Air and Fuel› Air Cleaners, Filters, Intakes and Components

Grimmspeed

StealthBox Cold Air Intake

$425.00

SKU: 8985328025906

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Overview

The Grimmspeed StealthBox Cold Air Intake is designed for the 2015-2021 Subaru WRX. It aims to provide both performance and a stealthy aesthetic. The intake features a low-bend-angle aluminum tube and a shielded MAF sensor placement to ensure accurate readings and minimize restriction. It is made in the USA and constructed from 6061 aluminum with a 1/8 inch tube wall thickness.
Show original supplier description
The GrimmSpeed StealthBox Cold Air Intake system was developed to enhance the performance and acoustics of the 2015-2021 Subaru WRX. Inspired by the F-117 Nighthawk, its heat shield offers a stealthy look while effectively shielding the MAF sensor from engine bay heat, ensuring more accurate readings and increasing overall performance. The intake tube is constructed from 6061 aluminum with a 1/8 inch wall thickness and features a low-bend-angle design to minimize restrictions. Key specifications include a +32wtq (14.3%) and +21whp (9.6%) increase at specific RPMs, as verified by dyno testing. The design optimizes MAF sensor placement, bend angle (74 degrees total), and filter location within the fender, utilizing the factory ram-air scoop for a continuous supply of cool air. This enclosed cold air intake system combines the benefits of a traditional cold air intake with the protection of an airbox. Included components consist of a CNC-bent intake tube with MAF flange, a GrimmSpeed high-flow dry air filter, an aluminum heat shield, a 12" MAF harness extension, a silicon hump coupler, worm gear clamps, rubber gasket material, and MAF sensor screws. Installation requires tuning as it is not compatible with the factory tune or off-the-shelf maps. Proper tuning is essential after installation to maximize gains and ensure engine safety.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandGrimmspeed
Part Number8985328025906
CategoryAir and Fuel
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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