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. Here's our baseline engine, a 454 big-block with RHS heads and a middle-of-the-road camshaft. It's one of Westech Performance's test mules so it was perfect for this exercise. Normally it makes less than 550 hp, well under the EZ-EFI's performance ceiling. Here's our baseline engine, a 454 big-block with RHS heads and a middle-of-the-road camsha 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. Here's the main player in the FAST EZ-EFI kit, the throttle body. One key to it carrying the "EZ" moniker is that the four fuel injectors and most of the sensors are all integrated into the throttle body. It's also compatible with any standard carb-style air cleaner, so you can keep that "old school" look. Here's the main player in the FAST EZ-EFI kit, the throttle body. One key to it carrying t 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. On the back of the throttle body is the Idle air control motor along with two of the fuel injectors. The base of the throttle body also houses three manifold vacuum ports, and there's one ported vacuum port on the body near the air temperature sensor. FAST really worked hard to make the unit as compact and unobtrusive as possible. On the back of the throttle body is the Idle air control motor along with two of the fuel Since the throttle body is designed to replace any carburetor that works on a 4150 square-flange manifold, it was a no brainer for FAST to make the unit accept any Holley-style throttle linkage. Just like a carb, you'll want to make sure to use a throttle return spring or two. Also, just below the braided crossover fuel line is the TPS idle re-calibration screw. Since the throttle body is designed to replace any carburetor that works on a 4150 square- On the passenger side of the unit, there's the air temp sensor and the throttle position sensor. On the passenger side of the unit, there's the air temp sensor and the throttle position s 1 | 2 | » | View Full Article By Steven Rupp Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!