Protection Module - Transbrake Input

The Holley Protection Module – Transbrake Input (model 554-128) is a dedicated electronic control module engineered for transbrake systems in EFI-equipped vehicles. This compact unit manages the transbrake input signal pathway, providing the interface between launch control logic and transbrake solenoid activation. Designed for drag racing and high-performance competition environments, it conditions and protects the transbrake command signal from the main EFI controller, ensuring clean engagement and disengagement during staged launches.

The module's compact form factor (4.3 × 2.3 × 4.75 inches) allows flexible underhood mounting in tight engine bays. At just 0.27 lbs, it adds negligible weight while providing critical signal isolation and voltage regulation. The transbrake input protection circuit filters electrical noise and transient spikes inherent in high-current solenoid switching, protecting sensitive EFI processor pins from damage. This is particularly critical in competition vehicles where ignition timing advances, fuel injection pulses, and solenoid commands operate in close electrical proximity. Holley's proven architecture ensures signal fidelity across a full range of engine RPM and load conditions.

Built for bracket racers, Pro Stock teams, and dedicated drag racing programs running Holley EFI systems, this module is essential for reliable transbrake operation on the launch line. Whether competing in NHRA events or bracket racing at local tracks, consistent transbrake engagement directly impacts reaction time and overall elapsed time repeatability. The 554-128 integrates seamlessly into existing Holley EFI harnesses and works across the full Holley EFI product lineup, including traditional port injection and direct injection platforms used in competition motorsports.