Granted, the abilities of FAST's EZ-EFI system sound very promising, skeptics will surely question how well it can really tune a motor, especially combinations with big cams. As it turns out, the system works so well that its performance warrants its own sidebar. During development testing, the FAST crew spent several hours tuning a GMPP 572 crate motor with its top-of-the-line XFI system, which netted 630 hp. FAST then replaced the XFI system with an EZ-EFI setup, and the 572 cranked out 630 hp after two pulls. "I was actually kind of embarrassed that the EZ-EFI system did in five minutes what it took me a couple of hours worth of tuning to accomplish. The ECU reacts so quickly that if you experience a lean or rich spike while cruising, you'll actually feel the motor smooth out," says David. Nonetheless, EZ-EFI does have its limits. Since it was designed as an entry-level system, David advises against using it with nitrous or boost. At that point, he recommends opting for FAST's more advanced XFI system. Even so, the limits of EZ-EFI in naturally aspirated applications is quite high, and it can easily adapt to the wildest of combinations. "We put a 227/241-at-0.050 hydraulic roller cam with a 107-degree LSA in a GMPP 350 crate motor, which had a very rough idle when it was first fired up. Within a few seconds, the EZ-EFI system made the necessary tuning changes, and the motor idled perfectly at 900 rpm."
"Most hot rodders are very familiar with a carburetor, but shy away from EFI because they're scared of the tuning process. Consequently, we wanted to develop a true self-tuning EFI system that was very versatile while requiring very little input from the user. The result is our new EZ-EFI system, which literally tunes itself within two pulls on the dyno. The kit includes a 4150-style throttle body, four 83 lb/hr injectors, fuel rails, an ECU, a wiring harness, a wideband oxygen sensor, and a hand-held controller. To keep things simple, EZ-EFI controls the fuel only, meaning that spark advance is still controlled with the distributor. Many EFI systems have the ability to make air/fuel corrections in closed-loop operation by utilizing wideband oxygen sensors. EZ-EFI takes it a step further. Instead of merely making minor corrections to the air/fuel ratio, it actually changes the base fuel map itself. For instance, if an engine needs 10 percent more fuel at a certain rpm, it changes the map instantaneously. The system is pre-programmed to achieve target air/fuel ratios of 13.5:1 at idle, 14.7:1 at cruise, and 12.8:1 at WOT. After installing EZ-EFI, the hand-held controller asks for some very basic engine specs, such as displacement, desired idle speed, and fuel pressure. The user can also change the target air/fuel ratios if necessary. After calibrating the throttle-position sensor, all you have to do is hit a button and fire up the motor. The ECU then starts calibrating the fuel map instantaneously."
"As part of the Comp Cams family that includes RHS cylinder heads and ZEX nitrous systems, FAST now has access to a diverse range of resources that enables us to develop new and innovative products more efficiently than ever before. This allows us to react quickly to changing market conditions and customer demands, and develop crossover technologies. For instance, when GM introduced variable valve timing into its LS-series motors, Comp Cams dedicated tremendous efforts into testing new camshafts for them on the dyno. It was then up to FAST to come up with the electronics to control how to advance and retard the cams. By combining our resources, Comp has developed the valvetrain components to take advantage of the Cam Phasing technology and FAST is developing the electronics to manipulate the cam phasing for maximum performance."