Boost Leash Instructions: A Comprehensive Guide
Boost Leash offers a unique 5-stage time-based boost control, plus a launch stage, ideal for both street and race applications. This guide details installation and tuning.
Boost Leash systems represent a significant advancement in boost control technology, offering precision and flexibility beyond traditional methods. Unlike conventional boost controllers, the Boost Leash utilizes a time-based approach, allowing for staged boost increases over a defined period. This is particularly beneficial for maximizing traction and minimizing wheelspin during launches, as evidenced by its popularity among drag racers.
The system’s core functionality revolves around a programmable controller that manages CO2 pressure to wastegates. This allows for incredibly rapid boost response and precise control, a feature highlighted by users desiring quick boost delivery on the street. Compatibility extends to various setups, including those utilizing stock ECUs with HPTuners, and even integration with Holley systems is possible.
Furthermore, the Boost Leash is often paired with components like the Motion Raceworks CO2 kit for streamlined installation, and mounting solutions like those from Fat House Fab ensure secure placement within the vehicle; Its ability to add boost incrementally, based on elapsed time, sets it apart.
What is a Boost Leash and its Function?
The Boost Leash is an electronic boost controller distinguished by its 5-stage, time-based control system, coupled with a dedicated launch stage. It doesn’t simply hold a set boost level; instead, it progressively increases boost over time, offering unparalleled control over turbocharger output. This functionality is achieved through precise CO2 regulation to the wastegate(s), enabling rapid adjustments.
Its primary function is to optimize boost delivery for various driving conditions. During a launch, the launch stage provides an immediate boost increase, enhancing off-the-line acceleration. Subsequently, the 5-stage time-based system ramps up boost, tailoring it to the demands of the race or street.
Users appreciate its ability to fine-tune boost curves, maximizing power while maintaining safe operating parameters. The simple 3-wire hookup – 12V, ground, and launch input – simplifies integration, and the system’s adaptability extends to both single and dual wastegate configurations.
Boost Leash vs. Traditional Boost Controllers
Traditional boost controllers typically focus on maintaining a single, set boost pressure. The Boost Leash diverges from this approach with its time-based, multi-stage control. Unlike controllers that react to manifold pressure, Boost Leash proactively adds boost based on elapsed time, offering a more aggressive and predictable response.
Many conventional systems struggle with rapid boost adjustments, particularly during launches. Boost Leash’s dedicated launch stage addresses this, delivering an immediate boost increase for superior acceleration; Furthermore, its 5-stage system allows for a boost curve tailored to the specific needs of the application, something often lacking in simpler designs.
Compatibility is also a key differentiator. Boost Leash functions effectively with stock ECUs and tuning platforms like HPTuners, while also integrating seamlessly with Holley systems, providing flexibility for diverse setups.

Installation Overview
Installation requires a CO2 tank, lines, and fittings, alongside the Boost Leash controller itself. Proper mounting and secure connections are crucial for safe operation.
Required Components for a Boost Leash Installation

A complete Boost Leash installation necessitates several key components beyond the controller unit itself. First, a CO2 tank is essential, sized appropriately for your boost requirements and anticipated usage duration. Consider a tank with sufficient capacity for multiple passes or extended street driving.

