BORGWARNER 177105 S400 EXHAUST HOUSING — 83MM T4 1.25 A/R (HALF-MARMON 4.62")

Product Description

BorgWarner 177105 S400 Exhaust Housing — 83mm Turbine, T4 Twin-Scroll, 1.25 A/R
This genuine BorgWarner AirWerks S400 housing is the go-to upgrade when you want lower drive pressure and big-rpm flow from an 83mm turbine on a T4 divided manifold. Cast-iron durability, twin-volute efficiency, and a 4.62" half-Marmon outlet make it a proven choice for high-power single S400s or as the atmospheric charger in compound setups.

BorgWarner 177105, S400 exhaust housing, 83mm turbine housing, T4 twin scroll, 1.25 A/R, AirWerks S400SX, S400SX3, S400SX-E, half Marmon 4.62 outlet, diesel performance turbo parts, CPP Diesel BorgWarner housings

• Frame: S400 / AirWerks
• Inlet: T4 divided (twin-scroll)
• A/R: 1.25
• Wheel Fitment: 83mm S400 turbine
• Outlet: 4.62" half-Marmon (V-band)
• Material: High-silicon cast iron

Fitment & Use

Designed for BorgWarner S400/SX builds using an 83mm turbine wheel with a T4 divided manifold. Typical applications include high-horsepower single S400s and S300/S400 compound (atmospheric) setups where stronger top-end flow is desired. Verify turbine wheel size, inlet flange, and outlet connection before purchase.

Cross-Reference / Alternatives (BorgWarner on CPP Only)

• BORGWARNER 177102 — 83mm, T4, 0.90 A/R
• BORGWARNER 177103 — 83mm, T4, 1.00 A/R
• BORGWARNER 177104 — 83mm, T4, 1.10 A/R

What’s Included

Exhaust/turbine housing only. Turbocharger, clamps, studs, and gaskets sold separately.

FAQ

Will this housing fit any S400?
It fits S400/SX frames that use an 83mm turbine wheel and a T4 divided inlet. Always verify wheel size and outlet style before ordering.

How does 1.25 A/R behave?
The larger A/R reduces drive pressure and supports higher peak flow (great for upper-RPM power) at the cost of later spool compared with smaller A/R options.

What outlet clamp do I need?
This housing uses a 4.62" half-Marmon turbine outlet. Match your V-band clamp and downpipe accordingly.

Is this CARB legal?
No. This performance part is generally not CARB-exempt for on-road use in California. See Proposition 65 info below.

Specifications for BORG WARNER 177105