AEM 2015+ Subaru WRX STi 2.5L H4 - Cold Air Intake System - Wrinkle Red

Brand: AEM

Product Code: 21-735WR

Availability:In stock

  • Increased horsepower
  • Tuned and dyno-tested to improve acceleration and engine sound
  • Low restriction aluminum tubing
  • Easy to install using commonly available tools
  • Air filter lasts up to 100,000 miles before cleaning is required (depending on driving conditions)
  • Washable and reusable oil-free filter media
  • AEM Lifetime Limited Warranty


The AEM 21-735WR fits some Subaru Impreza WRX STi, Subaru WRX, and Subaru WRX STI models.

The AEM 21-735WR Performance Cold Air Intake System produces horsepower and torque gains by replacing your vehicle’s restrictive factory air filter and air intake housing. This air intake system was designed, tuned and dyno-tested to fit specific Subaru WRX STI models. Air enters the system through an oversized AEM Dryflow synthetic washable air filter for outstanding air flow, filtration and performance. The air filter is located in the original air box space and is protected by a heat shield which is designed to reduce intake air temperature and increase horsepower. The intake tubing is constructed from mandrel-bent aluminum featuring a durable textured red powder coated finish. This air intake system was developed to accommodate the engine’s factory emissions control devices including the mass air flow sensor. The tapered cylinder shaped AEM Dryflow air filter is made from an oil-free, synthetic filter media that can be used for up to 100,000 miles before cleaning is needed (depending on driving conditions). The air intake system is easy to install with commonly available tools and it is backed by AEM's Lifetime Limited Warranty. Some AEM air intakes are not legal for sale or use in California and other states adopting California emission standards while others are 50 state legal. View the 21-735WR vehicle applications to determine the legal status for each vehicle. 


AEM 21-735WR Product Specifications
Replacement Filter 21-2029D
Air Filter Color Red
Air Filter Material Non-woven Synthetic
Air Filter Outlet Shape Round
Clamps Included 3
Clamp Material Stainless Steel
Clamp Style Regular
Couplers Included None
Product Style AEM Cold Air Intake System
Air Filter Height 9 in (229 mm)
Intake Pipe Color / Finish Wrinkle Red
Intake Pipe Material Aluminum
CARB EO Number D-670-24
Street Legal In All US States See Application Link Above
TUV Approved (Europe) No
Weight 8.9 lb (4 kg)
Product Box Height 12.25 in (311 mm)
Product Box Length 20.25 in (514 mm)
Product Box Width 12.25 in (311 mm)