“Put this on my M2 and honestly couldn’t be happier. Fitment was good, welds looked tidy and it sounds unreal compared to stock. Valves work well too, so it’s not obnoxious all the time. Open it up and the car sounds heaps better, much deeper and more aggressive. Makes the whole car feel way more alive. Definitely one of the better mods I’ve done.”





WSTN Performance
BMW M135i / M235i / 335i / 435i / M2 Catless Downpipe — N55 3.0T EWG | WSTN Performance
12 Month Warranty
FITMENT GUARANTEE
worldwide shipping
Choose options
12 Month Warranty
FITMENT GUARANTEE
worldwide shipping
12 Month Warranty
FITMENT GUARANTEE
worldwide shipping
Free the N55. Remove the restriction.
Built for the N55-powered F-Series platform — the M135i, M235i, 335i, 435i, and M2 — this catless downpipe eliminates the factory catalytic converter that sits directly downstream of the turbocharger, the single biggest restriction on power and sound in the entire exhaust system. Constructed in 304 Stainless Steel with mandrel-bent piping and precision TIG-welded flanges, every unit is quality checked in Perth before dispatch worldwide. The result: more turbo spool, sharper throttle response, and an exhaust note that does justice to the N55's potential.
Why Upgrade?
✅ Unrestricted Flow: Eliminates the factory cat — the biggest single restriction in the N55 exhaust system — for immediate gains in spool and response.
✅ Acoustic Transformation: The N55 sounds aggressive and purposeful, not muffled and corporate.
✅ Direct Bolt-On: Bolts directly to factory mounting points. No cutting, no welding.
✅ 304 Stainless Steel Construction: Corrosion-resistant, built to handle the heat and pressure of a turbocharged inline six.
Key Features & Specs
Material: 304 Stainless Steel — corrosion resistant, built to last
Diameter: 4-inch / 102mm primary pipe
Construction: Precision mandrel-bent, TIG-welded joints
Finish: Brushed 304 stainless
Fitment & Compatibility
✔️ BMW M135i / M135xi (F20/F21) — 2012–2018 (N55B30, post-07/2013 production)
✔️ BMW M235i / M235xi (F22/F23) — 2013–2018 (N55B30)
✔️ BMW 335i / 335xi (F30/F31) — 2012–2015 (N55B30, post-07/2013 production)
✔️ BMW 435i / 435xi / Gran Coupe (F32/F33/F36) — 2013–2016 (N55B30)
✔️ BMW M2 (F87) — 2015–2018 (N55B30)
EWG (Electric Wastegate) fitment only — fits models produced after 07/2013. For pre-07/2013 M135i or 335i, check production date on your door jamb before purchasing.
Technical Note
Emissions: Catless straight-through — intended for track and competition use. CEL will trigger without ECU tune. Buyer responsible for local emissions compliance.
What's In the Box
1 x WSTN Performance N55 Catless Downpipe
Installation
Difficulty: 3/5 — Requires workshop lift and exhaust experience
Time Estimate: 1–2 Hours
Mounting Type: Direct bolt-on to factory turbo outlet flange (EWG models)
Warranty / Shipping
DISCLAIMER
WSTN Performance components are designed for track and competition use. To protect your build and ensure a perfect finish, we recommend professional installation by a certified specialist/workshop. It is the buyer's responsibility to ensure modifications comply with local regulations.
WARRANTY
We stand behind every product we sell. All WSTN Performance products carry a 1 year WSTN Performance warranty as standard. This covers any manufacturing defects, giving you total peace of mind that your upgrade is built to last. View our full Warranty policy page here.
SHIPPING
We offer tracked worldwide shipping on our entire catalogue. Products marked as “Built to Order” are handmade in 3–5 weeks (check the product page as lead times may vary), quality checked and sent from Perth WA. View our full Shipping policy page here.
RETURNS
We offer returns on all products if items are damaged or there is something wrong. If we ever make a mistake, we'll cover the return shipping to make it right. View our full Return policy page here.
