What is a twin scroll turbine housing?

A twin scroll housing uses two separate exhaust entry paths that lead to the turbine wheel. This design helps to keep exhaust pulses separated, improving exhaust gas velocity and leading to quicker turbocharger spool-up.

What does the A/R ratio mean on a turbine housing?

The A/R ratio (Area/Radius) indicates the size of the turbine housing's internal passages. A higher A/R like 1.25 generally means more exhaust flow at higher RPMs, while a lower A/R would favor quicker spool at lower RPMs.

Can this housing be used on any turbocharger?

This specific turbine housing is designed for BorgWarner S400 turbochargers. While it uses a common T4 flange, the internal dimensions and wheel size are matched to the S400 series for optimal performance.

BorgWarner S400 Turbine Housing 1.25 A/R 177105

Name: BorgWarner Turbine Housing SX S400 T4 A/R 1.25 83/74mm Twin Scroll
Brand: BorgWarner
SKU: borgwarner-borgwarner-turbine-housing-sx-s400-t4-a-r-1-25-83-74mm-twin-scroll-t14-4385273
Price: 315.94 USD
Availability: InStock

BorgWarner Turbine Housing SX S400 T4 A/R 1.25 83/74mm Twin Scroll

$315.94

Only 6 left in stock

BorgWarner S400 Twin Scroll Turbine Housing with a 1.25 A/R ratio for improved exhaust flow.

Key Features

Fits BorgWarner S400 turbochargers.
Twin scroll design improves exhaust flow and turbo spool.
T4 flange for versatile mounting options.
1.25 A/R ratio balances exhaust flow and responsiveness.
Features an 83mm turbine wheel with a 74mm exducer diameter.
Not CARB approved; cannot ship to California.

This turbine housing is designed for BorgWarner S400 turbochargers. Always confirm compatibility with your specific turbocharger model and build requirements.

Secure CheckoutFast Shipping631-982-0042

Product Details

If you're building a custom turbo system for your performance vehicle and need a robust turbine housing, this BorgWarner SX S400 housing is a solid choice. It's designed for twin-scroll applications, meaning it uses two separate entry paths into the turbine wheel. This setup helps improve exhaust gas velocity at lower RPMs, leading to quicker turbo spool and a more responsive engine.

This housing features a T4 flange and an A/R ratio of 1.25, which is a good balance for many high-performance applications. The 83mm turbine wheel with a 74mm exducer diameter is well-suited for engines that need to move a lot of air. BorgWarner is known for making well-built turbo components, and this housing is no exception. It's made to handle the heat and pressure of forced induction, ensuring reliable performance when you need it most.

Keep in mind that this part is not CARB approved and cannot be shipped to California. Always refer to your specific build plans and local regulations when selecting turbo components.