Manifolds
Diesel Exhaust Manifolds | 5.9L & 6.7L Cummins, 4BT/3.9L, ISX15/X15
Precision-cast, crack-resistant diesel manifolds engineered for airflow, heat control, and long service life. Options for light-duty Cummins pickups and heavy-duty ISX/X15 platforms.
High-Flow Exhaust Manifolds Designed to Reduce Drive Pressure
Diesel Power Source manifolds are built to move heat and exhaust efficiently so your turbo can spool quickly, while keeping EGT’s lower. Thick-wall castings, press-fit, pressure tested joints, and precision-machined flanges help reduce warping and leaks. Choose direct-fit stock-replacement or performance configurations (including T3, T4, T4i and T6) tailored to your engine and turbo setup.
Shop by platform
- 6.7L Cummins Manifolds – Stock-replacement and T4 options for 2007.5–2024 Ram.
- 5.9L Cummins Manifolds – 12V, 24V, and common-rail applications.
- ISX15/X15 Manifolds – Heavy-duty solutions for Class 8 routes.
- Cummins 4BT/3.9L Manifolds – Compact performance for swaps and industrial.
Why upgrade your diesel exhaust manifold
- Lower drive pressure & EGT: CFD tested & designed for improved flow, quicker spool and reduced backpressure. under load.
- Faster turbo response: CFD (fluid dynamically) designed with proper divider locations, runner diameter and flow for faster spool.
- Strength & durability: Multi-piece press-fit design prevents cracking and ensures longevity.
- Service friendly: Pre-tapped ports for pyro or pressure sensors.
Construction that matters
- Precision casting & machining: Press-fit and pressure tested for exact fit on the head.
- Thermal management: Multi-piece designs that tolerate continuous load, heat cycling, and excellent for towing.
- Correct flange geometry: T3/T4/T4i/T6 styles for common turbo inlets.
How to choose the right manifold
- Keep your stock turbo? Pick a direct-fit stock-replacement manifold for OEM flange and angle.
- Upgrading the turbo? Match the flange to whatever size turbo you are using.
When to replace your manifold
- Ticking or hissing on cold start that fades warm (leak at gasket or crack).
- Visible cracks/soot marks near divider walls or flange edges.
- Higher EGT/Turbo lag with no other system changes.
- Warped flanges or recurring gasket failures.
Install & maintenance tips
- Use new gaskets and quality hardware; follow factory torque sequence in stages.
- Re-torque after initial heat cycles if specified.
- Upgrade to our bolt/stud kit upgrades.
Planning supporting upgrades? See 3rd Gen Swap Kits, Add-A-Turbo Kits, and Turbonator® VGT Upgrades.
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Manifolds - Frequently Asked Questions
Factory manifolds are built for cost and packaging, not performance. Upgrading to a performance exhaust manifold can reduce drive pressure, improve airflow to the turbo, lower exhaust gas temperatures, and support higher horsepower and torque.
Yes. Lower backpressure and steadier turbo operation can help manage heat and drivability with factory systems in place when installed as directed.
Most of our manifolds are designed as direct bolt-on replacements for the factory manifold. They use factory mounting locations and are intended to install without custom fabrication. Always check the product description for specific fitment details.
New gaskets are recommended. Replace stretched or corroded studs/nuts. Always follow the correct torque pattern.
