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DPS Cummins ISX15 / X15 Non-EGR Exhaust Manifold - Stock Turbo - 2010–2025
Choose Options$1,149.00 - $1,399.00 -
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ISX15 Manifold
ISX15 / X15 Exhaust Manifolds | Cummins Semi and Heavy-Duty | 2010 to 2025
Press-Fit 3-Piece Manifolds for Class 7 and Class 8 Commercial Trucks
Diesel Power Source® ISX15 and X15 exhaust manifolds increase exhaust flow by up to 22%, reduce EGTs by approximately 75 to 100°F, and eliminate the joint seal leaks that commonly develop on factory manifolds during sustained commercial duty.
Factory ISX15 manifolds use seal-type joints between sections that degrade over time from soot, heat cycling, and vibration. When these joints fail, exhaust leaks develop that reduce turbo efficiency, raise EGTs, and can lead to roadside breakdowns. DPS ISX15 manifolds replace these seal-type joints with hydraulically pressed metal-to-metal connections that get tighter as temperature increases. Combined with High Silicon Molybdenum Ductile Iron (HSMD) construction and CFD-optimized runner geometry, the result is a manifold built for the sustained load, extreme heat, and long duty cycles that Class 7 and Class 8 trucks demand.
22% More Exhaust Flow
CFD-tested runner geometry reduces backpressure and drive pressure
75 to 100°F Lower EGTs
Improved flow reduces exhaust temperatures under sustained load
Press-Fit 3-Piece Design
Hydraulic joints eliminate the seal leaks common on factory manifolds
HSMD Ductile Iron
Resists cracking, warping, and center divider erosion
ISX15 / X15 Manifolds by Configuration
- ISX15 EGR Exhaust Manifold (2010 to 2025) — Press-fit 3-piece. Retains full EGR function with bellows connection. U-shaped loop on EGR side (asymmetric design). For emissions-intact trucks. Available in standard (1,000°F) or premium (1,800°F) ceramic coating.
- ISX15 Non-EGR Exhaust Manifold (2010 to 2025) — Press-fit 3-piece. No EGR feed port. Direct exhaust flow to turbocharger. Symmetric design. Includes bung in elbow for exhaust pressure sensor port. For trucks operating in non-EGR configurations. Available in standard or premium coating.
- T6 ISX Manifold (2008 to 2024) — T6 flange for S400 conversion kits. For trucks converting from factory VGT to S400 single turbo. For non-EGR configurations only.
EGR vs Non-EGR: Which ISX15 Manifold Do I Need?
- Truck still has EGR system intact: Choose the EGR manifold. It retains the bellows connection for EGR flow and maintains full emissions function.
- Truck is operating in a non-EGR configuration: Choose the Non-EGR manifold. It eliminates the EGR port and provides a direct, uninterrupted exhaust path to the turbocharger. The Non-EGR manifold includes a bung for the exhaust pressure sensor so the ECU can still communicate even without EGR.
- Converting to S400 single turbo: Choose the T6 ISX manifold. This is for S400 conversion kits on trucks in non-EGR configurations.
DPS does not advise on deletion procedures or their legality. The Non-EGR and T6 manifolds are designed for trucks that have already been configured for non-EGR operation.
Ceramic Coating Options
- Standard ceramic (up to 1,000°F): Provides corrosion protection and thermal management for most standard commercial duty cycles.
- Premium Cerakote (up to 1,800°F): Recommended for higher duty cycles, extended idle, elevated EGT applications, and heavy hauling in hot climates or mountain grades.
If coating discolors to gray or white, the manifold has exceeded its coating temperature rating. This indicates an underlying engine heat issue that should be addressed. Coating discoloration may void warranty on a case-by-case basis.
Construction and Materials
- Material: High Silicon Molybdenum Ductile Iron (HSMD)
- Design: Press-fit 3-piece with hydraulically pressed expansion joints
- Flow improvement: Up to 22% more exhaust flow than factory (CFD tested)
- EGT reduction: Approximately 75 to 100°F under sustained load
- Turbo spool improvement: Approximately 200 RPM earlier spool on ISX15 applications
- Pressure tested: 100% of manifolds pressure-tested before shipping
- Pre-tapped ports: OEM sensor port, pyrometer port, and pressure port (both 1/8" and 1/4" NPT on ISX15 manifolds)
Fitment and Ordering
DPS ISX15 manifolds fit Cummins ISX15 and X15 engines from 2010 to 2025 on CM871, CM2250, and CM2350 platforms (and select X15 variants). Compatible with Freightliner, Peterbilt, Kenworth, Volvo, International, and Western Star trucks.
