T6 Exhaust Manifold for Cummins ISX / ISX15 / X15 | Fits S400, S410, and All T6-Flange Turbos | 2008–2024
The Diesel Power Source® T6 Exhaust Manifold is designed for 2008–2024 Cummins ISX, ISX15, and X15 engines converting from a factory Holset VGT turbo to a BorgWarner S400, S410, or any T6-flange turbocharger. This manifold replaces the factory exhaust manifold with a T6 turbo mount flange, providing the foundation for an S400 turbo conversion on previously deleted trucks.
Built from High-Silicon Molybdenum Ductile Iron (HSMD) and engineered using CFD (Computational Fluid Dynamics) testing, this 3-piece manifold directs pulse exhaust flow to the divided dual-scroll T6 turbine for faster spool-up, lower exhaust gas temperatures, and improved airflow compared to the factory manifold and turbo setup.
This is NOT a stock turbo replacement manifold. The T6 turbo mount flange is designed exclusively for S400-series and other T6-flange turbochargers. If you need a manifold for your factory Holset VGT turbo, see our Non-EGR Exhaust Manifold or EGR Exhaust Manifold.
What's Included
- (1) DPS T6 3-piece exhaust manifold for Cummins ISX / ISX15 / X15
- Ceramic coated finish (1000° or 1800° based on selection)
- Pre-tapped pyro and pressure sensor ports
Optional Upgrades (Available Above)
- Hardware & Gasket Kit — Bolt & Spacer (OEM-Style) — adds the multi-section MLS gaskets, T6 divided turbo flange gasket, oil drain gasket, OEM-style bolt-and-spacer manifold mounting hardware, and T6 turbo flange hardware (2 studs, 2 bolts, 4 serrated nuts) needed to complete a full manifold and T6 turbo install.
- Hardware & Gasket Kit — Stud & Nut (Performance Upgrade) — same gasket scope and T6 turbo hardware as the Bolt & Spacer kit, with stud-and-nut manifold mounting and serrated flange nuts. Built for high-boost, race, sled-pull, and competition applications where cylinder pressure and fastener pre-load matter.
Installation Notes
- One of the upgrade kits is required to complete the install — the manifold ships bare without gaskets or mounting hardware.
- Choose the Bolt & Spacer kit for moderate-performance street and S400-conversion builds; choose the Stud & Nut kit for high-boost, race, sled-pull, and competition applications.
- The DPS multi-piece manifold requires the matching gasket set included in either upgrade kit — single-piece gaskets will not seal correctly across the expansion-joint architecture.
- This T6 manifold is designed for aftermarket S400-series and other T6-flange turbochargers. It does not fit factory Holset HE400VG, HE451VE, or HE561VE turbos.
Sold Separately (not included in any kit)
- Turbo oil supply line
- Turbo oil drain line
- Turbocharger — this manifold fits any T6-flange turbo. See: S400 Turbo for T6 ISX
Why Do You Need a T6 Manifold?
The factory Cummins ISX exhaust manifold uses a rectangular turbo mounting flange designed for the Holset HE561VE (CM871), HE451VE (CM2250/CM2350), or HE400VG (late X15). BorgWarner S400-series turbochargers use a completely different exhaust inlet: the T6 twin-scroll flange. The factory manifold cannot bolt directly to an S400 turbo because the flange pattern and geometry don't match.
This DPS T6 manifold solves the problem by using the same head-side bolt pattern as the factory manifold (so it bolts directly to your ISX cylinder head) while replacing the turbo-side flange with a T6 mount designed specifically for S400-series turbos. The divided dual-scroll T6 design also improves exhaust pulse energy delivery to the turbine compared to the factory single-scroll arrangement.
Key Features
- T6 Twin-Scroll Turbo Mount — Fits BorgWarner S400, S410, S475, S478, S480, S483, S488, and any T6-flange turbocharger
- 3-Piece Press-Fit Design — Front section, center turbo mount section, and rear section are hydraulically pressed together. This allows independent thermal expansion while eliminating the exhaust leaks common in factory seal-type manifolds.
- HSMD Ductile Iron Construction — High-Silicon Molybdenum Ductile Iron resists cracking, warping, and thermal fatigue under the sustained heat cycles of commercial duty
- CFD-Tested Flow — Computational Fluid Dynamics tested to reduce turbulence, eliminate hot spots, and direct pulse exhaust energy efficiently to the T6 dual-scroll turbine
- Dual-Scroll Divider — Separates exhaust pulses from cylinder groups for improved turbine response and faster spool-up
- Ceramic Coated — Available in two coating options for heat resistance and corrosion protection
- Pre-Tapped Sensor Ports — Ready for pyro and pressure sensor installation
- Direct Bolt-On to ISX Head — Uses factory cylinder head bolt pattern, no modifications required
Ceramic Coating Options
| Coating Option | Temperature Rating | Best For |
|---|---|---|
| Standard Ceramic | Rated up to 1,000°F | Normal operating conditions, daily driving, standard towing |
| Premium Ceramic (+$250) | Rated up to 1,800°F | Heavy haul, sustained high-load conditions, performance tuning, extreme heat environments |
Both coatings provide corrosion protection and improved heat management. The 1800° premium coating is recommended for trucks running higher horsepower tuning, sustained mountain grades, or operating in high ambient temperature environments.
