Built for serious airflow and serious power.
This 12V Cummins T4 exhaust manifold is designed to support larger frame turbos, improve exhaust flow, and reduce drive pressure on high-performance 5.9L builds.
When upgrading a 12 valve Cummins for more boost and power, the factory manifold quickly becomes a restriction. This 12V Cummins T4 exhaust manifold is engineered for high-flow performance applications where reliability and airflow matter.
Designed specifically for 5.9L 12 valve Cummins engines (1989–1998), this manifold features a T4 turbo mounting flange, making it ideal for S300 and S400 frame turbochargers, compound turbo setups, and high-horsepower single turbo builds.
The optimized runner design improves exhaust gas flow to the turbocharger, helping reduce drive pressure, support higher boost levels, and improve overall turbo efficiency. Built from high-strength cast material, this manifold is designed to withstand extreme exhaust temperatures and high EGTs common in performance diesel applications.
Whether you’re building a street truck, tow rig, or competition setup, this T4 manifold provides the foundation needed for reliable power gains.
Key Features & Benefits
- Direct fit for 12V Cummins 5.9L (1989–1998)
- T4 turbo flange supports larger turbochargers
- Improved exhaust flow vs stock manifold
- Reduces exhaust backpressure and drive pressure
- Supports single turbo and compound turbo setups
- High-strength cast construction for durability
- Designed for high-boost and high-heat diesel applications
- Ideal for performance, towing, and race builds
Vehicle Fitment
- Dodge Ram 2500 / 3500
- 1989–1998
- 5.9L 12 Valve Cummins Diesel
(Always confirm turbo and piping compatibility before installation.)
Common Product Uses / Applications
- T4 turbo conversions on 12V Cummins
- S300 or S400 turbo upgrades
- Compound turbo systems
- High-horsepower street builds
- Heavy towing applications
- Competition and race trucks
- Replacing restrictive or cracked factory manifolds
What This Manifold Solves
- Factory manifold airflow restriction
- Limited turbo options with stock T3 flange
- Excessive drive pressure at higher boost
- Cracked or warped OEM exhaust manifolds
- Inconsistent turbo response on larger setups
About the Manifold Joint Seal
Every DPS multi-piece manifold uses a hard, metal-to-metal press-fit seal at each joint - no gasket. The seal tightens through thermal expansion and performs best at driving temperatures (750°F and higher). Minor leakage at cold or idle is normal and expected on any joint-style manifold and is not a sign of a defective part.
Every manifold is pressure-tested leak-free at room temperature before it leaves our facility. For a full explanation of how the seal works, why soapy-water idle tests aren't a valid diagnostic, and how the multi-piece design outlasts single-piece manifolds, see:
