The S476 turbo is a BorgWarner S400-frame turbocharger built around a 76 mm compressor inducer — that single measurement is what distinguishes it from every other S400-series variant and gives it its name. While the broader 75–76 mm compressor class includes several configurations across different frame sizes, this page focuses exclusively on the 76 mm S400-frame setup: its wheel specs, turbine housing options, oil drain fitment details, and the True North Turbos S476 76mm T4 available directly through Black Sheep Industries.

If you already know you want a BorgWarner S476 in the S400 frame, you're in the right place. If you're still weighing the 75 mm option, the S475 sibling page covers that compressor wheel in the same frame depth.

The 76 mm T4 configuration has become the standard starting point for serious diesel performance builds — particularly on 5.9 L and 6.7 L Cummins platforms — because T4 turbine housings are widely available in the aftermarket, the bolt-on fitment is well understood, and the S476 strikes a practical balance between spool response and top-end airflow for builds chasing four-figure horsepower. The True North Turbos S476 76mm T4 is Black Sheep Industries' direct offering in this category, and it's the most common single turbo starting point in the store for a reason.

S476 Turbo Specs: Compressor, Turbine & Frame Details

Understanding the s476 turbo specs means separating three distinct categories: what the compressor wheel does, what the turbine side contributes, and how the S400 frame itself dictates physical fitment. Each layer matters independently when you're sourcing parts or verifying compatibility.

Compressor Wheel Specs

The defining specification of any S476 is its 76 mm compressor inducer. Everything else — housing selection, turbine pairing, A/R ratio — builds outward from that number.

The compressor exducer on S476 variants typically falls in the 102–105 mm range, though the exact figure varies depending on the compressor map in use. This is an important caution: aftermarket S476 compressor configurations are not all cut from the same map, and exducer dimensions can shift meaningfully between suppliers. Before ordering a matched compressor housing or making airflow assumptions, verify the specific exducer against BorgWarner documentation or the TNT476 supplier data sheet. The 76 mm inducer, however, is universal across any legitimate S476 — it is the identifying dimension, and it's where the S400-frame S476 earns its name.

Turbine Wheel Specs

On the turbine side, common aftermarket S476 builds use wheels in the 80–83 mm inducer / 74–76 mm exducer range, though these figures are not locked to a single universal spec. Turbine wheel selection influences three things that matter enormously in a high-power diesel build: spool characteristics, drive pressure ratio, and exhaust gas temperature under load.

A smaller turbine inducer responds faster but builds drive pressure more aggressively at peak flow. A larger wheel reduces backpressure at high airflow but asks for more exhaust energy before it wakes up. The key point is that the turbine-side configuration you pair with the 76 mm compressor wheel shapes the real-world behaviour of the turbo as much as the compressor wheel itself does. Avoid assuming that a single turbine spec applies across all S476 builds — it doesn't.

S400 Frame Fitment Basics

The S476 sits in BorgWarner's S400 large-frame architecture. This distinction has direct, practical consequences when you're ordering oil drain flanges, and it's where builders often run into preventable fitment errors.

The oil drain bolt centre on an S400-frame turbo measures 50.8 mm (2.00 in). The mid-frame equivalent measures 50 mm (1.97 in) — a difference of just 0.8 mm, or roughly 1/32 of an inch. That gap is small enough to cause a misidentified order and large enough to create a fitment problem on the build. Use calipers on your existing hardware before ordering a drain flange rather than trusting visual identification alone. The S400 turbo guide covers frame-level context in greater depth if you need a broader reference before choosing an S476.

S476 Turbo Horsepower Range

The s476 turbo horsepower capability, as documented for the True North Turbos S476 76mm T4, spans 1,110–1,230 HP at the crank. That range reflects the operating envelope of the 76 mm compressor in this S400-frame configuration under real-world diesel performance conditions.

For most builders working in the 1,000–1,100 HP bracket, either the S476 or its 75 mm sibling can get the job done — the one-millimetre inducer difference doesn't become decisive until airflow demand pushes beyond roughly 1,150 HP crank. Above that threshold, the extra inducer area on the S476 begins to reduce choke margin in a meaningful way, giving the 76 mm wheel an advantage in top-end flow that the S475 can't fully replicate.

The s476 turbo Cummins pairing is probably the most common application in this horsepower range. The 5.9 L and 6.7 L Cummins platforms have well-established manifold and downpipe solutions for the 76 mm T4 configuration, and the documented crank horsepower range aligns well with where performance Cummins builds tend to land when they outgrow single mid-frame turbos but aren't yet chasing compound setups.

S476 vs S475: What Actually Changes?

The s476 vs s475 debate generates more forum posts than it deserves. The real differences are specific and modest. The marketing language around them is often neither.

