GrimmSpeed Cold Air Intake Subaru WRX (02-07) WRX STI (04-07) Black or Red

Fitment Information

• Subaru WRX (2002-2007)
• Subaru WRX STI (2004-2007) 

Specs & Features

• Maximum gains of over 13 ft/lbs and 18 hp
• Hybrid Cold Air/Short Ram Design - Combining the advantages and eliminating the negatives of both traditional intake designs
• Air straightener – A key component for accurate and consistent MAF sensor readings.
• Custom reusable high flow air filter - Integrated velocity stack entrance smooths incoming air
• StealthBox Heatshield – Our signature heatshield design which provides cool air while hiding ugly components
• Made in the USA - Right here in Minnesota, in fact
• 40 min Installation - Extremely simple with our written and video guides

Includes everything

• 1x Intake Tube
• 1x High-flow Oiled Filter
• 1x Silicone Hose Coupler
• 1x Heat Shield Assembly
• 3x Hose Clamps
• 2x MAF Flange Screws
• 3x Precut Rubber Sealing Strip
• 3x Airbox to Chassis Bolts

Product Description

It’s no secret that GrimmSpeed intakes feature performance and aesthetics that lead the pack.  With years of design theories and knowledge gained from our successful intake program, we have developed solutions that increase power and are very easy to install and tune.  The only thing we were missing was an intake system for early models, and after nearly two years of development and testing, we are extremely proud to offer what we feel is the best intake for your 2002-2007 Subaru WRX and STI, and 2004-2008 Subaru Forester XT.

Dyno testing was completed on a 2006 WRX, equipped with a GrimmSpeed 3-Port EBCS, Catted Downpipe, EWG Up-Pipe, and TMIC, being force-fed by a VF39 on 91 octanes.

We used a testing methodology to show a difference between how a change to only the intake affects the power output, boost, and air to fuel ratios.  The car was first equipped with a Cobb OTS Stage 2 tune and was modified only for the VF39 and external wastegate.  The airbox was OEM, but with a K&N drop-in filter.  The tune was then verified and ran multiple times for a boost target of 18psi and an AFR of 11:1.  Next, we installed the GrimmSpeed intake and performed a dyno pull.  As expected, the tune was a little too rich, so the tuner adjusted fueling to compensate.  The goal was to make the exact same AFR as our OEM airbox pulls, and the tuner accomplished this in only three total pulls on the dyno.

The result of this pull, with absolutely no changes to the map other than adjustments to match AFR, was an increase in horsepower and torque nearly everywhere in the entire RPM range.  There are maximum gains of over 13 ftlbs and 18 hp, as shown in the chart to the left.  The chart on the right demonstrates that the design of the GrimmSpeed intake system has decreased restriction over the stock system (even with an aftermarket drop in filter).  This chart shows that while the AFRs for the pull are exactly the same, the gains in peak boost have increased by almost .75psi.  Even more important is the increased boost at redline of 1.5psi.  An increase in boost from only the intake change means that it has removed that much restriction from the intake system.  Just looking at the boost curve shows that these relatively small turbos start to run out of breath at higher RPMs, and that the much needed increase in boost that the GrimmSpeed intake creates results in a substantial power gain all the way to redline.