Fitment
This T6 manifold fits Cummins ISX and ISX15 engines with CM871, CM2250, CM2350, and X15 ECM platforms (2008–2024). It is designed for previously deleted, non-emissions trucks converting to an S400-series or other T6-flange turbocharger. Diesel Power Source® does not sell or support emissions delete components.
Please provide your Cummins Engine Serial Number (ESN) when ordering so we can verify compatibility.
OEM Part Numbers Replaced
This DPS T6 manifold replaces the center turbo-mount section of the factory exhaust manifold with a T6 flange. The factory manifolds commonly replaced include:
- 3687032 — Factory EGR manifold assembly (CM2250/CM2350)
- 3687063 — Factory EGR manifold assembly (CM871/CM2250)
Note: The factory manifolds listed above use a rectangular Holset turbo flange. This DPS manifold replaces them with a T6 flange specifically for S400-series turbo conversions.
Tuning / Programming
Converting from a factory Holset VGT turbo to a fixed-geometry S400 turbo changes the airflow and boost characteristics of the engine. ECM tuning or programming is typically required after installing this manifold and turbo to optimize fueling, boost targets, and drivability for the new turbo configuration. Work with an experienced Cummins tuner who can calibrate the ECM for S400 turbo operation on your specific engine platform.
Which ISX Manifold Do You Need?
Diesel Power Source® offers three ISX15 / X15 exhaust manifold options. Choosing the right one depends on your turbo configuration:
| Manifold | Turbo Compatibility | Best For |
|---|---|---|
| T6 Exhaust Manifold (this product) | S400, S410, S475, S478, S480, any T6-flange turbo | S400 turbo conversions on deleted trucks |
| Non-EGR Exhaust Manifold | Factory Holset VGT (HE400VG, HE451VE, HE561VE) | Deleted trucks keeping factory-style VGT turbo, no EGR port |
| EGR Exhaust Manifold | Factory Holset VGT (HE400VG, HE451VE, HE561VE) | Direct OEM replacement with EGR port and bellows connection |
Want the Complete Conversion?
If you need the T6 manifold, turbo, and all piping/hardware in one package, see the S400 Cummins ISX Complete Turbo Conversion Kit. This kit includes the DPS T6 manifold (the same manifold sold on this page), an S400 turbo (S475, S478, or S480), and all piping, oil lines, and installation hardware.
If you already have your turbo and only need the piping and hardware (no manifold), see the S400 ISX Turbo Conversion Kit (Piping and Hardware Only).
Why Choose Diesel Power Source?
- CFD-Tested Airflow — Every manifold is tested using Computational Fluid Dynamics for optimized exhaust flow and pulse energy
- Press-Fit Construction — Hydraulically pressed joints eliminate exhaust leaks common in factory seal-type manifolds
- HSMD Ductile Iron — Resists cracking and warping under sustained commercial-duty heat cycles
- ESN-Verified Fitment — We confirm compatibility before shipment
- Made in the USA
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:
Understanding DPS Multi-Piece Exhaust Manifolds →
Warranty
This Diesel Power Source® T6 Exhaust Manifold includes a 1-year limited warranty and is backed by our technical support team.
Related ISX15 / X15 Products
- S400 Complete Turbo Conversion Kit (Includes This Manifold, Turbo, and All Hardware)
- S400 ISX Turbo Conversion Kit (Piping and Hardware Only)
- ISX15 / X15 Compound Turbo Kit | S472/S488 and S475/S488
- S400 Turbo for T6 ISX (Turbo Only)
- ISX15 / X15 T6 Manifold Hardware Kit — Bolt & Spacer
- ISX15 / X15 T6 Manifold Hardware Kit — Stud & Nut
- Non-EGR Exhaust Manifold
- EGR Exhaust Manifold (Direct OEM Replacement)
Frequently Asked Questions
The factory Cummins ISX exhaust manifold uses a rectangular turbo mounting flange designed for Holset VGT turbochargers (HE561VE, HE451VE, HE400VG). BorgWarner S400-series turbochargers use a T6 twin-scroll exhaust inlet flange, which is a completely different bolt pattern and geometry. This DPS T6 manifold bolts directly to the ISX cylinder head using the factory bolt pattern while providing the correct T6 turbo mount for S400-series turbos.
This manifold fits any turbocharger with a T6 exhaust inlet flange. Common compatible turbos include the BorgWarner S400, S410, S475, S478, S480, S483, and S488. It also works with the Diesel Power Source® Turbonator® VGT exhaust housing, which adds variable geometry exhaust braking to any compatible S400-series turbo.
No. This manifold is designed exclusively for S400 turbo conversions on deleted trucks. The turbo-side flange is a T6 mount that does not fit factory Holset VGT turbochargers. If you need a direct replacement manifold for your factory turbo, see the Non-EGR Exhaust Manifold (for deleted trucks keeping their factory VGT) or the EGR Exhaust Manifold (direct OEM replacement with EGR port).
Both coatings provide corrosion protection and heat management. The standard 1,000°F coating is suitable for normal operating conditions and daily driving. The premium 1,800°F coating (+$250) is recommended for heavy haul, sustained high-load conditions, aggressive tuning, and extreme heat environments where the manifold is exposed to higher sustained exhaust temperatures
1 Review
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T6 Manifold
This manifold arrived speedy quick. Great for my deleted cummins rig. Running much better and spool up quicker with the manifold already.
