GrimmSpeed Downpipe/ J Pipe

The best GrimmSpeed downpipe parts for a Subaru are the ones that match your generation exactly: 3-inch catted downpipes for the 2002-2007 and 2008-2014 WRX and WRX STI, V2 GESI catted versions, and the small adapters and gaskets that let a stock downpipe meet a 3-inch cat-back, or the reverse. Start with your year range here, then add the correct turbo-to-downpipe and downpipe-to-catback gaskets for a leak-free install.

On a turbo Subaru, the downpipe is the first exhaust section after the turbo, so it affects exhaust flow, sound, and how the rest of the system bolts up. This collection mixes complete catted downpipes with supporting hardware, which matters because many exhaust leaks and fitment headaches come from reusing crushed gaskets or mismatching a 3-inch flange to a stock-size one. Adapters solve that junction in both directions, and thicker 2-bolt gaskets are listed for most Subaru turbo models. Check your year and model on every part, because 02-07, 08-14, 15-21, and 22-26 fitments differ.

GrimmSpeed is the single brand here, and downpipes are only one corner of its wider Subaru range. Its catted downpipes in this collection include standard and Limited versions, black ceramic coated options, and V2 GESI catted versions for the 02-07 and 08-15 WRX and WRX STI and the 05-09 Legacy GT. The supporting range is just as characteristic: a turbo-to-downpipe gasket, a universal 3-inch downpipe-to-catback gasket, and a specific turbo-to-downpipe gasket for the 22-26 WRX.

Useful starting points are the adapter from a stock downpipe to an aftermarket 3-inch cat-back, the turbo to downpipe gasket for Subaru turbo models, and the turbo to downpipe gasket for the 22-26 WRX. Our guide to the best downpipe for the 2002-2007 WRX gives generation-specific context.

COBB Tuning is the brand most owners pair with a downpipe change, because its Accessport is the common way Subaru owners check whether their calibration suits new exhaust hardware. Invidia is the other big comparison in this section of the exhaust, with its own downpipe and cat-back range for Subaru platforms. Whichever pipe you choose, plan the gaskets and the tune question together, and browse the 22+ WRX collection if you are shopping for the newest generation.

Does a catted downpipe need a tune?

On most turbo Subaru applications, a downpipe change should be paired with a calibration that supports it. Check the guidance for your exact year and model and your tuning platform before driving hard on a new downpipe.

Why do I need an adapter for a 3-inch cat-back?

A stock downpipe outlet and an aftermarket 3-inch flange are different sizes, so a plain gasket often leaks at that joint. The adapters in this collection step between the two sizes in either direction, stock-to-aftermarket or aftermarket-to-stock.

Should I replace the gaskets with a downpipe?

Fresh turbo-to-downpipe and downpipe-to-catback gaskets are the usual practice, because old gaskets have already crushed to the previous flanges. Matching the gasket to your generation is as important as matching the pipe itself.

What does GESI catted mean on the V2 downpipes?

The V2 listings in this collection are described as GESI catted, referring to the catalytic converter fitted in those versions. Choose between the standard, Limited, ceramic coated, and V2 versions by your generation and the listing details, not by name alone.