Tomioka Racing

For a turbo Subaru or EVO build, the best Tomioka Racing (TR) upgrades are the ones that unlock power efficiently: a twin-scroll high-flow downpipe frees up exhaust flow on 2008-2014 WRX and 2008-2018 STI models, while the TD05-18G turbo is the natural next step when the stock turbo runs out of breath. A TR silicone turbo inlet hose rounds out the package by smoothing airflow into the compressor.

A downpipe connects the turbo to the rest of the exhaust; going high-flow and catless reduces backpressure right where the turbo spools, which sharpens response and lets a tune extract more power. A turbo upgrade like the TD05-18G moves more air than the factory unit — that's how you make real gains beyond bolt-ons — but it must be paired with a proper tune, fueling headroom, and supporting mods. See Performance Turbochargers for the broader turbo catalog, Performance Intercoolers for the supporting cooling side, and Engine Management Systems for the tuning hardware you'll need.

Fitment matters more here than in most categories: twin-scroll turbos need twin-scroll downpipes, and flange styles differ by chassis. Check the product's stated year range and turbo flange against your car before ordering — when in doubt, check your year and model.

About Tomioka Racing

Tomioka Racing (TR) is the performance brand behind this collection, focused on forced-induction hardware for Subaru and Mitsubishi platforms. The lineup centers on twin-scroll downpipes for GD and GR/GV chassis Subarus (2002-2007 and 2008-2014 WRX, 2004-2018 STI), the TD05-18G turbo upgrade with flange outlet for 2008-2014 WRX, 2009-2013 Forester XT, and 2005-2009 Legacy GT, plus silicone turbo inlet hoses and — for EVO X owners — 4B11 exhaust manifolds and replacement turbo line kits. If you're building around more boost, TR covers the turbo system end to end.

Popular picks

Start with the TR twin-scroll high-flow catless downpipe for 2008-2014 WRX / 2008-2018 STI, the TR TD05-18G turbo, or the TR silicone turbo inlet hose — and read why you should use our aftermarket exhaust systems for the exhaust side of the build.

Frequently asked questions

Do I need a tune with a downpipe or turbo upgrade?

Yes — both change how the engine breathes, so a proper tune is required to run them safely and actually see the gains.

Will a twin-scroll downpipe fit my car?

Only if your turbo is twin-scroll. Check the downpipe's stated year range and flange against your setup before ordering.

Is catless legal in my state?

Catless downpipes are generally for off-road or track use. Check your local emissions regulations before running one on the street.

What supporting mods does a TD05-18G need?

At minimum a tune, an upgraded intercooler, and enough fuel system headroom. Check your year and model's typical build path.