Invidia Catted Downpipe for 17-21 Honda Civic Type R

Invidia Catted Downpipe (HS17CTRDPC) - 2017-2021 Civic Type R (FK8)

The downpipe is the first thing the turbo exhales into, and the factory FK8 unit restricts flow right where you least want it. This Invidia catted downpipe opens that up with a 76mm pipe and a stainless bellmouth, which means the turbo works less to make the same boost, or more boost for the same effort once you tune for it. It's a one-piece bolt-on with a catalytic converter retained.

Why The Downpipe Matters More Than It Looks

Worth understanding, because it explains where the gains come from.

Exhaust leaves the turbo and immediately hits the downpipe. If that pipe is restrictive, exhaust backs up against the turbine, which makes the turbo work harder to spin and slows how quickly it spools.

Opening the downpipe reduces that backpressure at the source. The turbine spins more freely, which means faster spool and a turbo that isn't fighting its own exhaust to make boost. That's why a downpipe is one of the more meaningful single changes on a turbo car, more so than a section further back.

The bellmouth design matters here too. A smooth, gradual transition from the turbo outlet into the pipe flows better than an abrupt one, which is exactly the spot where the factory setup chokes.

It Keeps The Catalytic Converter

This is the "catted" part, and it's a deliberate middle ground.

A catless downpipe flows marginally more but comes with real drawbacks: a persistent exhaust smell, likely emissions codes, and no chance of passing inspection anywhere that tests.

This retains a high-flow catalytic converter, so you get most of the flow benefit while keeping the car far more livable. It's still not CARB legal, but it's a considerably more sensible daily driver choice than going catless.

Where The Gains Actually Show Up

Honest framing on what to expect.

You'll feel quicker spool and a harder midrange even on an otherwise stock car. But the real gains come with a tune, since the ECU can take advantage of the improved flow to make more boost and run more timing where it's safe to.

If a tune is in your plans, the downpipe is one of the parts that makes that tune worth more. If it isn't yet, you'll still feel the difference, just not the full potential.

One-Piece, Bolts Straight In

The single-piece layout keeps installation simple. No extra joints to align, no sections to fight, and it mates directly to either a factory Type R exhaust or an Invidia catback without adapters.

Stainless construction throughout, which handles the heat cycles and road exposure a downpipe sees far better than mild steel.

Not CARB Legal

Stating this plainly, because it's a real consideration rather than fine print.

This downpipe is not CARB compliant. In California and other states with strict emissions testing, that matters, and it may prevent the car passing inspection.

Expect more sound and more attention along with the flow. If your area tests emissions, check your local rules before buying rather than after.

Fitment

2017-2021 Honda Civic Type R (FK8), including the 2021 Limited Edition

Part number HS17CTRDPC. 76mm piping.

Who Should Grab This

This is for the FK8 owner who wants the turbo breathing freely at the source, and who's either tuned or heading that way. Catted so it's livable, one-piece so it installs cleanly, and stainless so it lasts. Faster spool, harder midrange, and real gains once you tune for it. Just know it isn't emissions legal, and buy accordingly.

Fits: 2017-2021 Honda Civic Type R (FK8), including 2021 Limited Edition. Part number: HS17CTRDPC. Piping: 76mm. Construction: stainless steel with bellmouth inlet. Catalytic converter: retained (catted). Design: one-piece. Emissions: not CARB legal.