Go Fast Bits Wastegate Actuator (Tune Required) Subaru STI 2004-2021 | 7305

Product Fitment:

2004-2021 Subaru STI

Enhance your Subaru WRX STI’s boost control, spool response, and tuning precision with the GFB WGA Wastegate Actuator. Engineered with a larger diaphragm, adjustable base pressure, and improved stroke length, this actuator offers superior boost stability and response under demanding conditions.

Key Features

• Larger Diaphragm Design – Offers more precise boost control and greater resistance to boost creep.

• Increased Stroke Length – Enables smoother actuation and improved high-RPM boost retention.

• Adjustable Base Boost Pressure – Comes with multiple springs (5, 7, and 10 psi) and supports base boost levels from ~5 psi to 24 psi with preload adjustments.

• Compact & Durable – Shorter body height allows better fitment in tight engine bays with high heat resistance.

• Tuning Friendly – Provides a reliable platform for custom boost control strategies.

Performance Benefits

• Faster spool-up and reduced turbo lag

• Tighter and more consistent boost curve across the RPM range

• Less boost taper at high engine speeds

• Better response to ECU boost control tuning

• Prevents premature wastegate opening under load

Installation & Tuning Notes

• Tune Required – Installing a higher-pressure actuator changes the boost profile. A retune is highly recommended to ensure safe and optimal performance.

• Spring Selection – Choose the appropriate spring combination based on your turbo setup and target base pressure.

• Proper Preload is Critical – Set preload correctly to avoid overboost or underboost conditions.

• Inspect System – Ensure the wastegate, actuator arm, and vacuum/boost reference lines are functioning properly before installation.

What’s Included

• 1 × GFB WGA Wastegate Actuator (Part #7305)

• 3 × Boost Springs (Approx. 5 psi, 7 psi, 10 psi)

• Turnbuckle Rod for Adjustable Preload

• Spring Chart & Installation Guide

The GFB WGA Wastegate Actuator is an essential upgrade for WRX STI owners looking for improved boost response, consistent turbo performance, and more precise tuning control. Whether you're chasing more power or refining your existing setup, this actuator offers a durable, reliable, and adjustable solution that outperforms stock wastegate units.