383ci small-block V8 that formerly saw air and fuel delivery from a 650 cfm carburetor. It was slightly warmed over with a set of headers and an Edelbrock intake manifold, and was putting out close to 450 horsepower. The car was built to be a cruiser with an attitude, making it a perfect candidate for the FAST EZ Fuel conversion.
The Latest Tech
FAST EZ Fuel vs EZ-EFI
- New touchscreen interface
- Throttle body is now powdercoated die cast aluminum
- Crossover line now built into the throttle body itself
- Additional tuning adjustment parameters
- More durable, heat-resistant wiring harness construction
- Tuner powered through wiring harness instead of an external power source
For the ease of simplicity, and because the hardware can handle up to 650 horsepower – which is plenty of headroom for this particular Chevy 383i V8 – we opted for the throttle body injection kit with an inline fuel pump.
The new throttle body mounts up right where the carburetor lived, taking up about the same space under hood and allowing for the existing air cleaner to be used, which in turn keeps the motor’s clean aesthetic intact.
This self-tuning setup takes the guesswork and hassle out of installing an EFI setup on vintage cars as it does not require a laptop or intimate knowledge of tuning software in order to get the system up and running properly.
The Difference Between FAST’S EZ Fuel Vs. EZ EFI System
FAST’s EZ Fuel system has nearly all of the required sensors built into the throttle body housing itself, with the exception of the O2 sensor and coolant temperature sensor. Not to be confused with its predecessor, the FAST EZ-EFI system, this new system sports a few key updates, including a new, full-color, touchscreen-based handheld interface and some material upgrades to the throttle body itself.
“The throttle body is now a powder-coated die cast piece, which is a nice upgrade in and of itself,” says FAST’s Matt Maxwell. “Also, the old system had an external crossover line, whereas the new one has this built into the throttle body itself, which cleans up the look a bit.” It also has some functional upgrades as well, like an internal pulsation dampener, which acts like an accumulator to ensure the fuel supply into the injector remains consistent.
Before you even take the new setup on its first shakedown run, the new system’s input method will prove to be an appreciated upgrade over the previous button-based version. “The EZ Fuel system now also incorporates a new touchscreen handheld interface,” says FAST’s David Page. “While it’s a lot more attractive and easier to navigate, it also has several user-configurable dashes for viewing engine and system information, as well as a master dash that shows all engine and system data on one screen.”
The new touch-screen also allows more adjustments to acceleration enrichment, cold starting fuel, and hot starting fuel. -David Page, FAST
The fuel injection system’s external, weather-sealed ECU offers the ability to mount it wherever you want – out of the way in the engine bay, under the dash, etc., as long as it’s a safe distance away from heat sources like exhaust headers. The box has built-in indicator lights that provide system status to make troubleshooting easier, so it’s a good idea to make sure you mount it somewhere where those lights are still visible.
Along with the other upgrades versus the previous version of the EZ Fuel EFI system, the new kit uses the data connection to pull power for the touchscreen interface directly from the wiring harness rather than requiring a secondary cigarette lighter power source. It’s one of those things that might seem trivial on paper, but can make a big difference when you’re actually out there working on the car.
Making The Switch
Once we got the old hardware off, the new throttle body drops into place looking right at home in the same spot. Along with the external ECU, the system also utilizes an external fuel pressure regulator, so you’ll want to scope out an easily accessed and viewable spot to mount this piece as well.
While FAST offers the kit in both in-tank and inline fuel pump flavors, we decided to go with the inline system for the sake of simplicity – using an externally mounted fuel pump might result in a bit more noise, but it does have the inherent advantage of easy access from its mounting point along the frame rail of the car, and it also prevents us from needing to drop the fuel tank in order to perform the upgrade – or replace it with a tank designed specifically for use with EFI systems.
It’s also important to note that if your garage is not equipped to do exhaust modifications, you should swing by an exhaust shop before digging into the install in order to get the oxygen sensor bung welded in beforehand. The kit includes a plug so that you can cap off the sensor and remove it later once the rest of the system is ready to be installed. It’s also important to note that it is critical that the exhaust system is free of any leaks so that the EFI’s computer can read accurate data from the oxygen sensor once everything is buttoned up.
We also needed a power source in order to feed power to the new electronics, so the system’s main power and main ground needed to be hooked up directly to the battery. It’s not recommended to daisy chain this system to another power lead, as it’s important to avoid any electrical interface between the EFI system and the battery itself.
With everything hooked up, the next step is to get the touchscreen interface connected to the ECU and calibrate the system. This handheld device eliminates the need to add a laptop to the mix or other external ways of talking to the system, and the set-up wizard collects some basic data about the motor and automatically tunes itself accordingly.
The first time you turn the engine over, the interface will provide some feedback about what it’s doing as it learns the proper fuel mapping for the motor, and from there you’ll head out on the road to put the car through part-throttle, full throttle and idling situations in order to help the system sort out the ideal calibration.
The system will quickly lock in on a solid baseline, but will continue to fine-tune parameters every time you drive it based on current conditions. That’s one of the key benefits of an EFI system over a carbureted one, as you’d be doing those adjustments with hand tools under the hood otherwise and hoping for the best.
As we’ve mentioned in the past, we don’t expect big horsepower gains from converting to an EFI system. Any gains that we see are there because of the lack of a proper tune on the carburetor, rather than an increase because of the EFI. But what the EZ Fuel system does promise is exactly what we ended up with.
Cameron has reported back to us that he finds the car much easier to start these days, especially on colder mornings. The idle is much smoother now that the fuel is more controlled, and the throttle response is far better, giving him exactly what he intended when the car was built. There is one other feature to the EFI that Cameron has noticed, and that is that the fuel smell is gone from the engine compartment now, and that means a much cleaner smell in the interior of the old beauty.
And that, of course, is the beauty of electronic fuel injection – you’ll spend less time wrenching and testing and more time out there on the road enjoying your car. And, no matter how much experience you have tuning carbs, it’s doubtful you’ll be able to dial in the setup on the same level that EZ Fuel’s ECU can.
Visit the FAST website for more information on EFI conversion kits for both street and track performance, and get in touch with the FAST staff for any questions about which system is best for your specific application.