If you’re modifying your turbocharged BMW, upgrading the n55 downpipe is one of the most impactful first steps. At Rvng RaceWorks, we specialize in performance parts that extract maximum gains from your platform while maintaining reliability. Whether you’re after more horsepower, a better exhaust note, or quicker spool times, an N55 Downpipe delivers all that and more. But choosing between a catted N55 Downpipe and a catless N55 Downpipe can be tough. This guide will help you understand both options so you can make the right decision for your build.
Why Upgrade the N55 Downpipe?
The stock N55 Downpipe is restrictive due to its OEM catalytic converter. This bottleneck limits power and increases turbo backpressure. Replacing it with a performance N55 Downpipe opens up exhaust flow, allowing your turbo to spool faster and your engine to breathe freely. The result? More power, better throttle response, and a much more aggressive sound.
At Rvng RaceWorks, we offer both catted N55 Downpipes and catless N55 Downpipes, depending on your goals. Both options provide gains, but they do so with different trade-offs.
Catted N55 Downpipe – Best of Both Worlds
A catted N55 Downpipe includes a high-flow catalytic converter, allowing you to maintain emissions compliance while still gaining performance. The catted version is ideal for those who want:
- A CEL-free experience with proper tuning
- Improved flow over stock without excessive smell
- Slightly quieter exhaust tone compared to catless
Our Rvng RaceWorks catted N55 Downpipe uses a premium high-flow cat designed to minimize restriction while filtering exhaust gasses. It’s the ideal choice for street-driven builds that still want real power gains.
Catless N55 Downpipe – Maximum Performance
If you’re going for all-out performance, a catless N55 Downpipe is the way to go. This version eliminates the catalytic converter altogether, resulting in:
- Maximum exhaust flow
- Quicker turbo spool
- Louder and more raw exhaust note
- Reduced backpressure
However, a catless N55 Downpipe will likely trigger a CEL (check engine light) unless tuned properly. It’s also not emissions legal in many regions. For dedicated track builds or off-road applications, though, this setup unleashes the full potential of your N55.
Sound Comparison – Catted vs Catless N55 Downpipe
One of the most noticeable changes after installing an N55 Downpipe is sound. A catted N55 Downpipe deepens the tone but retains a more refined character. A catless N55 Downpipe, on the other hand, delivers a louder, raspier, and more aggressive growl.
At Rvng RaceWorks, we test all our N55 Downpipe options to ensure you’re getting the right tone and performance balance for your build. Whether you’re pairing it with a stock exhaust or a full system, we can dial in the sound you’re after.
Tuning After Installing an N55 Downpipe
Anytime you install an N55 Downpipe, proper tuning is recommended. A tune will:
- Optimize air/fuel ratios
- Prevent CELs from cat efficiency codes
- Increase horsepower gains
- Improve drivability and fuel economy
At Rvng RaceWorks, we can recommend tunes that pair perfectly with your new N55 Downpipe, whether catted or catless. The right tune ensures reliability and gets you the most out of your setup.
Which N55 Downpipe Is Right for You?
It all depends on your goals:
- Street-friendly daily driver? Go with our catted N55 Downpipe.
- Track-only build or want maximum power? Choose the catless N55 Downpipe.
- Concerned about emissions or smell? Stick with the catted version.
- Need the loudest sound possible? Catless is your answer.
No matter your choice, every N55 Downpipe from Rvng RaceWorks is made from premium stainless steel, TIG-welded for strength, and tested under extreme conditions. We design our products with fitment and long-term reliability in mind.
Final Thoughts on the N55 Downpipe Upgrade
Upgrading your N55 Downpipe is one of the best mods for any turbocharged BMW powered by the N55 engine. Whether you go with a catted N55 Downpipe or a catless N55 Downpipe, the performance improvements are immediate. At Rvng RaceWorks, we back all our N55 Downpipe offerings with expert support, precision engineering, and real-world testing. Your build deserves the best, and our N55 Downpipe lineup delivers just that.