Compressor Inducer Difference

The S475 uses a 75 mm compressor inducer. The S476 uses a 76 mm compressor inducer. That single millimetre is the root of every functional difference between the two turbos when turbine side, compressor housing, and frame are otherwise identical.

In practical terms, the larger inducer on the S476 yields roughly 3–5% more mass air at equivalent conditions. That's a real difference — it shows up in compressor map comparisons and matters at high demand — but it is not the dramatic performance chasm that some product descriptions imply. If a build is targeting 1,000–1,150 HP and the rest of the hardware is the same, many experienced builders treat the two wheels as interchangeable.

Spool and Peak Flow Trade-Off

The S476 typically offers marginally higher peak airflow capacity, which is exactly what the 3–5% mass air advantage would predict. The corresponding trade-off is slightly later spool compared with an S475 in an otherwise identical setup. The larger inducer needs marginally more exhaust energy to begin moving meaningful air.

For engines targeting 1,000–1,200 HP where both turbos theoretically fit the compressor map, the spool difference is modest and may be negligible depending on turbine-side selection and boost strategy. The practical recommendation is to choose based on where in that range your build will actually operate day-to-day rather than on peak numbers alone.

When the S476 Makes More Sense

The S476 earns its advantage above approximately 1,150 HP crank. At that level of airflow demand, the extra inducer area starts to reduce choke margin — the margin between your operating point and the edge of the compressor map — in a way the S475 cannot match with an identical housing. If your build is targeting the upper end of the four-figure range or beyond, the S476 is the right wheel.

For builds that sit comfortably below 1,150 HP with room to spare, the S475 may offer slightly better response without sacrificing meaningful top-end headroom. The S475 page covers the 75 mm compressor wheel in the same detail this page applies to the S476 — compare both before committing if your target horsepower lands in the middle of the overlap zone.

Best Turbine Housing A/R for an S476 T4

Turbine housing selection is where the s476 t4 setup gets personalised to the build. The compressor wheel is fixed once you've chosen the S476; the housing A/R ratio is the primary tuning lever left on the turbine side.

1.10 A/R for Quicker Spool

A 1.10 A/R housing is the standard recommendation for street and strip diesel applications where response matters as much as peak flow. The tighter housing builds exhaust velocity more quickly at lower RPM, waking the 76 mm compressor wheel sooner and keeping drive pressure at manageable levels on builds in the 1,100 HP range. If the turbo needs to pull hard from a rolling start or deliver boost early in the RPM range for track passes that aren't purely top-end, 1.10 is the more useful starting point.

1.25 A/R for Higher-Flow Builds

At 1,200+ HP crank, the 1.10 A/R housing can become a restriction — drive pressure builds more aggressively than necessary and exhaust gas temperatures climb at sustained high flow. A 1.25 A/R housing opens the turbine scroll, allowing exhaust gases to flow more freely, which reduces both drive pressure ratio and EGT under load. The trade-off is a delayed spool response compared with the 1.10. For all-out competition builds or applications where peak power is the priority and low-RPM response is less critical, the 1.25 delivers better conditions at the top of the power range.

T4 Divided vs T6 Divided Housing Options

T4 divided turbine housings are the dominant choice for S476 diesel performance applications, and for good reason: they're widely available in both 1.10 and 1.25 A/R, they fit within common manifold and downpipe configurations, and the aftermarket support around them is mature.

T6 divided housings exist for builders who need higher turbine flow capacity than the T4 platform can provide, and they suit certain extreme-output or compound-turbo configurations. The practical downsides are real: T6 setups introduce additional packaging constraints in most engine bays, the larger inlet flange requires a different manifold or adapter, and the housing geometry tends to delay spool relative to a comparable T4 setup. Unless the application specifically demands T6 flow capacity, T4 remains the more practical and better-supported choice for the 76 mm S400 setup.

T4 vs T6 on an S400-Frame S476

The T4/T6 designation refers to the turbine inlet flange — the point where exhaust gases enter the turbine housing from the exhaust manifold. This is distinct from the turbine outlet (the exhaust discharge side) and completely separate from the oil drain. Understanding which terminology applies to which component prevents mismatched orders.

T4 Outlet and Flange Notes

On a T4-housed S476, the exhaust outlet uses a 4.62 in (117 mm) half-marmon flange. This flange dimension is shared with the Garrett G-Series 42/45, which means crossover downpipe and clamp solutions that work on those Garrett turbos are often directly compatible — a useful detail for builders running hybrid exhaust systems or sourcing non-turbo-brand downpipes.

The T4 designation itself refers to the turbine inlet flange, inlet gasket, and turbine housing bolt pattern. When a supplier or forum post says "T4 S476," all three of those components are implied by the inlet flange choice.

