Looking for the best 5 inch exhaust options for an LMM (LMM refers to late-model GM 6.6L Duramax engines commonly paired with 5 inch turbo back systems)? This guide highlights five practical choices, explaining who each is best for, and why. Whether you’re after durability, improved exhaust flow, or a deeper tone, these selections cover common needs for truck owners, diesel enthusiasts, and performance-minded drivers.
Below is a quick, buyer-friendly overview of the five products selected for this topic. The table helps compare core attributes at a glance to support an informed decision.
| Product | Best For | Notes |
|---|---|---|
| 5″ Inch Chrome Curved Exhaust Stack Pipe | Durability seekers; chrome finish lovers | 60″ long, 5″ OD, 1.6 mm, polished chrome |
| LCGP 5 Inch Straight Exhaust Pipe | Straight run replacements; ease of install | 30″ length; mandrel bends |
| MBRP S5259AL 4″ Cat Back | Aluminized steel enthusiasts | 4″ system; welded hangers; tip included |
| 5 inch Diesel Exhaust Tip Elbow | Elbow/tip customization | 5″ inlet to 6″ outlet; 23″ long |
| Turbo Flange Adapter for T3/T4 Turbo | Turbo upgrade compatibility | 5-bolt to 3″ V-band; stainless |
5″ Inch Chrome Curved Exhaust Stack Pipe, 5″ OD x 60″ Long
Best for durability and a polished chrome finish, this exhaust stack pipe is crafted from high-quality alloy steel with computerized mandrel bends. It measures 5″ OD and 60″ long, with a wall thickness of 1.6 mm. The chrome-plated surface is designed to resist corrosion while maintaining a mirror-like shine. This option suits buyers who want a long, curved stack that handles high-pressure exhaust with strong structural integrity.
- Best for: Owners seeking a robust chrome finish and heavy-duty construction.
- Why selected: The combination of mandrel bends and alloy steel provides enhanced flow and durability.
- Caution: Surface finish may require periodic cleaning to maintain mirror chrome appearance.
LCGP 5 Inch Straight Exhaust Pipe
This 5″ stainless steel straight pipe is designed for straightforward exhaust replacement. It features mandrel bends and includes two lap joint band clamps, offering solid, simple installation for a clean straight path. It’s a practical choice when a direct exhaust route is desired without complex curves.
- Best for: Breathing space for easy, no-fruss installation projects.
- Why selected: Straight design reduces potential flow restrictions compared to curved variants.
- Caution: Shorter length may not suit all configurations; verify fitment with your vehicle’s undercarriage.
MBRP S5259AL 4″ Cat Back, Single Exhaust System
MBRP’s 4″ aluminized steel cat-back system provides a reliable, rust-resistant option with welded hangers and a included tip. While this is a 4″ system rather than 5″, it’s included here for buyers considering close-fit alternatives or stepping down in diameter for specific performance or clearance needs. It’s best for those prioritizing proven durability in a balanced exhaust package.
- Best for: Those seeking a durable aluminized steel system with practical installation features.
- Why selected: Emphasizes proven fit and finish with included tip and sturdy hangers.
- Caution: Not a 5″ kit; ensure diameter compatibility with your intended build.
5 inch Diesel Exhaust Tip Elbow
This 5″ inlet to 6″ outlet exhaust elbow provides a versatile option for diesel exhaust configurations. The 23″ length and 2 mm (14 gauge) wall thickness offer a sturdy, slightly extended outlet with compatibility for 5″ inlet systems. It’s better for drivers aligning a custom path with an elbow design rather than a straight run.
- Best for: Custom exhaust routes requiring an angled elbow connection.
- Why selected: Combines a flexible geometry with sturdy gauge steel to manage exhaust flow.
- Caution: Not a complete system; needs compatible pipe and mounting hardware.
Turbo Flange Adapter for T3/T4 Turbo
This flange adapter converts a T3/T4 turbocharger 5-bolt discharge to a 3″ V-band connection. It’s a high-performance upgrade item designed for secure, leak-free exhaust transitions under extreme boost. Stainless construction improves heat resistance and corrosion protection, supporting long-term exhaust system reliability.
- Best for: Upgrading or configuring turbocharger-to-exhaust connections.
- Why selected: Supports robust exhaust flow and reliable sealing under high pressure.
- Caution: Specific to turbocharger configurations; confirm compatibility with your setup.
Buying Guide
What diameter and layout matter?
Diameter impacts exhaust flow and turbo response. A 5″ system is typically chosen for larger builds or turbo-enabled trucks where maximum flow is desired. Straight runs can simplify installation, while curved stacks may fit limited spaces or aesthetic goals.
Materials and finish: chrome, aluminized steel, stainless?
Chrome-plated steel offers a polished look and corrosion resistance, but chrome requires maintenance to retain shine. Aluminized steel provides durable protection at a lower cost, while stainless steel offers superior heat resistance and longevity in harsh environments.
Install considerations
- Check fitment against existing undercarriage components and clearance.
- Consider mandrel bends for smoother flow and fewer restrictions.
- Ensure you have compatible clamps, hangers, and gaskets for a leak-free connection.
Performance and sound goals
Diesel exhaust choices influence tone and throttle response. A longer stack or curved design can alter the exhaust note and the perceived power delivery. For some builds, a tighter elbow or adapter provides the needed geometry to optimize flow at the turbo outlet.
Installation tips
- Plan the route to avoid heat sources, moving parts, and road debris.
- Use proper torque on clamps to prevent exhaust leaks.
- During installation, verify there are no exhaust leaks at joints by starting the engine and listening for air leaks.
FAQ
- What is a turbo back exhaust?
It’s a complete exhaust system from the turbo outlet to the tailpipe, designed to improve flow and sometimes sound. - Do I need a 5″ system for my LMM Duramax?
Not always; choose based on your vehicle’s configuration, turbo size, and desired performance. - Is stainless steel better than aluminized for exhausts?
Yes, stainless offers higher heat resistance and longer life, especially in harsh environments. - Can I mix sections from different brands?
Only if the connections are compatible and designed to seal properly under pressure. - What should I inspect before buying?
Look for proper fitment, the presence of mandrel bends, and the suitability of finish for your climate. - Are these options compatible with all diesel engines?
Compatibility depends on pipe diameter, inlet/outlet connections, and mounting hardware specific to the truck.