SUPPORT
Need a hand with fitment, shipping, or a return? Our Perth-based team is here to help you get your build perfect.
Email: contact@wstnperformance.com
Sound Clip
From real
Builds and drivers
4.9
Avg rating
How every order gets built
Crafted
for your
exact build.
Every exhaust and downpipe is built to your vehicle and engine code.
Flanges are CNC machined to match your OEM mounting points. Pipe diameter, bend angles, and hanger positions are set from your chassis spec before anything is cut. No guesswork, no transfers from a similar build.
01
Order placed
Your build is locked in and production begins against your specific vehicles engine code and chassis.
02
Mandrel bent, TIG welded
T304 stainless or Titanium alloy formed to spec. Every join TIG welded by hand for clean, consistent strength.
03
Quality checked
Every unit is personally inspected against fitment specs before it it is shipped.
04
Shipped and tracked
Dispatched via DHL, FedEx, UPS with full tracking. You'll know exactly where your order is.
What stays consistent
T304
Stainless steel
Heat-resistant, corrosion-proof, and built for longevity.
TITANIUM
ALLOY
Half the weight of steel. For when performance and weight saving is key.
TIG
Weld process
Every joint fused by hand. Clean, precise beads that hold under sustained heat and pressure.
CNC
FLANGES
Machined to tolerance. Direct bolt on and perfect seals.
Built to order
Every exhaust is built to your engine code - not pulled from a shelf. When you order, production starts by hand. Lead times are listed on every product page.
Support
FAQ
Every system we build is vehicle-specific. If you're unsure, reach out before ordering with your make, model, year, and any relevant modifications or click the "Fitment Check" box on this page - we'll confirm fitment before you spend a dollar.
It depends on what's been changed. upgraded turbo, upgraded mid pipe or prior exhaust modifications can all affect fitment. Our exhaust systems/downpipes are designed to fit vehicles stock, from factory. Contact us with your build details and we'll advise honestly.
We work with premium-grade T304 stainless steel and titanium alloy depending on the application. Material specs are listed on each product page
We're built to the same standard, the same materials, the same fabrication quality, the same attention to fitment and finish. The difference is we're not charging you for a badge. You're paying for the product.
Sound level varies by product, vehicle, and configuration. Where available, we've included sound references on the product page. If you want to know what a specific system sounds like on your car, reach out - we'll point you in the right direction.
A properly designed exhaust system reduces back pressure and improves flow - which typically translates to real performance gains. Our downpipes in particular are designed to let turbocharged engines breathe properly. Specific gains depend on your vehicle and tune.
Road legality varies by state, country, and vehicle. It's your responsibility to confirm compliance with your local regulations before fitting. We can advise on the product side, but we can't make that determination for you.
Items listed and in stock ship in 2-3 days. Hand built to order lead times vary by product and are listed on each product page. We'll send you an update at each stage so you're never left wondering where things are.
Yes - we ship worldwide via DHL, FedEx, UPS, and Australia Post depending on your location. Shipping options and estimated costs are shown at checkout.
Reach out before ordering and we'll tell you exactly where things stand and if we can put priority on your build. We'll always be upfront about timeframes.
We strongly recommend having your system fitted by a qualified workshop, particularly for vehicles where warranty or road compliance is a consideration. A professional install also protects the quality of the finished product and ensures proper fitment.
Yes - all necessary hardware is included unless stated otherwise. Some exhausts and downpipes use your cars existing hardware. If anything is missing from your order, contact us immediately and we'll sort it out.
In many cases, yes. Contact us with what you're after and we'll let you know what's possible and what it'll cost.
Contact us directly. We stand behind what we build. If something isn't right, we'll make it right - no runaround.
Yes. Warranty details are outlined in our warranty policy. If you have a specific question about coverage on a particular product, get in touch before you order.
Because every product is built to order, we can't accept returns for change of mind. That's why we strongly encourage you to confirm fitment with us before purchasing - we'd rather sort that out upfront than after the fact.