Next, you’ll need high-pressure CO2 lines, specifically designed for this application, ensuring they are compatible with the tank and controller fittings. A T-fitting is often utilized for wastegate connections, simplifying the plumbing. Don’t forget the necessary adapters to connect the CO2 lines to your wastegate(s).
Furthermore, a Motion Raceworks twin wastegate CO2 kit can be incredibly helpful, especially when running dual wastegates. Finally, ensure you have a bracket for secure controller mounting, like the Fat House Fab bracket, and appropriate wiring for power and launch input connections. Having all these components prepared beforehand streamlines the installation process.
Tools Needed for Installation
Successfully installing a Boost Leash requires a selection of tools to ensure a secure and reliable setup. Standard wrenches and sockets are crucial for tightening fittings and mounting components. A tubing cutter is essential for cleanly cutting CO2 lines to the correct length, preventing leaks and ensuring proper connections.
Additionally, a screwdriver set, encompassing both Phillips and flathead types, will be needed for various mounting and wiring tasks. Wire strippers and crimpers are vital for making secure electrical connections, particularly for the 12V power supply and launch input wiring.
A multimeter is highly recommended for verifying electrical continuity and voltage. Teflon tape is indispensable for sealing threaded connections, preventing CO2 leaks. Finally, safety glasses are paramount for protecting your eyes during the installation process, especially when working with pressurized CO2 systems.
Safety Precautions During Installation
Prioritizing safety is paramount when installing a Boost Leash system, particularly due to the involvement of high-pressure CO2. Always wear safety glasses to protect your eyes from potential leaks or debris. Ensure the work area is well-ventilated, as CO2 can displace oxygen. Never attempt to loosen or tighten CO2 tank fittings while the tank is pressurized.
Before commencing any electrical work, disconnect the vehicle’s negative battery terminal to prevent short circuits. Exercise caution when routing CO2 lines, avoiding sharp bends or contact with hot exhaust components. Double-check all connections for tightness before introducing CO2 into the system.
If you are unfamiliar with CO2 systems or automotive electrical work, seek assistance from a qualified professional. Always follow the manufacturer’s instructions and guidelines. Remember, improper installation can lead to system failure or, more seriously, personal injury.
CO2 System Integration
Integrating the CO2 system involves secure tank mounting, careful line routing, and utilizing a T-fitting for wastegate connection, ensuring optimal boost control performance.
CO2 Tank Mounting and Placement
Securely mounting the CO2 tank is paramount for safety and functionality. The trunk is a common location, providing ample space and protection. Ensure the tank is firmly fastened to prevent movement during vehicle operation, utilizing straps or a dedicated mounting bracket.
Consider accessibility for refills when choosing a location. Avoid areas prone to extreme temperatures, as this can affect CO2 pressure. Proper ventilation is also crucial, as CO2 is heavier than air and can displace oxygen in enclosed spaces.
Utilize a high-quality regulator specifically designed for CO2 and boost control applications. Regularly inspect the tank, regulator, and all connections for leaks or damage. A Motion Raceworks twin wastegate CO2 kit can aid in a professional and secure installation. Prioritize safety by following all manufacturer guidelines and local regulations regarding CO2 handling and storage.
CO2 Line Routing and Connections
Routing the CO2 lines requires careful planning to ensure efficient operation and prevent interference with other vehicle components. Use high-pressure CO2 hose specifically rated for this application, avoiding kinks or sharp bends that could restrict flow.
A T-fitting can simplify connections to the wastegate, particularly in setups without dual wastegates. Instead of running separate lines, combine the CO2 pressure line after the solenoids into a single feed for the wastegate. Ensure all connections are tight and leak-free, utilizing appropriate thread sealant.
Prioritize safety by keeping the lines away from hot exhaust components and moving parts. Secure the lines with clamps or brackets to prevent chafing or accidental disconnection. Double-check all fittings and connections before applying CO2 pressure, and regularly inspect for any signs of wear or damage. Proper line routing is vital for consistent boost control.
Using a T-Fitting for Wastegate Connection
Employing a T-fitting streamlines the CO2 line setup, especially beneficial when a dual wastegate system isn’t utilized. This method consolidates the CO2 pressure after the solenoids into a single line feeding the wastegate, reducing complexity and potential leak points.
Installation is straightforward: connect the CO2 line from the solenoids to the T-fitting’s main port. Then, attach a separate line from each outlet of the T-fitting to the wastegate actuator. Ensure all connections are secure, utilizing appropriate thread sealant to prevent leaks.
This approach is favored by some installers as it simplifies the plumbing. However, verify compatibility with your specific wastegate and Boost Leash configuration. Regularly inspect the T-fitting and connections for any signs of wear or leakage to maintain optimal boost control and system reliability.
Wiring and Electrical Connections
The Boost Leash requires a simple three-wire hookup: 12V power, ground, and a launch input signal. A video demonstration is available for visual guidance.
12V Power Supply Connection
Establishing a reliable 12V power supply is crucial for the Boost Leash controller’s operation. Ensure the power source is switched, meaning it turns on and off with the vehicle’s ignition. Avoid connecting directly to the battery, as this can lead to potential issues with the controller remaining active even when the car is off, draining the battery.

