GrimmSpeed Equal Length Exhaust Header – 2015-2021 Subaru WRX

GrimmSpeed Equal Length Exhaust Header , 2015-2021 Subaru WRX

The GrimmSpeed Equal Length Exhaust Header for the 2015-2021 Subaru WRX replaces the factory unequal length manifold on the FA20DIT with a four-into-one equal length design. Equal length primaries eliminate the exhaust pulse interference that limits scavenging efficiency on the stock manifold, producing genuine power gains across the RPM range.

DETAILS

• Equal length primary tubes
• Four-into-one collector
• 304 stainless steel
• Improved turbo efficiency and mid-range power
• Direct bolt-on
• Fitment: 2015-2021 Subaru WRX FA20DIT

The FA20DIT’s factory exhaust manifold uses unequal length primary tubes , a manufacturing compromise that creates exhaust pulse timing conflicts at the turbocharger inlet. The result is inconsistent turbine flow, slower spool, and reduced scavenging efficiency. GrimmSpeed’s equal length design presents the turbine with an optimized, consistent exhaust gas stream.

Power gains are most significant in the mid-range where the factory header’s pulse interference is most impactful. Turbo response improves, throttle feel sharpens, and peak numbers increase across the power band. The 304 stainless construction is rated for the sustained heat that a turbo manifold experiences.

What’s in the Box

• GrimmSpeed equal length header
• Gaskets
• Hardware
• Installation instructions

Why Choose GrimmSpeed

GrimmSpeed has been engineering performance parts for Subaru platforms from their Portland, Oregon facility since 2003. Everything they make is designed around real-world use , their engineers drive the same cars their customers drive, which means product decisions are made with genuine platform knowledge behind them. GrimmSpeed designs parts in-house, sources quality materials, and validates fitment on the actual application before release. The result is parts that install correctly the first time, perform as advertised, and hold up under the conditions Subaru owners actually subject their cars to. Whether it is a critical engine component or a cosmetic upgrade, the same attention to detail and fit quality applies across the catalog.

The RallySport Take

The GrimmSpeed equal length header for the FA20DIT WRX is one of the most effective single performance modifications available for this platform. The factory manifold is a known limitation and this header addresses it correctly. Fits the 2015-2021 Subaru WRX with FA20DIT.

Fitment