S200/S300 Turbine Discharge — Marmon Flange

Stop hunting across the border for a turbine discharge that actually fits — BSI Inc. has you covered with a purpose-built S200/S300 turbine discharge Marmon flange, available domestically and priced to compete.

Features & Benefits

• Direct S200/S300 Fitment — Designed specifically to mate with S200 and S300 turbine housings, so you spend less time test-fitting and more time building.
• 4.25" Marmon Flange Connection — The industry-standard Marmon-style interface delivers a leak-free, concentric seal at the turbine outlet, keeping exhaust gases where they belong and holding up under high-heat cycling.
• Flange and Quick-Release Clamp Together — Sold as one part number, so the joint is right on the first assembly rather than assembled from two suppliers' tolerances. No sourcing a clamp separately and hoping it matches.
• Clean Turbine-to-Downpipe Transition — Whether you're routing to a custom downpipe or integrating into an existing exhaust system, this flange gives you a solid, reliable starting point for a professional-grade exhaust transition.
• Built by BSI Inc. — Manufactured by Black Sheep Industries, the same team behind True North Turbos. You're getting a component engineered to work in the same performance ecosystem — not a generic import with questionable tolerances.
• No Cross-Border Hassle — Ships domestically across North America from a Canadian facility, which means no brokerage surprises, no exchange-rate guessing games, and faster delivery for Canadian builders in particular.
• Straightforward Installation — Designed for weld-on fitment into your build, keeping the install process clean and customisable for your specific application.

Check Your Size Before Ordering

S200 and S300 turbine housings use a 4.25" marmon discharge. The S400 T4 uses a 4.62" (117mm) half marmon and the S400 T6 uses a 5.75" (146mm) marmon. The 4.25" and 4.62" are close enough to look identical in a photograph and are often described simply as "marmon" — but they will not clamp together. If you are stepping down from a 400-frame turbo or buying used hardware, measure the turbine housing outlet before you order.

When the rest of your build deserves quality hardware, don't let the discharge flange be the weak link — this is the piece that ties your turbine housing to your exhaust system with confidence.

FAQ

What turbo housings is this turbine discharge flange designed for?

It is designed specifically to mate with S200 and S300 turbine housings.

What connection does this flange use?

It uses a 4.25" Marmon flange connection with a Marmon-style interface at the turbine outlet.

Does it come with a clamp?

Yes. The flange and its quick-release clamp are sold together as one part number, so the joint is correct on the first assembly.

Will this fit an S400?

No. S400 T4 turbos use a 4.62" (117mm) half marmon and S400 T6 turbos use a 5.75" (146mm) marmon. Neither will clamp to a 4.25" flange despite looking similar. Measure the turbine housing outlet before ordering.

Is this flange intended for weld-on installation?

Yes. It is designed for weld-on fitment into your build, keeping the installation clean and customisable for your specific application.

Where does it ship from?

It ships domestically across North America from a Canadian facility, helping Canadian builders avoid brokerage surprises and exchange-rate guessing games.