Locate a suitable fused 12V source within the vehicle’s interior. Many users successfully tap into existing accessory circuits. Use a properly sized fuse – typically 5A to 10A – to protect the controller and the vehicle’s electrical system. A clean and secure connection is paramount; solder and heat shrink are recommended over simple wire taps for long-term reliability. Double-check the polarity before connecting; reverse polarity can damage the unit.
Verify the voltage at the connection point with a multimeter to confirm a stable 12V supply. Poor grounding or a fluctuating voltage can cause erratic behavior or damage to the Boost Leash. Proper power connection ensures consistent and accurate boost control.
Ground Connection
A solid ground connection is as vital as the 12V power supply for the Boost Leash controller’s performance. Poor grounding is a common source of issues, leading to inaccurate readings, intermittent operation, and potential damage to the unit or other vehicle electronics. Avoid using the chassis as a primary ground point, as resistance can vary and create unreliable connections.
Instead, seek out a dedicated grounding location. A clean, unpainted metal surface directly bolted to the engine block or the vehicle’s frame is ideal. Use a heavy-gauge wire (12-14 AWG) to minimize resistance. Ensure the connection is secure – a star washer can help bite into the metal surface.
Inspect the ground connection for corrosion regularly. Clean any corrosion with a wire brush to maintain optimal conductivity. A multimeter can verify the ground connection’s integrity; resistance should be as close to zero ohms as possible. A robust ground ensures stable operation and accurate boost control.
Launch Input Wiring – Simple 3-Wire Hookup
The Boost Leash utilizes a straightforward 3-wire hookup for its launch input, simplifying integration with most automatic transmissions featuring a transbrake or similar launch control system. This input activates the launch stage boost profile, delivering maximum boost off the line for optimal acceleration.
The three wires required are 12V power, ground, and the launch input signal. Connect the 12V wire to a switched 12V source that is active during cranking and running. The ground wire, as previously detailed, needs a solid connection to the chassis or engine block. The launch input wire connects to the negative signal wire from your transbrake switch or launch control module.

When the transbrake is activated, this signal wire grounds, triggering the Boost Leash’s launch stage. A video demonstration is available at https://youtu.be/yEXmNoDtSGg for visual guidance. Proper wiring ensures seamless launch control integration.

Configuration and Tuning

Boost Leash allows precise boost adjustments via its 5-stage time-based control. Fine-tune boost levels for street driving or maximize performance on the race track, utilizing the launch stage;
Setting Up the 5-Stage Time-Based Boost Control

The Boost Leash’s core functionality revolves around its 5-stage time-based boost control. This system allows for incredibly precise manipulation of boost pressure throughout the acceleration process. Each stage is programmed with a specific boost level and a corresponding time delay. As time elapses from the initial launch or throttle application, the controller sequentially activates each stage, ramping up boost accordingly.
To begin setup, determine the desired boost profile for your application. Consider starting with lower boost levels in the initial stages to enhance traction and gradually increasing boost as speed builds. The controller’s interface allows for individual adjustment of both the boost target and the activation time for each of the five stages. Experimentation is key to finding the optimal settings for your vehicle and driving style.
Remember that the timing is relative to the initial trigger – typically the activation of the transbrake or throttle input. Careful calibration of these time delays is crucial for achieving smooth and predictable boost delivery. Utilize data logging to monitor boost response and refine your settings for peak performance.
Adjusting Boost Levels for Race and Street Use
Boost Leash excels in its adaptability for both demanding race conditions and comfortable street driving. For street use, prioritize a conservative boost profile. Lower boost levels throughout the stages ensure drivability and minimize stress on engine components. Focus on a smooth, progressive increase in boost, avoiding abrupt spikes that could compromise control.
Transitioning to race mode demands a more aggressive approach. Higher boost targets in each stage unlock maximum power potential for drag racing or other competitive applications. The 5-stage system allows for fine-tuning to match track conditions and your vehicle’s capabilities. Consider a steeper boost ramp-up for quicker acceleration, but be mindful of traction limitations.
The ability to quickly switch between pre-configured race and street profiles is a significant advantage. Save distinct settings within the controller to effortlessly adapt to different driving scenarios. Remember to monitor boost levels closely and adjust as needed to optimize performance and maintain engine safety.
Utilizing the Launch Stage Feature
Boost Leash’s launch stage is a game-changer for maximizing traction and minimizing wheelspin during drag racing starts. This feature delivers an immediate and substantial boost increase precisely when you release the transbrake or launch control device. The rapid boost delivery helps plant the tires and propel you forward with authority.

