Product Description
Push your L5P beyond the CP4/HP4 limits. The S&S Diesel Motorsport L5P-CP3-14 kit converts your 2017–2023 GM Duramax 6.6L L5P to a high-output 14mm CP3 for serious competition builds. Engineered with OE-grade components, quick-disconnect fittings, braided supply lines, and an injection-molded ECU mount for a clean, factory-like install.
Competition use only. Tuning is required for CP3 conversion on L5P applications. See Helpful Notes below.
Fitment
- 2017, 2018, 2019, 2020, 2021, 2022, 2023 Chevrolet Silverado / GMC Sierra 2500HD & 3500HD – 6.6L Duramax L5P
What’s Included
- Brand-new S&S 14mm CP3 high-pressure pump (competition spec)
- OE-style quick-disconnect fittings and braided supply line
- High-pressure lines from CP3 to factory rails
- Injection-molded ECU relocation/mount bracket
- Feed/return fittings and installation hardware
- Detailed install guidance (use with professional tuning)
Why CPP Diesel
- Genuine S&S Diesel Motorsport components
- HD diesel experts, fast shipping, and phone support
- Built-to-race solutions that outlast and outperform
Recommended Parts (Internal Links)
- Lift Pumps & Filtration (FASS/AirDog) – ensure stable low-pressure supply for high-output CP3
- L5P Fuel Injectors – match injector flow to your power goals
- Fuel Rails, Lines & Fittings – upgrade ancillary hardware as needed
- Custom Tuning – required for CP3 conversion on L5P competition builds
- S&S Diesel Motorsport Catalog – more S&S L5P components
Helpful Notes
- Tuning required: The L5P CP3 conversion is competition-only and requires professional calibration.
- Fuel supply: For 12mm/14mm pumps, feed with 1/2"–5/8" hose; the 14mm return line should be 1/2". Consult your tuner for target lift-pump pressure.
- ECU mount & OE-style hardware: Kit includes an OE-quality injection-molded ECU mount and quick-disconnects for a tidy, serviceable install.
FAQ: Is this legal for street use?
No. This is a competition-use-only conversion and is not emissions compliant for on-road use.
FAQ: Do I need custom tuning after the conversion?Yes. L5P CP3 conversions require professional calibration to operate correctly and safely in competition applications.
FAQ: What low-pressure (lift) pump setup is recommended?Use a quality lift pump and adequate hose size (1/2" or 5/8" feed, 1/2" return for 14mm). Work with your tuner on target supply pressure.
FAQ: Does the kit include high-pressure lines and an ECU mount?Yes. It includes new high-pressure lines to the factory rails and an OE-quality injection-molded ECU mount for a clean install.
FAQ: How much power can a 14mm CP3 support?The 14mm is intended for 1000+ rwhp competition builds when supported by proper fuel system, injectors, air system, and tuning.
