Perrin Front Mount Intercooler Boost Tube Kit Black 2015-2021 STI | 2.25” to 2.75” Diameter | Aluminum Boost Tubes
Overview
The Perrin Front Mount Intercooler Boost Tube Kit is a precision-engineered upgrade designed exclusively for the 2015-2021 Subaru WRX STI. This kit replaces the factory boost tubes with CNC mandrel bent aluminum piping that optimizes airflow from the turbocharger through the intercooler to the throttle body. It is tailored for STI owners seeking to reduce boost pressure drop, improve throttle response, and unlock additional power potential without the immediate need for ECU tuning.
Built with a focus on airflow efficiency and durability, the boost tubes feature a progressive diameter design, expanding from 2.25 inches at the turbo outlet to 2.75 inches near the intercooler and throttle body. The smooth mandrel bends minimize turbulence, while the black powder coat finish provides corrosion resistance and an OEM+ aesthetic. Included are custom CNC-machined aluminum brackets and upgraded coolant and washer fluid tanks to accommodate the new routing, reflecting Perrin’s commitment to functional, high-quality components.
This boost tube kit delivers proven gains of 10 to 20+ wheel horsepower across various power levels by improving charge air cooling and reducing pressure losses. The design maintains OEM clearance for straightforward installation and compatibility with other modifications. Subaru WRX STI owners will notice enhanced throttle response and more consistent boost delivery, making this an essential upgrade for both street and track use.
Features & Specifications
This Perrin Front Mount Intercooler Boost Tube Kit is engineered for the 2015-2021 Subaru WRX STI and features a progressive diameter design from 2.25” to 2.75”. Constructed from lightweight aluminum with a durable black powder coat finish, it delivers improved airflow and boost efficiency for Subaru enthusiasts seeking reliable power gains without mandatory tuning.
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Brand: Perrin Performance
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Product: Front Mount Intercooler Boost Tube Kit Black
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Part Number: PSP-ITR-438-3BK
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Fitment: 2015-2021 Subaru WRX STI
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Material: Aluminum
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Finish: Black powder coat
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Construction: CNC mandrel bent tubing
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Origin: USA (Perrin Performance)
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Tube Diameter: 2.25” (turbo outlet) to 2.75” (intercooler/throttle body)
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Included Tanks: Aluminum coolant overflow and washer fluid tanks
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Mounting: CNC-machined direct-mount aluminum brackets
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Power Gains: +10 to 20+ Wheel HP (dyno proven)
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Tuning Required: No (tuning recommended for additional gains)
Key Benefits
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Performance: Reduces boost pressure drop for improved throttle response and more consistent power delivery.
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Durability: Powder-coated aluminum resists corrosion and maintains a clean appearance over time.
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Fitment: Designed specifically for 2015-2021 STI with OEM clearance for hassle-free installation and compatibility with other mods.
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Quality: CNC mandrel bending ensures smooth airflow and structural integrity, minimizing turbulence.
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Value: Adds significant horsepower gains without requiring immediate ECU recalibration.
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Completeness: Includes upgraded coolant and washer tanks for proper boost tube routing and fitment.
What's Included
- 1× Perrin Front Mount Intercooler Boost Tube Kit Black
- 1× Perrin Aluminum Coolant Overflow Tank (powder coated)
- 1× Perrin High Capacity Aluminum Washer Fluid Tank
- Direct-mount CNC-machined aluminum intercooler brackets
- All necessary mounting hardware
- Installation instructions
Installation & Compatibility
Installation of the Perrin Boost Tube Kit is moderately straightforward for enthusiasts with basic mechanical skills and common hand tools. The kit is designed for direct bolt-on fitment with no permanent modifications required. The included coolant and washer tanks simplify routing and clearance issues commonly encountered with larger diameter piping. While no ECU tuning is required to safely run this kit, proper tuning is recommended to maximize power gains and ensure optimal engine performance. Always verify compatibility with your specific STI model year and any other aftermarket modifications installed.
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Professional Installation: Recommended for best results
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Modifications Required: None
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Verify Compatibility: Confirm fitment for 2015-2021 Subaru WRX STI
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