StealthBox Cold Air Intake

The GrimmSpeed StealthBox Cold Air Intake in black for the 2015-2018 Subaru WRX is engineered to provide enhanced airflow and performance while mitigating heat soak. This enclosed system seals the air filter from ambient engine bay temperatures, drawing cooler air directly from the factory intake duct. Constructed from 6061 aluminum with a durable wrinkle black powdercoat finish, it's designed for optimal performance and longevity. The StealthBox design directly addresses heat soak issues prevalent in open-element intakes on the FA20DIT platform. By sealing the filter within an enclosure and utilizing the factory cold air inlet, it consistently achieves lower intake air temperatures. Installation is straightforward, as it integrates with the existing intake architecture, retaining the factory MAF sensor position and cold air duct without requiring modifications to the factory routing or MAF relocation. Performance gains are significant, with dyno testing showing an additional 32 ft-lb of torque at 3000rpm and 21 wheel horsepower at 5500rpm. The system is designed in CAD with a low bend angle aluminum tube to minimize restriction. It is manufactured in the USA. Crucially, tuning is required after installation of the GrimmSpeed StealthBox Cold Air Intake for the 2015-2021 WRX to maximize performance and ensure engine safety. It is not compatible with the factory tune or any off-the-shelf maps. The package includes the CNC bent intake tube with MAF flange, high-flow dry air filter, aluminum heat shield, MAF harness extension, silicon hump coupler, clamps, gasket material, and MAF sensor screws.