Perrin Front Mount Intercooler Boost Tube Kit Red 2015-2021 STI | 2.25"-2.75" Diameter | Performance Boost Tubes
Overview
The Perrin Front Mount Intercooler Boost Tube Kit is a precision-engineered upgrade designed specifically for the 2015-2021 Subaru WRX STI. This kit replaces the restrictive OEM boost tubes with larger diameter, mandrel-bent aluminum tubes that optimize airflow from the turbocharger to the intercooler and throttle body. It is ideal for STI owners seeking to improve boost efficiency and power delivery without compromising reliability or requiring immediate ECU tuning.
Built with a stepped diameter design—starting at 2.25 inches at the turbo outlet and expanding to 2.75 inches near the intercooler and throttle body—these tubes reduce pressure drop and turbulence for smoother airflow. The CNC mandrel bending process ensures consistent internal diameter and smooth transitions, while oversized beaded ends secure silicone couplers firmly under all boost conditions. The kit also includes custom CNC-machined aluminum intercooler brackets, a powder-coated coolant overflow tank, and a high-capacity aluminum washer fluid tank to maintain proper clearance and OEM-level fitment.
By improving charge air cooling and reducing intake restriction, this kit has been dyno-proven to add 10 to 20+ wheel horsepower across various power levels. This balance of performance gains, durability, and ease of installation makes it a practical and effective upgrade for Subaru WRX STI enthusiasts who want reliable power improvements with the option to unlock further gains through tuning.
Features & Specifications
This Perrin Front Mount Intercooler Boost Tube Kit is engineered for the 2015-2021 Subaru WRX STI and features stepped boost tube diameters from 2.25" to 2.75". Constructed from lightweight CNC mandrel-bent aluminum, it delivers improved airflow and boost efficiency for Subaru enthusiasts seeking reliable power gains and OEM-level fitment.
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Brand: Perrin Performance
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Product: Front Mount Intercooler Boost Tube Kit Red
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Part Number: PSP-ITR-438-3RD
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Fitment: 2015-2021 Subaru WRX STI
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Material: CNC Mandrel-Bent Aluminum
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Finish: Powder Coated Red
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Construction: CNC Machined, Mandrel Bent Tubing
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Origin: Made in USA
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Boost Tube Diameter: 2.25" (Turbo Outlet) to 2.75" (Intercooler/Throttle Body)
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Included Tanks: Powder Coated Coolant Overflow Tank, 6061 Aluminum High Capacity Washer Fluid Tank
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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 required for stock ECU, tuning recommended for additional gains
Key Benefits
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Performance: Increased airflow reduces pressure drop, improving turbo efficiency and power delivery.
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Durability: CNC mandrel-bent aluminum tubes resist cracking and deformation under boost pressure.
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Fitment: Direct bolt-on installation with custom brackets and tanks maintains OEM clearance and engine bay packaging.
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Cooling Efficiency: Improved charge air cooling supports consistent performance during spirited driving or track use.
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Appearance: Powder-coated red finish adds a clean, performance-oriented look under the hood.
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Value: No immediate ECU tuning required, allowing power gains without additional expense or complexity.
What's Included
- 1× Perrin Front Mount Intercooler Boost Tube Kit Red
- 1× Powder Coated Coolant Overflow Tank
- 1× 6061 Aluminum High Capacity Washer Fluid Tank
- 1× Set of CNC Machined Direct-Mount Aluminum Intercooler Brackets
- Mounting hardware and silicone couplers
- Installation instructions
Installation & Compatibility
The Perrin Front Mount Intercooler Boost Tube Kit installs using OEM-style mounting points with included hardware, making it largely bolt-on. Basic hand tools and mechanical experience are recommended to ensure proper fitment and hose routing. The included coolant overflow and washer fluid tanks provide necessary clearance for the larger boost tubes without requiring modifications to the engine bay. No ECU tuning is required for stock vehicles, but owners planning further modifications should consider professional tuning to maximize power gains and maintain safe operation.
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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 models
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