FAST XFI 2.0 EFI: Power & Precision

Unlocking Engine Potential: The FAST XFI 2.0 EFI System

For enthusiasts seeking to elevate their vehicle's performance, particularly those with classic American V8s, the transition from carburetion to electronic fuel injection (EFI) represents a significant leap forward. Among the leading solutions in this domain, the FAST XFI 2.0 EFI kit stands out as a comprehensive and powerful upgrade. Designed to be a bolt-on, fully sequential EFI system, it caters to a wide spectrum of applications, from mild street rods to high-horsepower race cars, specifically for Small and Big Block Chevy and Small Block Ford engines. This article delves into the intricacies of the FAST XFI 2.0, exploring its hardware, software advancements, unique technologies, and how it empowers tuners and drivers alike.

What is the FAST XFI 2.0 EFI Kit?

The FAST XFI 2.0 EFI kit is a sophisticated engine management system engineered to replace traditional carburettors with modern, precise electronic fuel injection. It offers a fully sequential injection system, meaning that each fuel injector fires at the precise moment required for optimal combustion within its respective cylinder. This level of control translates into a host of benefits, including improved fuel economy, enhanced throttle response, easier cold starts, and a broader power band. The kit is designed as a complete package, typically including the XFI ECU, a Dual-Sync Distributor for accurate timing, a single-plane aluminium intake manifold, a 4-barrel throttle body, correctly sized Precision-Flow Fuel Injectors, aluminium fuel rails, a fuel pump kit, all necessary sensors, and professional-grade wiring harnesses with clearly labelled connectors. A comprehensive installation and tuning DVD is also usually included, guiding users through the process.

Hardware: Power and Durability

At the heart of the XFI 2.0 system lies its advanced ECU (Engine Control Unit). This unit leverages the latest in flash microprocessor technology, resulting in a significant increase in processing speed. The XFI 2.0 can process, analyse, and adjust engine parameters up to four times faster than its predecessors. This enhanced processing power is crucial for managing complex engine demands, especially in high-performance or boosted applications. The ECU's durability is further bolstered by a surface-mount component circuit board and a robust billet ECU enclosure, ensuring reliable operation even under the demanding conditions of racing or aggressive street driving. To further simplify the installation process, FAST offers engine-specific XFI 2.0 Wiring Harnesses. These harnesses are meticulously designed with clearly labelled connections, reducing the complexity and potential for errors during installation, a common pain point for DIY enthusiasts.

Software Advances: User-Friendly Control

The control and tuning of the XFI 2.0 are managed through the C-Com XFI Windows-based software. This software is renowned for its intuitive navigation and user-friendly interface, making it accessible even to those new to EFI tuning. A standout feature is its field-flashable capability, which allows users to download the latest software updates via email or directly from the FAST website. This means tuners can stay current with the most advanced algorithms and features without ever needing to physically remove the XFI 2.0 ECU from their vehicle, a testament to the system's modern design philosophy.

Key Technologies: Qwik Tune and Diagnostics

One of the most innovative features of the XFI 2.0 is its Qwik Tune Technology. This groundbreaking feature enables ECU programming without the need for a laptop. Users can pre-programme up to four distinct EFI maps (or tunes) and then select the desired tune-up with the simple flick of an in-car switch. This versatility allows for instant optimisation of engine performance for various driving conditions – one tune for everyday cruising, another for aggressive racing, and perhaps a third for maximum fuel economy. Beyond tuning flexibility, the XFI 2.0 incorporates valuable diagnostic features. On-board diagnostics and EZ Test Indicator Lights provide clear visual feedback on system status, aiding in troubleshooting. The system also includes a five-bar MAP (Manifold Absolute Pressure) sensor, which is essential for accurate load calculation, and offers dedicated controls for power adders (like superchargers or turbochargers) and torque converter lockup, further expanding its tuning capabilities. Enhanced data logging capabilities and memory for analysing up to 8 additional monitored inputs provide tuners with the tools to meticulously refine engine performance.

