Thinking about giving your WRX a power boost?  A downpipe upgrade might be the answer!  This guide will clear up the confusion and help you find the perfect downpipe for your ride.

What is a downpipe?

Imagine a metal tube connecting your engine's exhaust to the turbocharger. That's the downpipe!  The stock one often has a catalytic converter (cat) that can restrict performance.

Why upgrade?

Aftermarket downpipes often swap the cat for a better flowing unit, or remove it altogether. This smoother exhaust flow can lead to:

More horsepower (15-20hp, but it can vary) - A nice power gain to feel the difference!

Better exhaust flow - Your engine breathes easier, potentially improving performance.

WRX Downpipe Fitment Fun Facts!

06/07 WRX: These guys have a unique exhaust system. You'll need a "long" downpipe to connect to the rest of your setup.

08/09 WRX: These models share a downpipe design with the Legacy GT. Make sure to specify the "Legacy GT downpipe" when buying.

Downpipe Details Decoded

Material: Stainless steel or mild steel are common choices. Both work well, with stainless steel offering better corrosion resistance.

Design: There are four main designs, but none is definitively "best." The key idea is to separate wastegate gases from exhaust gases for smoother flow.

Cost: Blank plate designs tend to be the most affordable, while other designs usually fall within a similar price range.

DIY Downpipe Debunking

Gutting: Yes, you can remove the cat yourself (like some do with up pipes), but there are other options too!

STi Downpipe: These will fit your WRX, but the power gain won't be significant.

More Downpipe Decisions

High flow cat or catless? Consider emissions regulations and desired performance level.

Pipe diameter? Larger diameters (3.0" or 3.5") are typically only needed for very high horsepower applications.

Length: Some downpipes remove the 3rd cat by being longer.

Flange type: Do your research to ensure compatibility with your existing exhaust components.

The Downpipe Gain Game

There's no clear winner here!  Most downpipes offer similar horsepower gains (within 5hp).

Downpipe Downsides?

Not many!  There have been some rare reports of wastegate issues with specific downpipe designs.

Bonus: Exhaust Pipe Fitment Fun