BORG WARNER 178788 S400SX TURBINE HOUSING 87MM 1.00 A/R T4 (DIVIDED)

Product Description

BORG WARNER 178788 S400SX TURBINE HOUSING — 87MM • 1.00 A/R • T4 DIVIDED

The genuine BorgWarner 178788 turbine housing is the go-to 1.00 A/R option for S400SX builds that need crisp response without choking top-end power. It features a T4 divided (twin-scroll) inlet to keep pulse energy high and a proven Half Marmon 4.62" outlet for easy downpipe mating. Built from high-quality cast iron for durability under heat and load, this housing pairs perfectly with the 87mm S400 turbine wheel.

BorgWarner 178788, S400SX turbine housing, S400 87mm 1.00 A/R, T4 twin scroll divided volute, half Marmon 4.62 outlet, AirWerks S400 parts, diesel turbo upgrades, CPP Diesel BorgWarner

Fitment & Notes

• Turbo Series: BorgWarner AirWerks S400 / S400SX
• Turbine Wheel Size: 87mm (S400)
• Inlet: T4 divided (twin-scroll)
• Outlet: Half Marmon 4.62"
• A/R: 1.00
• Material: Cast iron turbine housing

Cross-Reference / Alternatives (BorgWarner on CPP Diesel)

• BORG WARNER 178787 — 87mm • 0.90 A/R • T4
• BORG WARNER 178789 — 87mm • 1.10 A/R • T4
• BORG WARNER 178790 — 87mm • 1.25 A/R • T4

FAQ

Will this housing fit my S400 with an 87mm turbine wheel?

Yes. Part 178788 is sized for the S400 87mm turbine wheel and uses a T4 divided inlet for twin-scroll manifolds.

What outlet does it use?

Half Marmon 4.62" outlet for common S400 downpipe connections.

How does 1.00 A/R compare to .90 or 1.10?

1.00 A/R offers a balance of spool and top-end. Choose .90 A/R for quicker response, 1.10/1.25 for more top-end flow.

Is the inlet truly twin-scroll (divided)?

Yes—T4 divided volute to maintain pulse energy and improve turbine efficiency.

Specifications for BORG WARNER 178788