GrimmSpeed 7-Layer Uppipe-to-Turbo Gasket – Subaru WRX / STI / Legacy GT | EJ | 024001

For Subaru EJ-platform WRX, STI, and Legacy GT. 7-layer MLS construction — a genuine upgrade over the OEM single-layer gasket. Single gasket. Replace any time the uppipe-to-turbo flange is separated.

GrimmSpeed 024001 7-layer multi-layer steel (MLS) uppipe-to-turbo gasket for the Subaru EJ-platform WRX, STI, and Legacy GT. One of the most commonly replaced gaskets on the EJ platform — the OEM uppipe-to-turbo gasket is a known weak point under boost and heat cycling. GrimmSpeed’s 7-layer MLS construction delivers significantly higher resistance to blowout and leak compared to the OEM gasket, making it the go-to replacement for any uppipe or turbo service. 0.15 lbs. Ships fast across Canada and the US.

What Is the Uppipe-to-Turbo Gasket

Subaru’s horizontally-opposed (boxer) EJ engine routes exhaust from both cylinder banks into an “uppipe” — a crossover/collector pipe that combines both exhaust streams and routes them upward to the turbo’s turbine housing inlet. The uppipe-to-turbo gasket seals the flanged joint between the uppipe outlet and the turbo turbine housing inlet. This interface is a critical exhaust sealing point that sits under sustained heat load and is subject to exhaust pressure pulses from the engine. A failed or degraded gasket here causes an exhaust leak at the turbo inlet: symptoms include a ticking or blowing noise under load, reduced turbo spool efficiency, and exhaust odour in the engine bay.

7-Layer MLS — Upgrade Over OEM

The GrimmSpeed 024001 uses a 7-layer multi-layer steel (MLS) construction — significantly more robust than the OEM Subaru uppipe-to-turbo gasket. MLS gaskets use multiple thin stainless steel layers (with embossed sealing beads and elastomer coatings on the outer faces) to distribute clamping load more evenly, conform to minor flange surface irregularities, and resist blowout under high exhaust pressure and thermal cycling. Seven layers provide a gasket that can withstand the elevated boost pressures and heat cycles of a modified EJ platform — where OEM gaskets are frequently the first to fail after a tune or power upgrade. This is not just an OEM replacement — it is a meaningful upgrade in sealing reliability, particularly for boosted and tuned EJ builds.

Most Common Replacement Scenarios

The uppipe-to-turbo gasket is replaced most frequently during: aftermarket uppipe installation (the OEM EJ uppipe contains a catalytic converter that restricts flow and is a common boost leak source — replacing it with an aftermarket catted or catless uppipe is a standard EJ modification), turbo removal or upgrade, and any service where the uppipe-to-turbo flange is separated. Best practice: always replace this gasket rather than reusing the old one after the flange is broken. A used MLS gasket that has been heat-cycled may not re-seal reliably.

EJ Platform Fitment — 2002+

Fits Subaru EJ-platform vehicles: WRX (EJ205 / EJ255, 2002–2014), WRX STI (EJ257, 2004–2021), and Legacy GT (EJ255, 2005–2009). All share the same uppipe-to-turbo flange interface on the EJ architecture. Note: the 2015–2021 WRX uses the FA20DIT engine (different architecture, different uppipe and gasket) and is not covered by this gasket.

Single gasket. EJ platform only — not for FA20DIT WRX. Do not reuse after flange separation. Replace any time uppipe or turbo is removed.

Specifications

• Brand: GrimmSpeed
• Part Number: 024001
• Type: Uppipe-to-turbo gasket
• Construction: 7-layer MLS (multi-layer steel)
• Sold as: Single gasket
• Application: Subaru EJ WRX (2002–2014), STI (2004–2021), Legacy GT (2005–2009)
• Weight: 0.15 lbs