Solenoid - Boost Control

The Holley Solenoid - Boost Control (part number 557-201) is a dual-port boost control solenoid engineered for precise turbocharger or supercharger boost regulation in EFI-equipped engines. This component sits at the heart of boost management systems, modulating wastegate or bypass valve operation to maintain target boost pressure across the entire RPM range. Designed for serious performance builders and tuners, the Holley boost control solenoid delivers the precision regulation required for consistent power delivery and engine protection.

Built with Holley's expertise in EFI system integration, this dual-port solenoid accommodates both vent and boost signal lines, allowing fine-tuned control strategies across varying load conditions. The included fittings simplify installation and ensure compatibility with standard boost control plumbing. Weighing just 1.05 lbs with compact dimensions of 3.4 x 3.4 x 5.7 inches, the unit fits easily within engine bay constraints typical of both street and race applications. The solenoid's response characteristics enable smooth boost transitions and prevent boost creep, which is critical for maintaining reliability in turbocharged or supercharged powerplants operating at elevated boost levels.

This component is essential for builders implementing Holley EFI systems on turbocharged or supercharged engines where factory boost control solutions are unavailable or insufficient. It serves street performance, bracket racing, and road course competitors who require adaptive boost management for varying weather, elevation, and fuel quality conditions. Engine builders integrating forced induction into vintage platforms or modern swaps rely on this solenoid to bridge the gap between engine demand and compressor output, ensuring both performance and longevity.

Boost control solenoids are fundamental to any well-tuned forced-induction system. Unlike carbureted or basic fuel-injected engines, EFI platforms allow dynamic boost regulation that responds to operating conditions in real time. The Holley boost control solenoid integrates seamlessly with Holley's tuning software, enabling users to define boost curves and response parameters that optimize both acceleration and top-end stability. Proper boost control prevents detonation, reduces turbo lag effect, and protects internal engine components from overboosting scenarios.