COBB Tuning SF Air Intake Box - 2015-2018 Subaru STI

The Cobb SF Intake System: Built for the OTS Map

The Cobb SF Intake System for the 2015-2021 Subaru WRX STI is the intake that every Cobb Stage 2 OTS map is calibrated for. It's not just an intake — it's the intake that makes the Cobb tune deliver what Cobb publishes. The SF design uses a sealed airbox to draw from outside the engine bay heat, reducing intake air temperatures versus an open-element design that draws from hot underhood air.

Heat Is the Enemy of Power — The SF Airbox Knows This

Open-element intakes flow well in a controlled environment, but inside the engine bay of a turbocharged VA STI, they draw in heat-soaked air that the turbocharger and intercooler then have to deal with downstream. The Cobb SF airbox draws from a dedicated cold-air source, keeping intake temperatures closer to ambient. Cooler air is denser air — more oxygen per cubic foot means more fuel can be burned and more power made.

Bolt-On Installation, Matched to the Cobb Tune

The Cobb SF SF Intake System installs at the factory airbox location on the VA STI — the factory airbox comes out, the Cobb system goes in its place. The included high-flow filter and intake tube are sized and tuned for the Cobb Stage 2 OTS maps, meaning you get the power the map promises rather than a compromise from mismatched components.

Key Features

• Platform: 2015-2021 Subaru WRX STI
• SF sealed airbox design — draws from cold-air source, not hot engine bay air
• Calibrated to work with Cobb Accessport OTS maps
• Bolt-in installation at factory airbox location

Fitment Notes

• Platform: 2015-2021 Subaru WRX STI
• Direct bolt-in replacement — no modification required
• Confirm color/variant from product title or dropdown before ordering

Straight From Subispeed

The Cobb SF Intake is the intake to run if you are on a Cobb tune or planning to be — Cobb calibrated the Stage 2 OTS maps to this specific intake, and running it means you get the numbers they publish rather than an approximation. The sealed airbox design is particularly important for daily-driven cars where intake temperatures vary throughout the day — cold air source intake means consistent temps regardless of how hot the engine bay gets. If you are building a VA STI on the Cobb platform, this is the intake piece that belongs in the build.

What's Included

• Cobb SF SF Intake System
• High-flow intake filter
• Mounting hardware

About Cobb Tuning

Cobb Tuning has been developing performance parts and tuning solutions for Subaru vehicles since 1999. Based in Austin, Texas, Cobb built their reputation on the Accessport — the most widely used Subaru ECU tuning device on the market — and expanded that into a full ecosystem of intake, exhaust, drivetrain, and engine bay accessories engineered specifically for the platforms they support. Every Cobb product is developed in-house and validated on their own test vehicles before it reaches customers. Subispeed carries the full Cobb catalog because their engineering standards and platform-specific development process consistently produce parts that work exactly as advertised.