Calibrated Power Stealth STR 63/66 Drop In Turbo 24-26 GM 6.6L Duramax L5P

The Stealth STR 63/66 Drop-In Turbo is an excellent upgrade for L5P Duramax owners who want more power, improved towing performance, and greater reliability without stepping into an oversized turbo setup. Designed to deliver a noticeable increase in airflow while maintaining factory-like spool-up and throttle response, the Stealth STR supports builds producing up to 625 horsepower with the proper supporting modifications, even with emissions equipment retained. It works with factory tuning, box tuners, or custom tuning, making it a versatile option for daily drivers, work trucks, and tow rigs looking for stronger performance without the complexity of a full custom turbo conversion. The Stealth STR features a custom 62.5mm, 7+7-blade extended-tip billet compressor wheel manufactured from 2618 aluminum alloy, paired with a larger 66.4mm, 9-blade turbine wheel constructed from 713C nickel alloy. Its upgraded turbine design features thicker blades for improved heat tolerance and an aggressive blade angle that captures exhaust energy more effectively, helping reduce drive pressure and exhaust gas temperatures under heavy loads. The rotating assembly is approximately 6% lighter than stock and precision-balanced in-house to promote quick spool-up and responsive power delivery. These upgraded components are engineered to handle demanding operating conditions while delivering improved airflow and durability over the factory configuration. Designed as a direct-fit replacement for 2024–2026 GM HD trucks equipped with the 6.6L Duramax, the Stealth STR retains factory variable-geometry turbo operation and exhaust brake functionality. Its compressor-and-turbine combination is designed to help prevent compressor surge during towing while delivering the distinctive turbo whistle that enthusiasts appreciate. Each unit features brand-new components, eliminating the need for a core exchange, and is backed by a 12-month warranty. For reliable operation, tuning must retain the factory minimum and maximum vane-position tables to avoid excessive boost and exhaust pressure that could damage the turbo or engine. With its combination of increased airflow, towing-friendly response, and straightforward installation, the Stealth STR is a practical performance upgrade for trucks that work hard and still need to drive comfortably every day.