ESN (Engine Serial Number) is required at time of order for ALL ISX15/X15 applications. Semi trucks have many chassis-specific variants. DPS verifies the ESN to confirm the correct manifold version before shipment.
Installation Notes
- Turbo-to-manifold torque: 48 ft-lbs
- After installation, drive approximately 100 miles then re-torque all manifold and turbo bolts while warm (gloves required)
- Anti-seize is NOT required or recommended by DPS. Customer discretion only.
- For EGR version: connect bellows pipe to EGR system
- For Non-EGR version: attach ECU pressure sensor line to the pre-installed bung/fitting
- Always use new gaskets and recommended hardware
Bundle Options
Replacing the turbo and manifold together reduces labor time and ensures proper alignment between components.
- HE400VG Turbo and Manifold Kit — Includes DPS HE400VG turbo (67mm or 70mm), manifold (EGR or Non-EGR), and complete hardware kit at a package price.
- Exhaust Manifold Hardware Kit — Complete stud, nut, and hardware set for manifold installation.
- Stud and Nut Kit — Studs and nuts only.
Related categories: 5.9 Cummins Manifolds | 6.7 Cummins Manifolds | ISX Turbocharger Kits | ISX Conversion Kits | ISX Compound Turbo Kit
ISX15 / X15 Cummins Exhaust Manifold FAQs
A high-flow ISX15/X15 exhaust manifold improves exhaust gas distribution to the turbocharger, reducing drive pressure and helping control EGTs during sustained load. Compared to factory manifolds, performance designs support steadier boost, better grade-pulling consistency, and improved long-term sealing reliability for heavy-duty and high-mileage applications.
Yes. Diesel Power Source ISX15 and X15 exhaust manifolds are engineered for specific engine families such as CM871, CM2250, and CM2350. When the correct manifold is matched to the engine family and installed properly, trucks can retain factory emissions equipment while benefiting from improved airflow and reduced exhaust restriction.
In most cases, a manifold upgrade alone does not require calibration changes. Many fleets and owner-operators see reduced drive pressure, cooler EGTs, and more consistent pulling power under load without altering the engine tune. If additional airflow or fueling modifications are present, calibration review may be appropriate to optimize boost and regeneration behavior.
If you’re looking for dependable ISX or ISX15 exhaust manifolds, you want parts that are built for heavy use, engineered to fit right, and backed by real support. You can find high-quality options through specialty diesel performance shops and aftermarket manufacturers that focus specifically on Cummins engines. At Diesel Power Source, we offer exhaust manifolds that are designed with strength, longevity, and real-world performance in mind. Our manifolds are made from thick, durable castings and go through stringent quality checks before they reach you. That means less worry about cracks, leaks, or premature failure compared with stock units or low-cost replicas. Diesel Power Source manifolds are a great option because they’re built by people who understand what ISX and ISX15 engines go through day in and day out. Whether you’re replacing a worn-out OEM piece or upgrading for better performance, our manifolds deliver reliability, fitment you can trust, and performance gains without sacrificing durability.
Yes, you can absolutely upgrade your Cummins ISX exhaust manifold for better performance. Upgrading to a higher-quality manifold can improve exhaust flow, reduce backpressure, and help your turbo work more efficiently. That translates into more consistent power delivery, better throttle response, and sometimes improved fuel economy, especially under load. Choosing an upgraded manifold also reduces the chance of thermal cracking and gasket issues that are common with stock units on high-output engines. Diesel Power Source manifolds are a solid performance upgrade because they’re engineered to handle higher temperatures and increased flow without the weak points that cause stock units to fail. They bolt in where the factory manifold goes but give you stronger construction and better thermal characteristics. For anyone running higher boost levels, heavier duty cycles, or just wanting a more robust exhaust setup, our ISX and ISX15 manifolds are an effective way to get a noticeable improvement without major engine modification.
