L5P/L5D Stealth STR (63mm) Turbo

Performance & Fitment Overview

If you’re driving a 2024 or 2025 Chevrolet/GMC truck equipped with the 6.6L L5P or L5D Duramax engine, this direct-fit turbocharger upgrade delivers more than mere replacement — it’s a step up in performance and reliability. It bolts directly in as an OEM‐style fit for the appropriate models (Silverado/Sierra 2500–6500 & certain medium duty Internationals) and offers support for up to ~625 hp with supporting modifications.

Despite the upgraded internals, the STR is designed so that if your truck is mostly stock you can install it and continue driving — minimal special tuning required to start, thanks to the conservative factory-compatible vane tables

1. High‐Flow Compressor Wheel

• 63 mm billet compressor wheel with 7×7 blade design: stronger, lighter, and optimized for a wide efficiency range.

• Delivers about 66 lbs/min mass airflow vs ~60 lbs/min stock.

• Faster spool up and better responsiveness under load.

2. Upgraded Turbine Assembly

• Custom 9-blade turbine wheel, larger than stock, with aggressive blade angles for improved exhaust energy capture.

• 50 % thicker turbine blades for enhanced heat tolerance and longer life under heavy use.

• Produces a distinct “turbo whistle” signature sound under boost – more pronounced than stock, giving an auditory cue of its performance.

3. Lightweight, Balanced Rotating Assembly

• The combined compressor/turbine rotating assembly is ~6 % lighter than stock, which helps reduce drive pressure, improve spool, and maintain efficiency.

• Precision‐balanced in‐house for optimal high‐RPM stability.

4. Direct Drop-in Installation + Emissions Friendly

• Designed for the factory 2024–25 L5P/L5D platform with minimal fuss. You get the convenience of a nearly plug-and-play install, with the bonus of upgraded capability.

• Compatible with stock emissions equipment; supports up to 625 hp while retaining emission systems intact (with supporting mods).

• No core return required: brand new parts, no reman or core swap

While the STR supports up to ~625 hp, supporting modifications are required to reliably hit that level (fueling, intake, exhaust, tuning, etc.).

To maintain warranty and safe operation, tuning must retain the stock minimum and maximum vane position tables. Departing from these can lead to excessive exhaust pressure, reduced turbo life, or void warranty.

Because of the increased airflow and performance, ensure your charge‐air system, intake, intercooler, and exhaust paths are in good condition (no leaks, proper flow) to fully take advantage.

Install should be done with proper torque specs, fresh gaskets, and attention to cleanliness, especially given the high precision nature of the billet and turbine components.