Lamborghini Huracan EVO STO Steering Rack 4S1423050L

the part number 4S1423050L identifies the Steering Rack (Steering Gear) for the Lamborghini Huracán STO (and certain EVO configurations). This is a highly specialized Electronic Power Steering (EPS) unit specifically tuned for the STO’s more direct, track-focused steering ratio.

1. Technical Identification

• Part Number: 4S1423050L

• Type: Electromechanical Power Steering (EPS). Unlike older hydraulic systems, this unit uses an integrated electric motor to provide assistance, allowing for variable steering weight based on the ANIMA drive mode (STREET, PIOGGIA, TROFEO).

• Steering Ratio: The “L” revision is specifically calibrated for the STO’s fixed-ratio steering. Unlike the standard Huracán, which often featured “Lamborghini Dynamic Steering” (LDS) with a variable ratio, the STO uses a fixed, more communicative ratio for consistent feedback on the track.

• Compatibility: While the physical housing may fit other Huracán models, the internal software and torque sensor calibration are unique to the STO’s suspension geometry and rear-wheel steering (RWS) integration.

3. Key Installation Notes

• Software Parameterization: This is not a simple “plug-and-play” part. Once the hardware is bolted in, the integrated control module must be parameterized and “flashed” with the correct steering map using the Lamborghini LaRA or ODIS diagnostic system. Without this, the power assistance will not activate, and the car will show a “Steering Defective” error.

• Rear-Wheel Steering (RWS) Sync: The STO features Rear-Wheel Steering. The front rack (4S1423050L) must communicate perfectly with the rear actuators. After installation, a “Neutral Position Calibration” must be performed for both the front and rear systems simultaneously.

   

• Hardware: The steering rack is secured to the front frame (subframe) with high-tensile bolts. It is standard practice to replace these bolts (N 911 158 01 or similar) during installation as they are often one-time-use stretch bolts.