CO2 Boost Control Dual Solenoid & Pressure Sensor Kit Thread: 1/8 NPT

Precision Pneumatic Management: CO2 Boost Control Dual Solenoid Kit

In high-horsepower drag racing and land-speed applications, traditional manifold-referenced boost control often lacks the authority to hold massive wastegate springs shut. The CO2 Boost Control Dual Solenoid & Pressure Sensor Kit is the professional solution for extreme boost management. By using a pressurized CO2 or compressed air source rather than manifold pressure, this kit allows for closed-loop boost control that is independent of engine vacuum or boost. This system provides the ECU with the power to force a wastegate shut or open with surgical precision, regardless of exhaust backpressure. For builders of 2JZ, RB26, or Twin-Turbo LS drag cars, this kit is the industry standard for achieving 60+ PSI of stable, repeatable boost.

The Engineering of CO2 Control Logic

The kit utilizes two 3-port 33Hz boost control solenoids. This “dual solenoid” configuration allows for the ECU to independently control the pressure being applied to the top of the wastegate diaphragm and the pressure being vented. This is far superior to a single 3-port or 4-port solenoid because it allows for a “Hold” state where pressure is trapped in the wastegate line, minimizing CO2 consumption. The kit also includes a 150 PSI “TI” wastegate pressure sensor. This sensor provides the Analogue-to-Digital interface necessary for the ECU to monitor exactly how much pressure is acting on the wastegate. By comparing this to the target map, the ECU can adjust the solenoid duty cycles in real-time, resulting in a boost curve that is a perfectly straight line on the data log.

Operational Benefits for Drag Racing

The primary benefit of CO2 control is the ability to run a light wastegate spring (for easy staging and low boost in 1st gear) while still being able to reach massive boost levels in the later stages of the run. Because the CO2 source is typically regulated to 60-100 PSI, the ECU has more than enough authority to overcome the exhaust pressure trying to force the gate open. This is essential for detonation protection; by having absolute control over boost, the tuner can ensure the engine never sees an unexpected spike. Furthermore, the 33Hz solenoids provide a high-resolution signal, ensuring that the fuel map calibration remains stable because the air-load is consistent and predictable.

Fitment, Plumbing, and Harness Integration

This kit uses standard 1/8 NPT threads for all connections, making it compatible with a wide range of AN fittings and push-lock hoses. The inclusion of a -4 AN adaptor and “T” fitting simplifies the installation of the 150 PSI sensor into the wastegate line. During harness integration, the two solenoids should be wired to high-current DPO outputs on the Haltech Elite or Nexus. It is recommended to mount the solenoids as close to the wastegate as possible to minimize pneumatic lag. The kit is universal and can be adapted to any engine platform utilizing external wastegates (Tial, Turbosmart, etc.).

Technical Specifications

Summary & Includes

The CO2 Boost Control Kit is the definitive tool for high-pressure boost management. Includes: 2 x 3-Port Solenoids, 150 PSI Pressure Sensor, -4 AN Adaptor, and “T” Fitting. Note: CO2 bottle and regulator are sold separately.