BORG WARNER 178787 S400SX TURBINE HOUSING 87MM .90 A/R T4

Product Description

BorgWarner S400SX turbine housing .90 A/R T4, S400 turbo housing 178787, twin-scroll volute, high-flow diesel turbo parts, AirWerks S400 performance, CPP Diesel BorgWarner housings, faster spool, lower drive pressure, 6.7 Cummins 2nd-gen swap compatible hardware

Unlock crisp spool and strong top-end with the BorgWarner 178787 S400SX Turbine Housing. Sized for the 87mm S400 turbine and engineered with a twin-scroll .90 A/R T4 volute, this genuine AirWerks housing is a proven match for street/strip single S400 builds and compound setups that demand fast response without choking the top end. Cast-iron construction stands up to heat and abuse, while the divided T4 inlet helps stabilize drive pressure and improve cylinder scavenging.

Fitment & Use

• Turbo Family: BorgWarner S400 / S400SX / AirWerks
• Turbine Wheel: 87mm (S400)
• Inlet: T4 divided (twin-scroll)
• Typical Applications: Single S400 street/strip builds, 2nd-gen swap setups, compound turbo low-pressure chargers where .90 A/R T4 response is desired

Cross-Reference / Alternatives (BorgWarner on CPP Diesel only)

• BORG WARNER 178788 — S400SX 87MM 1.00 A/R T4
• BORG WARNER 178789 — S400SX 1.10 A/R T4
• BORG WARNER 178790 — S400SX 87MM 1.25 A/R T4
• BORGWARNER 177102 — S400 83MM 0.90 A/R T4
• BORGWARNER 177104 — S400 83MM 1.10 A/R T4

FAQ

Will .90 A/R T4 choke my top end on an 87mm S400?

For most street/strip S400 builds the .90 A/R twin-scroll offers excellent response with strong top-end. If you’re running sustained high RPM or big fuel, consider the 1.00–1.25 A/R options linked above.

Is this housing divided (twin-scroll)?

Yes. It uses a divided T4 inlet to help pulse separation and reduce drive pressure in properly matched manifolds and piping.

What turbine wheel does it fit?

It’s sized for the BorgWarner S400 87mm turbine wheel.

Does it include hardware or clamps?

No. This is the housing only. Retain your hardware or source BorgWarner-compatible hardware separately.

Specifications for BORG WARNER 178787