Most of us with classic Chevys strive to upgrade our rides for the street. We ditch drum brakes for discs, bolt in overdrive transmissions, add air conditioning, and perform a plethora of other upgrades with one goal in mind: better street manners. We've gotten used to modern cars and while we still dig the timeless lines and "soul" of our older cars, we also appreciate the technological advances of the last 40 years. One of the biggest advances in terms of drivability is electronic fuel injection, more commonly referred to as EFI.
Until recently, the only downside to slapping an EFI system into a classic Chevy was complexity, and to some degree, cost. Typically, the intake manifold had to be modified to accept fuel injectors or outright replaced. The tuning systems were complicated and either required a laptop or "one size fits most" programming. FAST saw an opening in the market for a simple to install kit and developed its EZ-EFI system. Unlike its more robust systems, like the XFI line, EZ-EFI is geared towards the "average Joe" who is more concerned with making his ride nicer to drive on the street and cruise down the highway than building a racecar.
To get the price and complexity down, the EZ-EFI system was designed to use an existing 4150-style intake manifold. The four fuel injectors are integrated into the throttle body so there's no need to buy a new intake or modify an existing one. In fact you can even use your current carb-style air cleaner. The downside to this is that with only four fuel injectors the EZ-EFI isn't really suited for engines that put out over 550 hp. Then again, contrary to what you may read on the internet, the vast majority of cars out there make under 500 ponies.
There are several features built into the EZ-EFI system to improve drivability. The key one is what FAST calls "adaptive learning." This in essence lets the system tune itself and anyone who has messed with a more complicated EFI system can certainly see the benefits. The system also has a "pre-squirt" feature that helps starting by injecting a small amount of fuel into the manifold at key-on. We found the result of this to be that our big-block fired up at the push of a button, just like a modern LS engine.
So, what this new system is all about is drivability and ease of install. To put the EZ-EFI to the test we decided to find a carbureted engine and see how easy it was to put on the FAST system and get it running good. Doing this on an engine dyno would give us better control and allow us see what the real world results would be. After all, the "butt-o-meter" is only so accurate.
Purely out of curiosity, we decided to also try a bigger carb on the engine. In this case the 1,000 cfm Holley HP that was on the engine when we bolted it to the dyno. It put down 531 lbs-ft at 3,900 rpm and 516 hp at 5,600 rpm. About the same torque as the EFI system, but 20 more peak horsepower. The down side would be that the 1,000 cfm carb sucks fuel like it's going out of style compared to the EZ-EFI. There's also a chance that over time, with more WOT "driving," the adaptive learning function would further fine tune the EFI system and raise our peak numbers a bit, but most likely not up to the numbers put down by the monster Holley carb. But for a street car that spends most of its life under 5,000 rpm, the EZ-EFI system offers performance on par with a traditional carb with drivability that the carburetor can't come close to. Best of all, it really was easy to install.