S380 Turbo: Specs, Horsepower & Fitment Guide
The S380 is the largest compressor the 300 frame supports — an 80mm (3.15") inducer for builds that want everything the platform has while staying on 300-frame hardware. It is the frame's airflow ceiling, and buying one well means understanding exactly what that ceiling is for.
Black Sheep Industries builds the True North Turbos TNT380 80mm T4 to order in Canada.
S380 Specs
| Compressor inducer | 80mm (3.15") |
|---|---|
| Compressor wheel | Billet, machined from forged 2618 |
| Turbine wheel | 82x75, billet |
| Turbine inlet | T4 bolt pattern, .88 A/R open or .91 A/R divided |
| Turbine discharge | 4.25" marmon |
| Compressor housing | 4" inlet, 2.5" outlet |
| Bearing | Journal, 360-degree thrust bearing |
| Oil drain bolt centre | 50mm (1.97") — mid frame |
| Max power (crank) | 1,300 HP |
The centre housing carries a boss cast and pre-tapped for a rotor speed sensor, plus a standard 1/8" NPT pressure port.
The S380 is offered with the 82x75 turbine only. At an 80mm compressor size a smaller turbine wheel would cap the whole setup, so the pairing is fixed rather than optional.
Read the Ceiling Honestly
1,300 crank horsepower is what the 80mm compressor will support at the edge of its map — hot, inefficient, and working hard. It is not where we would advise running one.
Our practical crossover to the 400 frame sits around 820 HP, well below this turbo's ceiling. That is a selection threshold rather than a physical limit, but it exists for a reason: past that point a 400-frame turbo makes the same power with less strain, better efficiency and room to grow.
The honest case for an S380 is that you want the top of the 300 frame specifically — earlier response than a 400-frame turbo of equivalent airflow, on 300-frame manifold, downpipe and drain hardware you already own. If you are shopping it because it is the biggest number in the lineup, read the frame comparison before you commit to a manifold.
What the Build Needs
At this airflow the supporting build is a prerequisite, not an option. Fuel system, head studs and transmission all have to be ready — an 80mm compressor on inadequate fuelling makes less usable power than a smaller turbo on adequate fuelling, while still charging the response penalty. A turbo blanket is worth having, and an external wastegate and dump tube are required.
Fitment: What You Need to Order
- T4 manifold — open or divided to match the turbine housing you choose
- 4.25" marmon turbine discharge flange and clamp — available in 3", 3.5" and 4". At the top of the frame a 4" downpipe is the recommendation; restricting the exhaust undoes the reason you bought an 80mm.
- Compressor discharge v-band sized to your charge pipe
- Oil drain flange at 50mm (1.97") bolt centre — 12AN. At this size, oil return is not the place to save money.
- External wastegate and dump tube — see wastegates
Full detail: S300 Turbo Flange Guide and S300 Turbo Oil Drain Guide.
S380 vs the Alternatives
Against the S376: four millimetres of inducer and roughly 90 HP of ceiling. The 376 spools a little earlier; the 380 is the pick when the build genuinely needs maximum frame airflow. Both share the fixed 82x75 turbine pairing and identical fitment hardware.
Against a small S400: this is the real decision at this end of the frame. Stay with the S380 if response matters and your 300-frame hardware is already in place — changing frames means moving the turbine discharge from 4.25" to 4.62" and the drain bolt centre from 50mm (1.97") to 50.8mm (2.00"). Move to the 400 frame if you are chasing the number rather than the response, or have not yet bought the manifold.
Buy the TNT380
- TNT380 80mm T4 — built to order in Canada, billet forged 2618 wheels
- All TNT3R T4 turbochargers
Not sure it is the right size? Send your build details through the Turbo Spec Form.
Related Guides
- S300 Turbo Guide
- What Size S300 Turbo Do I Need?
- S376 Turbo Guide
- S300 vs S400 Turbo
- S300 Replacement Turbo Cross-Reference
Frequently Asked Questions
How much horsepower will an S380 support?
Up to 1,300 crank horsepower — the highest in the 300 frame. Treat it as a compressor ceiling rather than a build target. Around 820 HP is where we would normally move you to a 400-frame turbo, which makes the same power more comfortably.
Is there a direct replacement for an S380?
Yes. The TNT380 is a direct bolt-on replacement for a T4 S380 — the T4 bolt pattern, 4.25" marmon turbine discharge and 50mm (1.97") mid-frame oil drain bolt centre all carry over. A T3 turbo requires a new T4 manifold.
Why is the S380 only offered with the 82x75 turbine?
At an 80mm compressor size a smaller turbine wheel would become the limiting restriction and cap the whole setup, so the pairing is fixed rather than optional.
Should I buy an S380 or move to the 400 frame?
Choose the S380 if you specifically want the top of the 300 frame — earlier response than an equivalent-airflow 400-frame turbo, on hardware you already have. Move to the 400 frame if you are chasing the number rather than the response, or if you have not yet bought the manifold.
What oil drain does an S380 need?
12AN at the 50mm (1.97") mid-frame bolt centre. At the top of the frame the drain is doing real work, and oil leaves a turbo by gravity — there is no such thing as a drain that flows too well.
Power ratings on this page are quoted in crank horsepower (HP). Figures previously published in wheel horsepower (WHP) have been restated using our in-house tested conversion — the hardware and its capability are unchanged.