FAST XFI Sportsman: Bridging the Gap

While the XFI 2.0 is a powerhouse for serious racers, FAST recognised a need for a system that catered to the enthusiast who enjoys both spirited driving and occasional track days, but perhaps doesn't require the absolute pinnacle of racing-specific features. This is where the XFI Sportsman EFI system comes into play. Positioned between the entry-level EZ-EFI and the high-end XFI 2.0, the XFI Sportsman offers a compelling blend of ease of use and advanced control, making it an ideal choice for boosted applications and street/strip vehicles. As demonstrated in the 'Biting The Bullitt' project, the XFI Sportsman proved to be a transformative upgrade, moving from a blow-through carburettor system to a precise EFI setup. This transition yielded significant improvements in power delivery and drivability, enabling the car to achieve impressive nine-second elapsed times.

XFI Sportsman Features and Capabilities

The XFI Sportsman system is designed to be highly capable, incorporating many of the desirable features found in both the EZ-EFI and XFI 2.0 systems. It provides a fully programmable, bank-to-bank EFI setup suitable for a wide range of engine configurations. While it requires an external laptop for initial setup and tuning using the C-Com software, much like the XFI 2.0, its installation is streamlined. The system typically ships with the ECU, wiring harnesses, a wideband oxygen sensor, and an electronic fuel pressure kit. Key differentiators from the XFI 2.0 include the absence of certain advanced control features like progressive nitrous control, transbrake control, or traction control. However, in terms of spark and fuel management, the XFI Sportsman offers full tunability, mirroring the XFI 2.0's capabilities. It includes tables for monitoring and adjusting fuel, timing, and air/fuel targets, a user-configurable auxiliary input channel, and a full-function datalogger. Crucially, it fully supports boosted applications up to 5 bar of boost and includes timing retard functions for wet nitrous systems.

Tuning Strategies: Speed Density vs. Alpha-N

A critical aspect of EFI tuning is the fuel strategy employed. The XFI Sportsman system supports both Speed Density and Alpha-N fueling strategies. Speed Density, often favoured for its consistency, calculates fuel requirements based on air temperature and air pressure (measured by the MAP sensor), along with engine displacement and desired air/fuel ratio. This method ensures that fuel delivery remains accurate as atmospheric conditions change. Alpha-N, on the other hand, relies on throttle position and RPM, making it suitable for applications with unstable manifold vacuum, such as individual runner induction systems. The ECU calculates air density using atmospheric pressure and temperature, then uses engine displacement and the target air/fuel ratio to determine the precise amount of fuel to inject. The Volumetric Efficiency (VE) of the engine is a key variable in this calculation, representing how well the cylinders are filled. By calibrating the VE table, tuners can ensure the engine runs at the desired air/fuel ratio across different load and speed points. Once properly calibrated, the VE table provides an accurate airflow prediction, allowing the ECU to automatically adjust fuel delivery for varying atmospheric conditions without manual intervention.

Fuel Delivery: Injectors and Fuel Rails

Effective fuel delivery is paramount for any EFI system. For the 'Biting The Bullitt' project, DeatschWerks DV2 1200cc fuel injectors were chosen. These high-impedance injectors, utilising EV14 technology, are among the largest available and offer several advantages. They provide a simple plug-in connection with the XFI Sportsman's included adapter connectors. Flow-matched using DeatschWerks' multi-point dynamic flow testing, they ensure consistent fuel delivery. Importantly, these injectors are compatible with a wide range of fuels, including race fuels, MTBE oxygenated fuels, ethanol blends (like E85), and methanol blends. The injectors are supplied with comprehensive characterization data, which is vital for accurate tuning, leading to better idle quality, drivability, and power output. It's important to note that injector performance can vary with fuel pressure, so verifying injector data based on the intended fuel pressure is crucial during the tuning process.