Proper configuration is crucial. Experiment with different launch stage boost levels to find the optimal setting for your vehicle and track conditions. Start conservatively and gradually increase boost until you achieve the desired launch characteristics. Monitor 60-foot times to gauge effectiveness.
The timing of the launch stage is also critical. Adjust the duration to ensure the boost spike coincides perfectly with your launch. A well-tuned launch stage can significantly improve your reaction time and overall drag strip performance. It’s a key element for consistent, hard launches.
Advanced Features and Considerations
Boost Leash seamlessly integrates with dual wastegate systems, stock ECUs, and tuning platforms like HPTuners and Holley, offering versatile control options for performance.
Integrating with Dual Wastegate Systems
Boost Leash excels when paired with dual wastegate setups, providing precise boost control for symmetrical turbocharger performance. Utilizing a Motion Raceworks twin wastegate CO2 kit simplifies the installation process, ensuring balanced pressure regulation. Instead of running separate lines to each wastegate, a T-fitting can be employed in the combined CO2 pressure line after the solenoids, streamlining the setup.
This approach maintains consistent boost delivery to both wastegates, maximizing efficiency and responsiveness. With four springs installed, users have reported achieving boost levels of 24.5 PSI, demonstrating the system’s capability. Proper spring selection is crucial for optimal performance within your desired boost range; The Boost Leash’s ability to add boost quickly, based on time after transbrake release, is particularly beneficial for dual wastegate configurations, enhancing hookup on various surfaces;
Careful consideration of CO2 line routing and secure connections is paramount for safe and reliable operation.
Compatibility with Stock ECUs and HPTuners
Boost Leash demonstrates excellent compatibility with factory ECUs and tuning software like HPTuners, offering a standalone boost control solution without requiring a complete engine management overhaul. This is particularly appealing for users who prefer to retain their existing tuning setup and avoid the complexities of transitioning to a different system, such as Holley.
Users running stock ECUs alongside HPTuners have successfully integrated the Boost Leash, leveraging its 5-stage time-based control and launch stage features to optimize boost delivery. The system operates independently of the ECU’s boost control mechanisms, providing an additional layer of precision and adjustability.
This allows for fine-tuning boost levels for various driving conditions, from street cruising to aggressive track performance, without altering the core engine calibration. The simple 3-wire hookup – 12V, ground, and launch input – further simplifies integration.
Using with Holley Systems
While Boost Leash is readily compatible with stock ECUs and HPTuners, its integration with Holley performance management systems requires careful consideration. Although some users may prefer the standalone functionality of Boost Leash, Holley systems often possess robust, integrated boost control capabilities.
However, the Boost Leash can still be utilized with Holley systems as a supplementary control method, particularly for advanced applications demanding precise boost manipulation. This might involve leveraging the Boost Leash’s 5-stage time-based control alongside Holley’s existing features for a layered approach to boost management.
It’s important to note that direct integration may necessitate custom wiring and configuration to ensure seamless communication and avoid conflicts between the two systems. Users should consult with experienced tuners familiar with both Boost Leash and Holley to optimize performance and reliability.
















































































