Rick Anderson: One of the big advantages of a Holley stand-alone EFI system over a stock GM computer is that you’re working with a system that will grow with your needs regardless of how radical an engine combination might get. The combination of the self-learn feature and the speed-density air metering makes the system much more user friendly once you perform more extensive engine modifications in the future. Getting your motor up and running for the first time is extremely easy even if you don’t have any experience tuning EFI. Holley has many baseline tunes, ranging from stock motors to 1,000hp turbo combinations; you can download off of our website. This helps immensely in getting the motor started, and then the self-learning software will tune the air/fuel mixture from there. Holley offers two stand-alone computers for LS motors, the HP and Dominator systems. The HP system comes with the computer, wiring harness, wideband O2 sensors, and tuning software. It features controls for up to 16 low- or high-impedance fuel injectors, internal data logging, four-stage nitrous control, boost and water injection control, fuel and spark control for individual cylinders, and a one- to five-Bar MAP sensor. Furthermore, it is compatible with both 24- and 58-tooth reluctor wheels. In addition to having all the same capabilities of the HP system, the Dominator system can control up to 24 injectors, interface with a driveshaft speed sensor, and is compatible with drive-by-wire throttle bodies. It can also interface directly with a 4L60E or a 4L80E transmission.
Damon Sampson: With the tuning software that’s out there these days, factory GM computers have been proven to be very capable in performance applications. That said, Mast Motorsports’ stand-alone systems are easier to tune, and offer a wide range of parameters that are easily accessible. We offer two models of computers, the M90 and the M120. The primary difference between them is that the M90 uses dual narrowband O2 sensors, while the M120 has dual wideband sensors. Both computers are designed for a wide variety of applications, ranging from hot rods to airboats to marine applications. As such, our systems feature very durable, OE-like construction with sonic-welded connections and marine-grade wiring. This reduces the potential for wires getting brittle and connections going bad. You can even put our computers under water and they’ll still work. One of the unique features of Mast’s computers is the octane learn function. It continually monitors the knock sensors, and allows you to run on the ragged edge of pump gas. If you were to get a bad batch of gas, the computer will detect this, and dial back timing accordingly. Furthermore, both the M90 and M120 have nitrous and boost controls, and for drive-by-wire motors, you can even tune the sensitivity of the gas pedal.
Rick Anderson: Many hot rodders are intimidated by EFI, but Holley has taken measures with our EFI systems to make the installation process as easy as possible. Unlike trying to retrofit a factory GM wiring harness, there is no cutting or splicing involved with our HP and Dominator systems. Our harnesses plug right into the factory LS sensors. All you have to do is connect our harness to the motor, hook up the power and ground, and turn the key. We can’t stress enough the importance of taking your time to wire a vehicle properly. Most problems are attributable to people trying to take shortcuts or not following the directions. For those who need more assistance, we are currently setting up a network of Holley dealers across the country who can help with installation and tuning of Holley EFI systems. To find a dealer near you, check out the map on our website.