The Role of the FAST eDash

Complementing the XFI Sportsman (and XFI 2.0) system is the FAST XFI eDash. This full-colour, touchscreen unit offers a compact digital dashboard that can display up to 20 live data readings simultaneously. Connected via a single plug-and-play harness, it provides real-time insights into crucial engine parameters such as Idle Air Control, Total Timing, Miles Per Gallon, O2 Correction %, Coolant Temperature, and Fuel Pump Duty Cycle. The eDash also allows for on-the-fly adjustments to Adaptive Learning settings, Torque Converter lockup MPH, and Rev Limiter for the XFI Sportsman. For XFI 2.0 users, it provides the ability to load different tunes and control power-adder settings. Its mounting points are compatible with Garmin GPS units, allowing for a clean and integrated installation.

Installation and Components

The installation of the FAST EFI systems, including the XFI Sportsman, is designed to be as straightforward as possible. The pre-terminated wiring harness significantly simplifies the process, eliminating the need for extensive custom wiring. Sensors are strategically located for easy access and connection. This plug-and-play approach allows users to lay out the harness, connect it to the required sensors, and be ready to go. The similarity in the harness design between the EZ-EFI and XFI Sportsman systems also allows for a seamless upgrade path without a complete rewiring of the vehicle. Other essential components for a complete EFI conversion often include intake manifolds from manufacturers like Edelbrock, designed specifically for EFI applications, and matching fuel rails. High-quality fuel lines and fittings from brands like Russell Performance are also critical for ensuring reliable fuel delivery, with options like ProClassic II hose offering improved bend radius and durability.

Performance Gains and Drivability

The impact of installing a FAST XFI system, as seen in the 'Biting The Bullitt' project, can be transformative. The vehicle achieved a dyno-proven 824.5 horsepower after the XFI Sportsman installation, coupled with a significant improvement in drivability. The engine fired up instantly and settled into a smooth, refined idle, a stark contrast to the often-temperamental nature of carburetted setups, especially in high-performance applications. The ability to precisely control fuel and timing allows for a much broader power band and improved responsiveness across the rev range. The self-learning capabilities, combined with the extensive tuning options, empower users to achieve optimal performance tailored to their specific engine and driving needs.

Frequently Asked Questions

Q1: Does the XFI Sportsman know how much fuel to inject?
Yes, the XFI Sportsman calculates the amount of fuel to inject based on various sensor inputs (like MAP, air temperature, throttle position, and O2 sensor) and programmed parameters, including engine displacement and volumetric efficiency. Its self-tuning capability uses the wideband oxygen sensor to make real-time adjustments to achieve the target air/fuel ratio.

Q2: Can the XFI 2.0 control my power adder?
Yes, the XFI 2.0 system offers dedicated controls for power adders, allowing for precise management of boost or nitrous oxide systems, including progressive control for nitrous.

Q3: Is the XFI Sportsman suitable for highly modified engines?
Absolutely. The XFI Sportsman is designed for a wide range of applications, including boosted engines making up to 5 bar of boost, and offers full tunability for fuel and spark, making it suitable for significantly modified combinations.

Q4: Do I need a laptop to tune the XFI 2.0 or XFI Sportsman?
While the XFI 2.0 can be programmed without a laptop using its Qwik Tune Technology for pre-set maps, a laptop with the C-Com software is required for initial setup and advanced tuning for both the XFI 2.0 and XFI Sportsman systems. The eDash can provide on-the-fly adjustments for certain parameters.

Q5: How does the XFI 2.0 differ from the XFI Sportsman?
The XFI 2.0 is a more advanced system with additional features geared towards hardcore racing, such as progressive nitrous control and traction control. The XFI Sportsman offers a balance of performance and ease of use, catering to street/strip enthusiasts and those with boosted applications who may not need the extreme features of the XFI 2.0.

Conclusion

The FAST XFI 2.0 EFI system, along with its sibling the XFI Sportsman, represents a significant advancement in engine management technology for classic American V8s. By offering precise control over fuel and ignition, these systems unlock greater performance, improve drivability, and enhance fuel efficiency. Whether you're building a mild street rod or a dedicated race machine, FAST's EFI solutions provide the power, precision, and user-friendly features necessary to take your vehicle's performance to the next level.

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