T6 Outlet and Packaging Notes

A T6-housed S476 uses a 5.75 in (146 mm) full-marmon at the exhaust outlet. The clamp required for this outlet is 99502-0588 — worth confirming before ordering downpipe hardware if you're working with a T6 setup. The larger outlet diameter is part of why T6 housings flow more exhaust gas at peak demand, but it also means the full-marmon connection is bulkier and less forgiving of tight engine bay fitment.

T6 configurations on the S476 are legitimate for high-flow applications, but the packaging considerations are genuine. Plan for both the inlet flange manifold fitment and the outlet clamp and downpipe routing before committing to the T6 path.

Avoiding Bolt Pattern Confusion

A quick terminology note that saves real headaches: "bolt pattern" is the correct term when discussing turbine inlet flanges, inlet gaskets, and turbine housing attachment. It is not the appropriate term for oil drain measurements. The oil drain uses a bolt centre distance — 50.8 mm (2.00 in) for the S400 large frame — which is measured differently and ordered against different specifications entirely.

Turbine inlet flange choice and oil drain fitment are two separate fitment questions that happen to both involve bolts. Keeping the terminology straight prevents ordering errors and makes conversations with suppliers and installers cleaner.

S476 Oil Drain and Fitment Checks

Drain fitment is where many S476 builds hit an unnecessary delay. The measurements are specific, the consequences of ordering the wrong flange are a wasted parts run, and all of this is avoidable with a five-minute caliper check before placing an order.

Oil Drain Bolt Centre Measurement

The S400-frame oil drain bolt centre is 50.8 mm (2.00 in). The mid-frame measurement is 50 mm (1.97 in). The difference — 0.8 mm, or roughly 1/32 of an inch — is small enough that visual identification is unreliable and large enough to guarantee the wrong flange won't seat correctly. Measure the bolt centre on your turbo with calipers before ordering a drain flange, and order against the confirmed dimension rather than an assumed frame designation.

Correct Drain Port Size

The drain port on an S400-frame S476 is 12AN. Using a 10AN fitting here is undersized for this application and can restrict oil return, which creates conditions for oil backing up into the centre housing under sustained boost. This is not a "close enough" substitution — spec the 12AN fitting when sourcing your drain line components.

The s476 turbo Cummins installation in particular tends to generate questions about drain routing on 2nd-gen style setups where clearance to the block face and oil pan rail can be tight. Getting the port size right from the start avoids having to re-plumb after the turbo is in place.

Drain Length Options

Drain length is an independent specification that addresses clearance between the turbo centre housing and the mounting surface or block below — it is separate from both the bolt centre measurement and the port size. Available options are:

• 35 mm (1.38 in)
• 65 mm (2.56 in)
• 100 mm (3.94 in)

Choose the drain length based on the physical clearance in your specific installation, not on any assumed relationship to the other drain specifications. Two builds on the same platform can require different drain lengths based on engine position, pan rail shape, and accessory clearance.

S476 Turbo for Cummins Builds

The s476 turbo Cummins pairing is the most common starting point for performance diesel builds in the S400 large-frame class. The 76 mm T4 configuration fits cleanly into the 5.9 L and 6.7 L Cummins engine bay in most configurations, and the aftermarket support around manifolds, downpipes, and boost plumbing for this combination is mature and well-documented.

That said, a few builder concerns come up consistently and are worth addressing before you commit to the configuration:

Downpipe clearance on 2nd-gen style setups is one of the first questions raised in Cummins forums. The T4 outlet's 4.62 in (117 mm) half-marmon flange fits within the downpipe options designed for S400-frame turbos in this chassis, but the exact downpipe angle and flex section routing depends on specific mounting position and housing orientation. Confirm clearance to the frame rail and transmission before finalising the exhaust side.

Housing choice directly affects spool, which on a Cummins platform under tow load or track use can significantly change the usability of the build. The 1.10 A/R recommendation for response-sensitive applications applies here — if the truck sees mixed use, the 1.10 is generally the more forgiving starting point.

Oil drain flange measurement is just as relevant on a Cummins build as on any other platform. The 50.8 mm (2.00 in) S400 bolt centre and 12AN port size apply regardless of the engine — measure before ordering and spec the correct drain length for your particular chassis clearance.

For a direct s476 t4 starting point on a Cummins build, the True North Turbos S476 76mm T4 is the practical answer: it's the 76 mm S400-frame T4 setup with a documented 1,110–1,230 HP crank range and direct availability through Black Sheep Industries.

True North Turbos S476 76mm T4 at Black Sheep Industries

If you've worked through the specs and confirmed that a 76 mm S400-frame T4 turbo is what your build needs, the True North Turbos S476 76mm T4 is available directly through Black Sheep Industries.

The product is documented at 1,110–1,230 HP crank — a range that maps honestly to where the 76 mm S400 compressor operates in real high-performance diesel applications rather than inflated marketing figures. It's the most common single-turbo starting point in the BSI store, and it's positioned there because it represents the right balance of compressor capability, turbine housing availability, and fitment compatibility for the builds this platform is designed to serve.

You can view the full product listing, confirm current pricing, and order directly at:
True North Turbos S476 76mm T4 — Black Sheep Industries

Pricing is in CAD, and Black Sheep Industries covers US duties as part of their North American ordering context — so Canadian and American builders can order from the same product page without duty surprises at the border. For builders south of the border sourcing a quality 76 mm S400 T4 unit, that's a practical advantage worth factoring into the comparison.

If you're not yet certain whether the S476 is the right call or you want to compare it directly against the 75 mm option, visit the S475 page before committing. Both pages are built to give you the data you need to make the call confidently rather than guess at specs that matter on a four-figure-horsepower build.

Quick S476 Buying Checklist

Before you finalise your s476 turbo specs and place an order, run through these four confirmation steps. They won't catch everything, but they cover the fitment errors that show up most often on 76mm turbo builds in the S400 frame.

1. Confirm compressor size

• 76 mm inducer — this is the defining S476 dimension
• Exducer varies by compressor map; verify against supplier documentation before assuming a figure

2. Confirm turbine housing choice

• 1.10 A/R for quicker spool response on street/strip builds to approximately 1,100 HP
• 1.25 A/R for reduced drive pressure and lower EGT on 1,200+ HP applications where top-end flow takes priority

3. Confirm frame and drain fitment

• S400-frame oil drain bolt centre: 50.8 mm (2.00 in) — measure with calipers, do not assume
• Drain port: 12AN — 10AN is undersized for this application
• Drain length (35 mm / 65 mm / 100 mm) is a separate clearance spec; choose based on your chassis

4. Confirm flange and housing terminology

• T4/T6 designations refer to turbine inlet flanges, inlet gaskets, and turbine housings
• T4 exhaust outlet: 4.62 in (117 mm) half-marmon
• T6 exhaust outlet: 5.75 in (146 mm) full-marmon, clamp 99502-0588
• Oil drain bolt centre is a separate measurement — do not apply "bolt pattern" terminology to drain fitment

S476 Turbo FAQ

What is the difference between an S475 and S476 turbo?

The S475 uses a 75 mm compressor inducer; the S476 uses a 76 mm compressor inducer. That one-millimetre difference produces roughly 3–5% more mass air on the S476 at equivalent conditions, at the cost of slightly later spool. When turbine side and compressor housing are otherwise identical, the two turbos are functionally interchangeable on engines targeting 1,000–1,150 HP. The S476 becomes the stronger choice above approximately 1,150 HP, where the larger inducer reduces choke margin in a meaningful way. For detailed 75 mm compressor data, see the S475 page.

How much horsepower can an S476 turbo support?

The True North Turbos S476 76mm T4 is documented at 1,110–1,230 HP crank. This is the range Black Sheep Industries aligns to for their S476 offering. In practice, the S476 begins to show its advantage over the S475 above roughly 1,150 HP, where the additional inducer area provides meaningfully more top-end airflow capacity.

What A/R housing is best for an S476 T4?

For street and strip diesel builds where spool response matters, 1.10 A/R is the standard recommendation and suits builds up to approximately 1,100 HP with manageable drive pressure. For builds targeting 1,200+ HP where peak flow and lower exhaust gas temperatures are the priority, 1.25 A/R reduces drive pressure and EGT at the cost of delayed spool. T4 divided housings are the most widely supported option; T6 divided housings are available for higher-flow applications but add packaging complexity.

What oil drain size does an S400-frame S476 use?

The oil drain port on an S400-frame S476 is 12AN. A 10AN fitting is undersized for this application. The oil drain bolt centre is 50.8 mm (2.00 in) — measure with calipers before ordering a flange, as the mid-frame measurement of 50 mm (1.97 in) is close enough to cause ordering errors on visual identification alone. Drain length (35 mm, 65 mm, or 100 mm) is a separate clearance specification selected based on your specific chassis and mounting configuration.

What is the difference between T4 and T6 on an S476 turbo?

T4 and T6 refer to the turbine inlet flange — the connection between the exhaust manifold and the turbine housing. The T4 inlet uses a different flange pattern than the T6, which determines manifold compatibility, inlet gasket, and turbine housing selection. On the exhaust outlet side, T4 uses a 4.62 in (117 mm) half-marmon flange; T6 uses a 5.75 in (146 mm) full-marmon requiring clamp 99502-0588. T4 is the dominant choice for S476 diesel performance builds due to broad aftermarket housing availability and established manifold fitment. T6 suits higher-flow applications but introduces additional packaging constraints and tends to delay spool onset.